Distribution Substation Guideline- Of 11-22 KV Substation-26 01 2009

YEAR 20

008 – 1sst Editionn

Table of Contents

Title Page No.

1. General Notes ------------------------------------------------------------------------------------------------------------------- 3

2. General Conditions / Requirements for Approval of Substation [Supply provided at LV (0.4 kV)]:

a. Substation in Ground Floor within Building ------------------------------------------------------------4

b. Split Room Substation in Ground Floor within Building ---------------------------------------------7

c. Split Room Substation in Basement Floor---------------------------------------------------------------11

d. Substation Outside Building – Open to Sky Plot------------------------------------------------------16

e. Pocket Substation Outside Building - Open to Sky Plot-------------------------------------------18

f. Temporary Pocket Substation Outside Building - Open to Sky Plot---------------------------20

3. General Conditions/Requirements for providing Direct 6.6/11/22 KV Supply-----------------------------21

a. Industrial / Special Loads-------------------------------------------------------------------------------

b. High Rise Towers--------------------------------------------------------------------------------------------

4. Annexure------------------------------------------------------------------------------------------------------------------

Annex1: General Conditions/Requirements for Wet Areas above Substation-----------------------------

Annex 2: Guarantee against Damages due to Water Leakages-----------------------------------------------

Annex 3: Wet Area Checklist-------------------------------------------------------------------------------------------------

Annex 4: DEWA Regulations for Electrical Installation--------------------------------------------------------------

Annex 5: Chiller / Motor Loads Proposed to be Connected to DEWA Transformer----------------------

Annex 6: Checklist for Chiller / Motor Loads Proposed to be Connected to DEWA Transformer---

Annex 7: Substation Door Details-------------------------------------------------------------------------------------------

Annex 8: Section T-T-------------------------------------------------------------------------------------------------------------

Annex 9: Section B-B------------------------------------------------------------------------------------------------------------

Annex 10: UNDERTAKING (Ground Floor Split Substation)---------------------------------------------------------

Annex 11: Detail of Fixed Aluminium Wire Mesh/Grill ---------------------------------------------------------------

Annex 12: Diagram of Fixed Ventilation System----------------------------------------------------------------------

Annex 13: UNDERTAKING (Transformer Room in Basement)------------------------------------------------------

Annex 14: Undertaking for Shared Substation-------------------------------------------------------------------------

Annex 15: NOC Demarcation Form---------------------------------------------------------------------------------------

Annex 16: Piont of Supply/Responsibility Diagram ------------------------------------------------------------------

Annex 17: Guidelines of 11-22 kV Network Design------------------------------------------------------------------------

Annex 18: DEWA Meter/Control Room Requirements (High-rise Towers)------------------------------------

Annex 19: Guide Lines for Protection Requirement for Private Substations---------------------------------

Annex 20: Checklist for Private Supply------------------------------------------------------------------------------------

Annex 21: Sample operation philosophy (Interlocking arrangement)---------------------------------------

Annex 22: DEWA Meter/Control Room Requirements (Industrial / Special Loads)-----------------------

GENERAL NOTES 1) Submission of the following services are available on line through DEWA

Website www.dewa.gov.ae :-

a) Distribution Substation Approval b) Request For Distribution Substation Layout Drawing c) Request for Inspection of Distribution Substation

2) Construction of the project should not be commenced prior to getting the

substation approval from DEWA. Otherwise, DEWA will not be responsible for any delay in power supply due to the above.

3) For any additional query on your project, you may send e-mail to

[email protected]. 4) The above guideline and requirements may be revised or modified

without prior notice. It is advised to check the latest requirements within DEWA Distribution Services Department before finalizing your design.

5) For any Patrol station, no Pocket substation to be installed only regular

substation should be install.

General Conditions / Requirements for Approval of Location & Size of Substation(s) in Ground

Floor Within Building (Single Room Option)

1) Substation area requirement:

1-1) 32.56m2 for 1x1000/1500 kVA transformer (with minimum width of 4.57m towards door side)

1-2) 53.95m2 for 2 x1000/1500 kVA transformers (with minimum width of 6.1m towards door

side)

(For every additional transformer, approximately 25 m2 additional space** is required).

** For S/S having four and more transformers, an additional space of (10 m2) shall be required.

2) General Substation Conditions:

2-1) Substation clear height – 3.7m (minimum)

2-2) Directly located on RTA/Public Road or Sikka. 2-3) In case substation is located on Sikka, the sikka should have a minimum clear width of

6.1m. However if the proposed substation location is less than 12m away from the main road then the sikka can be accepted with minimum clear width of 3.05 m.

2-4) Must have minimum two-side ventilation with aluminum louver doors and fixed

aluminum louvers window. Fixed aluminum louver window(s) should be located at 0.30m above outside level.

2-5) Cable arrangement:

a) In case of cable trench arrangement, clear depth of 0.95m from FFL (finished floor

level) of the Substation is to be provided.

b) In case of cable tray arrangement, clear depth of 0.95m from FFL of the substation up to bed of the cable tray with minimum clearance of 0.45m is to be maintained in between bottom of the slab and the bed of the cable tray. For cable maintenance minimum of 1.2m free space is to be provided towards of the cable tray (at least one side). The cable tray should pass through public/open area and not through any closed area / room (there shall be no services, pipes, etc, below the cable tray).

2-6) Opening of 0.95m depth from outside level (towards road/sikka) should be provided for

HV cable entry (subject to DEWA design).

2-7) Finish Floor Level (FFL) of the substation is to be maintained 0.15m to 0.30m higher than the outside adjacent ground level (towards door side).

2-8) LV electrical room should be adjacent/near to the substation, if main panel is private

(as per circular for LV room attached Annex-4). Separate approval for location and size of LV room to be obtained from Consumer Services Department.

2-9) Wet areas (i.e. kitchen, bath, toilet etc.) above substation are not acceptable. Only in

exceptional unavoidable cases, this may be accepted at the discretion of DEWA subject to complying with the following: -

a) Annexure-1 (Regulation for wet area). b) Annexure-2 (Guarantee letter). c) Annexure-3 (Checklist to be filled and signed by consultant/contractor). d) Substation clear height is to be maintained no less than 3.66m from substation

FFL up to the bottom of the attic slab.

2-10) Chillers/Motors Loads:

a) For Chillers/Motors with capacities more than (100kW), follow the Circular of Chiller/Motor loads proposed to be connected to DEWA Transformer [as per Annex-5].

b) For Chillers/Motors with capacities between [50kW – 100kW], The total

connected load should not exceed the following:

b-1) 650kW from 1000kVA. b-2) 950kW from 1500kVA.

c) For No Chiller/Motor available: -

c-1) Conformation note is to be mentioned on Load Summary Sheet.

3) Proposal should be submitted along with the following Documents /Details:

3-1) Copy of full set of valid DEWA Building NOC. 3-2) One copy of valid affection /site plan issued by DM or any competent authority.

3-3) One copy of site setting out plan showing the location & size of the proposed and

existing (if any) substation(s).

3-4) Three copies of Architectural plan drawing indicating the location & size of the proposed substation(s) in Ground Floor (existing substation(s) to be shown also, if any) and LV Room.

3-5) One copy of Above-Ground Floor Plan drawing.

3-6) One copy of Basement floor plan drawing (if applicable).

3-7) One copy of Substation Room details drawing plan showing sections (x-x & y-y). LV

route and LV opening are to be indicated.

3-8) One copy of Load Summary Sheet indicating Total Connected Load (TCL), Max Demand (MD) and KWH metering for each transformer along with a realistic Power Requirement Date.

3-9) Chiller/Load checklist to be duly filled and submitted by the consultant, if applicable

(refer to Annex- 6). 3-10) One copy of Schematic Diagram showing load intake & metering arrangement.

General Conditions / Requirements for Approval of Location & Size of Split Room Substation(s) –

RMU & Transformer Rooms in Ground Floor within Building (only Dedicated) 1. Area Requirement:

1-1. Transformer Room (Basement Floor)

a) 21m2 for 1x1000/1500 kVA transformer (with minimum width of 4.57m towards door

side) b) 42m2 for 2 x1000/1500 KVA transformers (with minimum width of 6.1m towards door

side)

(For every additional transformer, approximately 21m additional space is required)

1-2. RMU Room (Ground Floor)

a) 9.3m2 area (with minimum width of 3.05mtrs towards door side) for one set of RMU (controlling up to two transformers)

(For each additional RMU set, approximately 7m2 additional space** is required)

** For S/S having more than four Transformers an additional space of (10 m2) shall be required with minimum width of 5m towards roadside]

2. Conditions for RMU room:

2-1) Clear height – 3.05m (minimum).

2-2) Directly located on RTA/Public Road or Sikka.

2-3) In case RMU room is located on Sikka, the sikka should have a minimum clear width of

6.1m. However if the proposed RMU room location is less than 12m away from the main road then the sikka can be accepted with minimum clear width of 3.05 m.

2-4) Opening of 0.95 m depth from outside level (towards road/sikka) should be provided

for HV cable entry (subject to DEWA design). 2-5) Level difference (FFL) of the RMU room is to be maintained 0.15m to 0.30m higher

than the outside adjacent ground level.(towards door side). 2-6) RMU room aluminum louver door(s) clear height - 2.75m (ht) & clear width – 2.44m

(W) as per door details ref. drawing nos. P-DS/DOOR/01/96 (Rev.’A’) and P-DS/DOOR/02/96 (as per Annex-7 ). The RMU room must have minimum one side ventilation through the louvered door in any case.

2-7) Cable arrangement: a) In case of cable trench arrangement, clear depth of 0.95m from FFL (finished floor

level) of the Substation is to be provided.

b) In case of cable tray arrangement, clear depth of 0.95m from FFL of the substation up to bed of the cable tray with minimum clearance of 0.45mtrs is to be maintained in between bottom of the slab and the bed of the cable tray. For cable maintenance minimum of 1.2m free spaces is to be provided towards of the cable tray (at least one side). The cable tray should pass through public/open area and not through any closed area / room (there shall be no services, pipes, etc, below the cable tray).

3. Conditions for Transformer room:

3-1) Clear direct unhindered access (of minimum 3.05m width & minimum 3.05m clear height) from RTA/Public road or sikka.

3-2) Clear height – 3.66m (minimum).

3-3) Must have minimum two-side ventilation with aluminum louver doors and fixed

aluminum louvers window. Fixed aluminum louver window(s) should be located at 0.30 m above out side level.

3-4) Transformer Room aluminum louver door(s) clear height – 2.75m & clear width – 3.05m

(2.44m in exceptional cases) as per door details ref. drawing nos. P-DS/DOOR/01/96 (Rev.’A’) and P-DS/DOOR/02/96 (as per Annex-7).

3-5) Finish Floor Level (FFL) of the transformer room is to be maintained 0.15m to 0.30m

higher than the outside adjacent ground level (towards door side).

3-6) Cable arrangement: a) In case of cable trench arrangement, clear depth of 0.50m from FFL (finished floor

level) of the Substation is to be provided. b) In case of cable tray arrangement, minimum clear depth of 0.5m from FFL of the

substation up to bed of the cable tray with minimum clearance of 0.45m is to be maintained in between bottom of the slab and the bed of the cable tray. For cable maintenance minimum of 1.2m free space is to be provided towards of the cable tray (at least one side). The cable tray should pass through public/open area and not through any closed area / room (there shall be no services, pipes, etc, below the cable tray).

4. Common Conditions

4-1) Transportation of Transformer(s) from the main road up to and from the transformer room is Owner’s responsibility

4-2) Cable route between RMU and transformer room:

a) In case of cable trench arrangement, clear depth of 0.95m is to be provided. If

cables pass below traffic areas, trench with RCC removable slab as per DEWA section T-T (refer to Annex-8) is to be used. If cables are not passing through traffic area, buried cables or cable ducts along with manholes at both ends (for road crossing) are to be proposed and is subject to DEWA approval (refer to Annex-11).

b) In case of cable tray arrangement, clear depth of 0.95m from FFL of the substation

up to bed of the cable tray with minimum clearance of 0.45m is to be maintained in between bottom of the slab and the bed of the cable tray. For cable maintenance minimum of 1.2m free space is to be provided towards of the cable tray (at least one side). The cable tray should pass through public/open area and not through any closed area / room (there shall be no services, pipes, etc, below the cable tray).

c) The cable route from RMU room in ground floor to transformer room (at basement)

is preferred to be straight (Without turns / bends); in case of bending the bending radius to be considered R = 0.95m.

4-3) Wet areas (i.e. kitchen, bath, toilet etc.) above substation are not acceptable. Only

in exceptional unavoidable cases, this may be accepted at the discretion of DEWA subject to complying with the following:-

a) Annexure-1(Regulation for wet area) b) Annexure-2 (Guarantee letter) c) Annexure-3(Checklist to be filled and signed by consultant/contractor) d) Substation clear height is to be maintained no less than 3.66m from

substation FFL up to bottom of the attic slab.

4-4) LV electrical room should be adjacent/near to the substation, if main panel is private (as per circular for LV room attached Annex-4). Separate approval for location and size of LV room to be obtained from Consumer Services Department.


a) For Chillers/Motors with capacities more than (100kW), follow the Circular of

Chiller/Motor loads proposed to be connected to DEWA Transformer [as per Annex-5)

b) For Chillers/Motors with capacities between [50kW – 100kW], The total

connected load should not exceed the following:


c) For No Chiller/Motors available:-


5. Proposal should be submitted along with the following Documents /Details:

5-1) Copy of full set of valid DEWA Building NOC.

5-2) One copy of valid affection /site plan issued by DM or any competent authority. 5-3) One copy of site setting out plan, showing the location & size of the proposed

and existing (if any) substation(s). 5-4) Three copies of Architectural plan drawing indicating the location & size of the

proposed RMU and Transformer rooms in Ground Floor (existing substation(s) to be shown also, if any) and LV room.

5-5) One copy of Above-Ground Floor Plan drawing. 5-6) One copy of Basement Floor Plan drawing (if applicable). 5-7) One copy of RMU & Transformer Room details drawing plan showing sections (x-x

& y-y). LV route and LV opening are to be indicated. 5-8) One copy of Load Summary Sheet indicating Total Connected Load (TCL), Max

Demand (MD) and KWH metering for each transformer along with a realistic Power Requirement Date.

5-9) Chiller/Load checklist to be duly filled and submitted by the consultant (refer to

Anex- 6)

5-10) One copy of Schematic Diagram showing load intake & metering arrangement.

5-11) One copy of Architectural plan indicating HV cable route between RMU

room & Transformer room, along with its sectional details showing the typical horizontal/vertical clearances available for the route.

5-12) Undertakings in prescribed form duly signed by the owner of the plot

(officially stamped if owner is a company) for Ground Floor Split Substation (refer to Anex-10). Signature should match the owner’s passport copy. In case owner is a company, undertaking letter should show the company’s official stamp.

General Conditions/Requirements for Approval of Location & Size of Split-room Substation(s) -

RMU in Ground Floor & Transformer Room in Basement Floor (only Dedicated) (Subject to special requirements)

1. Area Requirement:

1-1. Transformer Room (Basement Floor):

a) 21m2 for 1x1000/1500 kVA transformer (with minimum width of 4.57m towards door

side)

b) 42m2 for 2 x1000/1500 KVA transformers (with minimum width of 6.1m towards door side)

(For every additional transformer, approximately 21m2 additional space is required)

1-2. RMU Room (Ground Floor):

a) 9.3m2 area (with minimum width of 3.05mtrs towards door side) for one set of RMU (controlling up to two transformers)

(For each additional RMU set, approximately 7m2 additional space** is required)

** For S/S having more than four Transformers an additional space of (10 m2) shall be required with minimum width of 5m towards roadside]

2. Conditions for RMU room:

2-1) Clear height – 3.05m (minimum) 2-2) Directly located on RTA/Public Road or Sikka. 2-3) In case RMU room is located on Sikka, the sikka should have a minimum clear width of

6.1m. However if the proposed RMU room location is less than 12m away from the main road then the sikka can be accepted with minimum clear width of 3.05 m.

2-4) Opening of 0.95 m depth from outside level (towards road/sikka) should be provided

for HV cable entry (subject to DEWA design). 2-5) Level difference (FFL) of the RMU room is to be maintained 0.15m to 0.30m higher

than the outside adjacent ground level (towards door side). 2-6) RMU room aluminum louver door(s) clear height - 2.75m (ht) & clear width – 2.44m

(W) as per door details ref. drawing nos. P-DS/DOOR/01/96 (Rev.’A’) and P-DS/DOOR/02/96 (as per Annex-7 ). The RMU room must have minimum one side ventilation through the louvered door in any case.



level) of the Substation is to be provided. b) In case of cable tray arrangement, clear depth of 0.95m from FFL of the substation

up to bed of the cable tray with minimum clearance of 0.45mtrs is to be maintained in between bottom of the slab and the bed of the cable tray. For cable maintenance minimum of 1.2m free space is to be provided towards of the cable tray (at least one side). The cable tray should pass through public/open area and not through any closed area / room (there shall be no services, pipes, etc, below the cable tray.

3. Conditions for Transformer room:

3-1) Clear direct unhindered access (of minimum 3.05m width & minimum 3.05m clear height) from RTA/Public road or sikka.

3-2) Clear height – 3.05m (minimum) 3-3) Must have minimum two sides ventilation with aluminum louver doors and fixed

aluminum louvers window. Fixed aluminum louver window(s) should be located at 0.3m above outside level.

[Total minimum Grill area is 14.9 m2 for 1000kVA transformer and 18.6m2 for 1500kVA transformer (as per DEWA Drg. No. PTD/MESH/01/02)](refer to Annex-11). **If two and more transformers are proposed, then calculations supporting the adequacy of natural ventilation for maintaining the ambient temperature inside substation at maximum 55 degree centigrade, based on outside air ambient temperature of 48 degree centigrade to be furnished (refer to Annex- 12). Otherwise, forced ventilation is to be proposed along with calculation.

3-4) Level difference (FFL) of the transformer room is to be maintained 0.075m to 0.15m

higher than the outside adjacent ground level (towards door side).

3-5) Transformer room aluminum louver door(s) clear height – 2.75m & clear width – 3.05m (2.44m in exceptional cases) as per door details ref. drawing nos. P-DS/DOOR/01/96 (Rev.’A’) and P-DS/DOOR/02/96 (as per Annex-7).



level) of the Substation is to be provided. b) In case of cable tray arrangement, clear depth of 0.95m from FFL of the substation


3-7) Transportation of Equipments in transformer room:

a) In case of transportation through ramp:

a-1) The ramp up to the transformer room should be straight with 3.05m (minimum) width and clear height from main road up to the transformer room.

a-2) Slope of the ramp to be maintained 1:10 (10%) (Maximum) and should be straight without sloped curves and speed breakers (bumps).

b) In case of transportation through slab cut out opening:

b-1) The cut out size to be 3 m x 3 m and to be adjacent to the main RTA/Public

roadside. b-2) The area below the cut out at basement must be designated as loading /

unloading bay. b-3) The area above the cut out is to be open to sky. If above-floor exists, then the

clear height is to be maintained 7m (for the boom of the crane to transport the transformer, etc.).

b-4) If the cut out slab is directly located above the transformer room, then the slab cut out cover is to be weather proof type with removable covering arrangement.

4. Common Conditions

4-1) Transportation of Transformer(s) from the main road up to and from the transformer

room is Owner’s responsibility 4-2) Cable route between RMU and transformer room:

a) In case of cable tray arrangement, clear depth of 0.95m from FFL of the substation


b) The cable route from RMU room in ground floor to transformer room (at basement)

is preferred to be straight (Without turns / bends); in case of bending the bending radius to be considered R = 0.95m.

4-3) Wet areas (i.e. kitchen, bath, toilet etc.) above substation are not acceptable. Only

in exceptional unavoidable cases, this may be accepted at the discretion of DEWA subject to complying with the following:-

a) Annexure-1 (Regulation for wet area) b) Anexexure-2 (Guarantee letter) c) Annexure-3 (Checklist to be filled and signed by consultant/contractor) d) Substation clear height is to be maintained no less than 3.66m from substation FFL

up to bottom of the attic slab.

4-6) LV electrical room should be adjacent/near to the substation, if main panel is private (as per circular for LV room attached Annex-4). Separate approval for location and size of LV room to be obtained from Consumer Services Department.


a) For Chillers/Motors with capacities more than (100kW), follow the Circular of

Chiller/Motor loads proposed to be connected to DEWA Transformer [as per Annex-5].

b) For Chillers/Motors with capacities between [50kW – 100kW] The total connected

load should not exceed the following:






5-2) One copy of valid affection /site plan issued by DM or any competent authority 5-3) One copy of site setting out plan, showing the location & size of the proposed

and existing (if any) substation(s). 5-4) Three copies of Architectural plan drawing indicating the location & size of the

proposed RMU room in Ground Floor (existing substation(s) to be shown also, if any).

5-5) Three copies of Architectural plan drawing indicating the location & size of the proposed transformer room in Basement Floor (existing substation(s) to be shown also, if any).

5-6) One copy of Above-Ground Floor Plan drawing. 5-7) One copy of Below-Basement Floor Plan drawing (if applicable). 5-8) One copy of RMU & Transformer Room details drawing plan showing sections (x-x

& y-y). LV route and LV opening are to be indicated.

5-9) One copy of sectional details for Ramp showing the access width and height from the ramp up to transformer room in basement floor (if applicable).

5-10) One copy of Load Summary Sheet indicating Total Connected Load (TCL),

Max Demand (MD) and KWH metering for each transformer along with a realistic Power Requirement Date.

5-11) One copy of Schematic Diagram showing load intake & metering

arrangement.

5-12) One copy of Architectural plan indicating HV cable route between RMU room & Transformer room, along with its sectional details showing the typical horizontal/vertical clearances available for the route and indicating the entry/turning points details.

5-13) Undertakings in prescribed form duly signed by the owner of the plot for

Basement Floor Split Substation (refer to Anex-13). Signature should match the owner’s passport copy. In case owner is a company, undertaking letter should show the company’s official stamp.

5-14) Method statement of transportation of transformer(s) to and from the

Transformer Room.

General Conditions / Requirements for Approval of Location & Size of Substation(s)

(Regular) Outside Building (Open to sky Plot) - only Dedicated

1. Area Requirement:

1-1. Substation Location (Outside Building)

a) 6.1m X 6.1m (Open to sky) for 1X1000/1500KVA and 1xRMU {Substation with extra large kiosk}

b) LV Room must be adjacent to the substation space

2. Area/space conditions:

2-1) Directly located on RTA/Public Road or Sikka. 2-2) In case substation is located on Sikka, the sikka should have a minimum clear width of


2-3) The height of the compound wall around the substation should not be more than

2.13m (7ft) 2-4) Soak-away should be 3.66m (minimum) away from the substation. 2-5) Substation space should be open to sky (to be mentioned).

2-6) LV electrical room should be adjacent/near to the substation, if main panel is private

(as per circular for LV room attached Annex-4). Separate approval for location and size of LV room to be obtained from Consumer Services Department.


a) For Chillers/Motors with capacities more than (100kW) follow the Circular of

Chiller/Motor loads proposed to be connected to DEWA Transformer [refer to Annex-5].

b) For Chillers/Motors with capacities between [50kW – 100kW] The total connected

load should not exceed the following:






3-2) One copy of valid affection /site plan issued by DM or any competent authority 3-3) Three copies of site setting out plan, showing the location & size of the proposed and

existing (if any) substation(s) and LV room. 3-4) One copy of Load Summary Sheet indicating Total Connected Load (TCL), Max


3-5) One copy of Schematic Diagram showing load intake & metering arrangement.

General Conditions / Requirements for Approval of Location & Size of Pocket Substation

outside Building (Open to sky) – Shared/Dedicated

1.Area Requirement:

1-1) 4.57m X 3.66m (Open to sky) for 1 x 1000/500KVA. 1-2) 6.1m X 6.1m (Open to sky) for 2 x 1000/500KVA.

2.Area/space conditions: 2-1) Directly located on RTA/Public Road or Sikka.

2-2) In case substation is located on sikka, the sikka should have a minimum clear width of


2-3) Substation’s side of size 4.57m or 6.1m should be along the RTA/Public road or sikka. 2-4) The height of the compound wall around the substation should not be more than

2.13m (7ft) 2-5) Soak-away should be 3.66m (minimum) away from the substation. 2-6) Substation space should be open to sky (to be mentioned). 2-7) Substation is suitable for releasing supply through individual feeders, each of 400A

(maximum rating).

3.Proposal should be submitted along with the following Documents /Details:

3-1) Copy of full set of valid DEWA Building NOC. 3-2) One copy of valid affection /site plan issued by DM or any competent authority 3-3) Three copies of site setting out plan, showing the location & size of the proposed and

existing (if any) substation(s). 3-4) One copy of Load Summary Sheet indicating Total Connected Load (TCL), Max


3-5) One copy of Schematic Diagram showing load intake & metering arrangement. 3-6) Location confirmation form (If applicable) to be signed by the Consultant /

Contractor [Annex-15]

3-7) Undertakings in prescribed form duly signed by the owner of the plot for shared substation [refer to Annex-14]. Signature should match the owner’s passport copy. In case owner is a company, undertaking letter should show the company’s official stamp.

General Conditions / Requirements for Approval of Location & Size of Temporary pocket substation Outside Building (Open to sky) Plot

1.Area Requirement: 1-1) 4.57m X 3.66m (Open to sky) for 1 x 1000/500KVA 1-2) 6.1m X 6.1m (Open to sky) for 2 x 1000/500KVA

2.Area/space conditions:

2-1) Directly located on RTA/Public Road or Sikka.

2-2) In case substation is located on sikka, the sikka should have a minimum clear width of


2-3) Substation’s side of size 4.57m or 6.1m should be along the RTA/Public road or sikka. 2-4) If the proposed location of the substation is outside your plot limit, approval to be

obtained from the owner of the plot where the substation is proposed or Dubai Municipality/Competent Authority (in case if the location lies in Dubai Municipality/ competent Authority area).

2-5) Soak-away to be 3.66m (minimum) away from the substation. 2-6) Substation space should be open to sky (to be mentioned). 2-7) Substation is suitable for releasing supply through individual feeders, each of 400A

(maximum rating).

3.Proposal should be submitted along with the following Documents /Details:

3-1) Copy of full set of valid DEWA Building NOC (exclusively issued for temporary supply only).

3-2) One copy of valid affection /site plan issued by DM or any competent authority 3-3) Two copies of site setting out plan, showing the location & size of the proposed and

existing (if any) substation(s). 3-4) One copy of Load Summary Sheet indicating Total Connected Load (TCL), Max

Demand (MD) and KWH metering for each transformer. 3-5) One copy of Schematic Diagram showing load intake & metering arrangement. 3-6) Date of power requirement and the duration of the temporary supply requirement.

General Conditions/Requirements for Providing Direct 6.6/11/22 KV Supply to Consumer’s Plot (substation owned & maintained by consumer)

[Only for Industrial / Private Load - Subject to DEWA Approval]

PART-I Proposal should be submitted along with the following documents for approval of private equipments substation.

1. Copy of DEWA Building NOC along with affection / site plan from DM/Competent

2. Copy (3 Nos.) of setting out plan indicating DEWA Control/Metering room. Party’s circuit Breaker room should be adjacent to Metering/Control room.

3. Soft copy of setting out plan in Microstation (J) with DLTM coordinates. 4. Copy of Control/Metering room layout drawings details plan to be shown through

horizontal & vertical sectional views. For Control/Metering room size requirements (refer to Annex-22).

5. Copy (4 Nos.) of single line diagram (schematic) showing load intake arrangement

with details of protection scheme as following: -

a) CT & VT rating, Burden, Class etc. b) Details of O/C & E/F relay.

c) Bus section details along with Interlocking arrangement for more than 1 feeder

d) TCL & MD for each feeder.

e) TCL & MD for each Transformer, motor etc.

f) Metering arrangement

g) Details of Power Transformer (Type, Rating, Ratio, % Imp, etc)

h) Starting current of motors & the motor details (if applicable)

i) All earthing points

j) DEWA point of supply & ownership boundary.

k) Please refer to Protection guidelines (Annex-19)

6. Copy of load schedule including TCL & maximum demand load with kWh Meter

(metering arrangement at DEWA ‘s Meter/Control room). 7. A checklist for the protection scheme is to be filled and signed by consultant (refer

to Annex-20). Also a guideline attached for the reference of the same (Annex-19).

8. You are requested to obtain written acceptance from the owner of the project to the effect that, maintenance/replacement of breaker, fuse switch and transformers, cables which will be procured by you shall be done by the owner in future and forward the same to us. We will require this before commencement of works for the project.

9. (a) Calculation of voltage drop & (b) Harmonics at DEWA source ensuring that these

are within limits specified by DEWA (planning voltage guideline attached Anex-19).

10. Date of power requirement.

Note: Generally, review of the above documents shall be done within one month

PART-II The following documents/information should be submitted subsequently after approval of above for energization of private equipment and release of power through private equipment.

1. Revised/updated copy of single line diagram (schematic, if applicable- 4 copies) 2. Step by step relay setting calculations. The relay co-ordination shall be made based

on maximum fault current and the grading margin shall be kept at 0.300 seconds between DEWA end to private party’s panel end.

3. Owner’s undertaking stating ‘’ Our equipment are suitable for energisation in line

with DEWA network system’’& confirm that relay’s are set as per DEWA approved settings.

4. HV cable Jointer’s list in details (approved by DEWA).

5. Names and telephone numbers of contact person for the project who should be

available 24 hours day & night. 6. Name of competent technical staff, who know the switchgear operation and

capable of issuing work permit stating that cable is safe for works and also ensure no one will operate during testing & repairing time.

7. Operation philosophy (interlocking details)[attached sample Anex-21]

8. All catalogue for CT, VT, Relay & motor to be submitted. 9. Formal application form for the supply to DEWA is to be filled and submitted to the

Consumer Services Department (CSD). 10. Payment against the estimate

11. Handing over of DEWA Meter/Control room getting it inspected and approved.

(Submitted through DEWA website)

12. You are requested to obtain written acceptance from the owner of the project to the effect that, maintenance of breaker, fuse switch and transformers, which will be procured by you shall be done by the owner in future and forward the same to us. This will be required before commencement of works for the project.

NOTE: - Please note that under normal circumstances we shall require a period of 16 weeks for commissioning the substation after the comply of all the requirement as stated in PART-III

General Conditions/Requirements for Providing Direct 6.6/11/22 KV Supply to Consumer’s Plot (substation owned & maintained by consumer)

[Only for High-rise Towers above 200m - Subject to DEWA Approval Based on Technical Justification]

PART-I

General Information and Conditions

1. Point of supply/Responsibility (Annex-16 for clear understanding).

2. Beyond DEWA point of supply all the equipments (like switchgear, transformer cable

etc.) has to be procured, installed, commissioned, operated and maintained by the

owner.

3. DEWA will not supply, operate or maintain any equipment to be installed above

ground level.

4. All equipment (Circuit Breaker, Transformer etc) procured by party should be dual

ratio (6.6/11/22 KV) unless clearly advised by DEWA that it is 11/22KV.

5. All equipments should be compliant with international standards (IEC standards)

6. Total losses of transformer should not exceed 1.5% of rated capacity due to

conservation reasons.

7. Power factor at party’s point of supply should be maintained at 0.95 or higher.

8. Party’s incomer should be Switchgear with CB, E/F & O/C protection and should be

located adjacent to DEWA’s Meter/Control room.

9. Guidelines for 11-22KV-network design should be followed (Annex-17).

10. LV distribution shall comply with DEWA guidelines and standards.

11. Only Cast Resin transformers (fire resistant transformers) will be allowed to be

installed in Residential / Commercial buildings.

Technical Justification should be submitted for availing direct 6.6/11/22 KV supply to the high-rise building for locating transformers above ground level/s. This depends on the height of the building, size of load, type of load, etc. Normally, buildings of height 200m or above shall be considered for direct 6.6/11/22 KV supply.

PART-II Proposal should be submitted along with the following documents for DEWA review.

1. Copy of DEWA Building NOC along with affection / site plan from DM/Competent.

2. Copy (3 Nos.) of setting out plan indicating DEWA Control/Metering room (soft copy

of setting out plan in Microstation (J) with DLTM coordinates). Party’s circuit Breaker

room should be adjacent to Metering/Control room.

3. Copy of Control/Metering room layout drawings details plan to be shown through

horizontal & vertical sectional views. For Control/Metering room size requirements

(refer to Annex-18).

4. Copy (4 nos.) of single line diagram (schematic) showing load intake arrangement

with details of protection scheme as following: -

a) CT & VT rating, Burden, Class etc. b) Details of O/C & E/F relay.

c) Bus section details along with Interlocking arrangement for more than 1 feeder

d) TCL & MD for each feeder.

e) TCL & MD for each Transformer, motor etc.

f) Metering arrangement

g) Details of Power Transformer (Type, Rating, Ratio, % Imp, etc)

h) Starting current of motors & the motor details (if applicable)

i) All earthing points

j) DEWA point of supply & ownership boundary.

k) Please refer to Protection guidelines (Annex-19)

5. Copy of load schedule including TCL & maximum demand load with kWh Meter,

(metering arrangement at DEWA Meter/Control room)

6. A checklist for the protection scheme is to be filled and signed by consultant (refer

to Annex-20). Also a guideline attached for the reference of the same (Annex-19).

7. You are requested to obtain written acceptance from the owner of the project to

the effect that, maintenance/replacement of breaker, fuse switch and transformers,

cables which will be procured by you shall be done by the owner in future and

forward the same to us. We will require this before commencement of works for the

project.

8. Date of power requirement.

Note: Generally, review of the above documents shall be done within one month PART-III The following documents/information should be submitted subsequently after approval of above for energization of private equipment and release of power through private equipment.

1. Revised/updated copy of single line diagram (schematic, if applicable- 4 copies) 2. (a) Calculation of voltage drop & (b) Harmonics at DEWA source ensuring that these

are within limits specified by DEWA (planning voltage guideline attached Anex-19).

3. Step by step relay setting calculations. The relay co-ordination shall be made based on maximum fault current and the grading margin shall be kept at 0.300 seconds between DEWA end to private party’s panel end.

4. Owner’s undertaking stating ‘’ Our equipment are suitable for energisation in line

with DEWA network system’’& confirm that relay’s are set as per DEWA approved settings.

5. HV cable Jointer’s list in details (approved by DEWA).

6. Names and telephone numbers of contact person for the project who should be

available 24 hours day & night.

7. Name of competent technical staff, who know the switchgear operation and capable of issuing work permit stating that cable is safe for works and also ensure no one will operate during testing & repairing time.

8. Operation philosophy (interlocking details)[attached sample Anex-21]

9. All catalogue for CT, VT, Relay & motor to be submitted.

10. Formal application form for the supply to DEWA is to be filled and submitted to the Consumer Services Department (CSD).

11. Payment against the estimate

12. Handing over of DEWA Meter/Control room getting it inspected and approved.

(Submitted through DEWA website)

13. You are requested to obtain written acceptance from the owner of the project to the effect that, maintenance of breaker, fuse switch and transformers, which will be procured by you shall be done by the owner in future and forward the same to us. This will be required before commencement of works for the project.

NOTE: - Please note that under normal circumstances we shall require a period of 16 weeks for commissioning the substation after the comply of all the requirement as stated in PART-III

General Conditions/Requirements for Approval of Wet Areas Above Substation/Ring Main Unit Room in Private Buildings In principle there shall not be any wet facilities above the substation/Ring Main Unit Room. Only in exceptional unavoidable cases this may be allowed at the discretion of the Authority and the following requirements must be fulfilled 1. A Reinforced Concrete Attic slab above the entire substation/Ring Main Unit Room shall be provided. 2. The entire attic slab and floor slab above including the vertical sides above attic slab shall be waterproofed by an approved system. 3. The consultant shall be fully responsible for supervision of the waterproofing works, during execution and testing of waterproofing. 4. All pipes, joints, traps, etc. running in wet areas shall be wrapped with approved Waterproofing membrane. No pipes shall pass through the void between floor and attic slab. 5. The void between floor and attic slab shall be minimum 60cms clear height. Access to the void above attic slab shall be 120cm x 60cm fitted with aluminum louvered door. The void shall not be used for any other purpose and shall have permanent lighting arrangement. Drain pipe to be provided for the attic slab to drain out any water leakage through floor slab. Tiles are not compulsory above attic slab. 6. The consultant shall forward complete floor plans showing location of Wet Area and Substation/Ring Main Unit Room. Extent of attic slab shall be clearly marked in the plans. Typical cross sections through the Wet Area/Substation/Ring Main Unit Room and Attic Slab shall be shown in the drawings including waterproofing arrangement/systems/materials. The drawings shall be forwarded to Dubai Electricity and Water Authority Civil Engineering Department for Wet Area Approval. 7. A guarantee letter shall be signed by the owner of the Project and witnessed/endorsed by the consultant, as per the attached format. DEWA-PTD-DS-IA-WET AREA APPROVAL_IN_BLDG-R0 16-09-2002

To: M/s. Dubai Electricity & Water Authority Date: ___________ P.O. Box 564, DUBAI, Dear Sirs,

SUB: GUARNTEE AGAINST DAMAGES DUE TO WATER LEAKAGES IN DEWA’S ELECTRICAL SUBSTATION ROOM,

Building in which the substation __________________________________________ is located: Location: __________________________________________ Full Name & Address of the owner: __________________________________________ __________________________________________ __________________________________________ We hereby undertake that we are fully responsible for any leakages due to any defect in the waterproofing system and/or construction method adopted, and in such an event we shall immediately repair the leakages at our cost. We also undertake that if any damages are caused to DEWA’s equipments due to the leakages and/or while any repair works are carried out we shall compensate such damages, failing which DEWA reserves the right to take any appropriate measures deemed fit. BUILDING OWNERS’S SIGNATURE:__________________________________________ TEL. NO.: __________________________________________ DATE: __________________________________________ WITNESSED BY: CONSULTANT: __________________________________________ SIGNATURE & STAMP: __________________________________________ TEL. NO. : __________________________________________

Wet area above substation/ring main unit in private buildings Plot No.__________________________ Area.____________________________ S.No Description Remarks Tick 1 Reinforced concrete attic slab above entire substation/ring

main unit

2 A clear depth (void) of 600mm between attic slab and floor slab.

3 An access aluminum lowered door of 1200x600mm to above clear depth (void) from outside substation

4 Water proofing of attic slab , floor slab above attic slab and

vertical side walls

5 Drain pipe of 1.5” projecting out of the attic slab 6 Screed in slope towards drain 7 Water proofing of All pipe joints, traps etc running in wet

areas

8 Lighting inside the void space 9 Drawings showing the above details attached 10 Guarantee letter 11 Any deviation of above Submission should be duly filled and signed with tick mark is must. Name of Consultant/Consultant Seal Signature of authorized person

Chiller / Motor Loads Proposed to be Connected to DEWA Transformer

1. All Chillers above 100 kW power requirement proposed to be connected to LV supply have multi stage compressors and designed for sequential start with time delay of 1 to 3 minutes.

2. Following guideline is to be considered at the design stage, to include Chiller / Motor Loads, for connection to DEWA transformer through Private LV Panels.

No.

Description 1000 kVA Transformer Confirmed (√ Tick)

1500 kVA Transformer Confirmed (√ Tick)

1 Maximum Total Connected Load

permitted (Diversity Factor = 1.0)

650 kW 950 kW

2 Maximum permissible Starting

Current of each compressor /

motor

400 A (Higher values may be permitted subject to submission of specific

justifications)

540 A (Higher values may be permitted subject to submission of specific

justifications)

3 Sequential start of chillers /

compressors

Only one compressor shall start at one time with a time delay of 1

to 3 minutes

Only one compressor shall start at one time with a time delay of 1

to 3 minutes

4 Requirement of starters

Soft starters / or similar type to limit starting

current as indicated in Item 2 above

Soft starters / or similar type to limit starting

current as indicated in Item 2 above

I confirm that all Chillers above 100 kW power requirement is to be connected to LV supply having multi stage compressors and designed for sequential start with time delay of 1 to 3 minutes.

I confirm that permissible Voltage Flicker limits, frequency of starting of the chillers, etc, is considered to ensure the safety of the consumers’ equipment, installations and quality of supply, in the respective project(s).

Signature of Authorized Person & Official Seal Consultant Contact Information: Tel No.:_______________________ Fax No.:_______________________ Mob No.:______________________ Address:_______________________

Pagge 1 of 2

Pagge 2 of 2

UNDERTAKING

(Ground Floor Split Substation) To Dubai Electricity & Water Authority P.O. Box 564 DUBAI Dear Sirs, Sub: Electric Supply to my Residential/Commercial Building on Plot No._______________ at_______________ I, ____________________________ (full address given under) the owner of the above building agree to the following conditions: 1. I shall be fully responsible for transportation of transformers and other equipment from

DEWA’s truck and placing it on the foundations in the substation room (or vice versa), as required by DEWA.

2. I shall arrange adequate insurance to cover the damage to DEWA equipment while handling by

our personnel as mentioned in (1) above. [The cost of one transformer is Dhs.110, 000/- (approx.) and weight is about 6.5 Ton].

3. I shall not modify any parts of the building that affect the access to DEWA equipments. I shall

not make any alteration / modification in substation without the prior approval of DEWA. 4. DEWA will not be held responsible for any delay in restoring power caused due to non-

availability of the equipment transportation arrangement. The responsibility for such delay will be mine.

5. My contact address/telephone number (of an authorized representative) will always be available

at the project site. 6. In the event that I transfer or lease the property to any other party, the above conditions will be

made known to that party. 8. All future maintenance of substation (civil works) including repairs / replacement of the door will

be carried out by me. ------------------- Signature Name: _______________ P.O. Box. ______________ Telephone No. _______________ Telefax No. _______________ Place: Contact Person Name: _______________ P.O. Box _______________ Telephone No. _______________ Telefax No. _______________ NK:IA/08.04.02

NB: Owner’s Passport Copy To Be Attached يرفق صورة جواز سفر المالك

UNDERTAKING Transformer Room in Basement

To Dubai Electricity & Water Authority P.O. Box 564 DUBAI Dear Sirs, Sub: Electric Supply to my Residential/Commercial Building on Plot No._________________ at______________. I, ____________________________ (full address given under) the owner of the above building agree to the following conditions: 1. I shall be fully responsible for transportation of transformers and other equipment from DEWA’s truck and placing it on the foundations in the substation at the basement (or vice versa), as required by DEWA. 2. When RMU is located in the ground floor, I shall make the arrangement to lay the HV cable from the transformer located at the basement to the RMU in the ground floor. Facility for supporting the cables will be provided through out the HV cable route and we shall not allow any other services underneath. 3. I shall make the arrangement to lay the LV single core cable from the transformer located at the basement to our LVDBs in the LV room and we shall terminate those cables in our LVDB’s end. 4. In the eventuality of cable fault, I shall make arrangement similar to that provided at the time of initial installation as given in (2 and 3) above. 5. I shall arrange adequate insurance to cover the damage to DEWA equipment while handling by our personnel as mentioned in (1) above. [The cost of one transformer is Dhs.110, 000/- (approx.) and weight is about 6.5 Ton]. 6. I shall not modify any parts of the building that affect the access to DEWA equipments. I shall not make any alteration / modification in substation without the prior approval of DEWA. 7. DEWA will not be held responsible for any delay in restoring power caused due to non-availability of the equipment transportation arrangement. The responsibility for such delay will be mine. 8. My contact address/telephone number (of an authorized representative) will always be available at the project site. 9. In the event that I transfer or lease the property to any other party, the above conditions will be made known to that party. 10. All future maintenance of substation including repairs / replacement of the door will be carried out by me.

------------------- Signature Name: _______________ P.O. Box. ______________ Telephone No. _______________ Telefax No. _______________ Place: Contact Person Name: _______________ P.O. Box _______________ Telephone No. _______________ Telefax No. _______________

NK:IA/08.04.02

NB: Owner’s Passport Copy To Be Attached يرفق صورة جواز سفر المالك

Undertaking ھــــدــتـع

To: Dubai Electricity & Water Authority P. O. Box 564 Dear Sirs, Subject: Electric supply to my Residential/ Commercial Building on Plot No. ……………..at…………… I, ……………………………………... (Full address given under) the owner of the above, building agree to the following conditions:- 1. That, I agree to provide a substation room

of size………………….for electric supply to my building on above plot.

2. That, I will not ask for any rent or any other compensation for Dubai Electricity & Water Authority for the substation room in my building/plot.

3. That, I will carry out necessary civil works for the substation at my cost.

4. That, after meeting the full power requirement of my building, Dubai Electricity & Water Authority has the right to release supply to other consumers in the area using equipment installed in the substation, for which I will extend my cooperation as and when required.

Signature ………… (Address) P. O. Box: …………………………… Telephone No.: ………………………. Telefax No.: ……………………….…. Telex No.: ……………………………. (Contact Person) Name: ………………………………... P. O. Box: ……………………………. Telephone No.: ………………………. Telefax No.: …………………………..

إلى: يكھرباء ومياه دبھيئة

دبي 564ص.ب.

تحية طيبة وبعد ....

بنايتي السكنية/ التجارية الموضوع: توصيل الكھرباء إلى رقم........................... بمنطقة على األرض

..................... أتعھد أنا ....................................................

(والموضح عنواني الكامل أدناه) بصفتــــي مالـك البنــايــة -التالية: المذكـــورة أعـــاله، أوافق على الشــروط

أوافــق عـلـى تـخـصـيـص غـرفـة بـمـسـاحـة ............. . 1

.الـمـحـطـة الـفــرعــيـة الــتـي تعـــــد البنـــايـة المقـــــامــــة عــلـى األرض المذكـــورة عالية بالكھرباء.

لـــن أطــالـــب ھـــيــئــة كــھــربــاء ومــيــاه دبــــي . 2إيـــجــار أو تـــعـــويــــض عــــن غــرفــــة بــــأي

الـمـحـطـة الـفـرعـــيــة بـــبــنــايـــتـــي/ بـاألرض الـعـائـدة لـي

3. الــقــيــام بـاألعــمــال الــمــدنــيــة لــلــمـحــطـة الـفـرعـيـة عـلى نـفـقـتـي

الـخـاصـة.

بــعـــد تــوفــــيـــر كـــافــــة احـــتــــيــاجـــات . 4بــنـــايــتــي مـــن الــطــاقـــة، فــإن لــھــيــئـــــــة كــــھـــربــاء ومـــيـاه دبـــي الـحـــق فــي إمــــداد مــســتــھــلــكــيـــن آخـــريــــن فـــي الــمــنـطـقـة

ــتــخــدام الــمـعـدات الـتي تــم بــالـكــھـربــاء بـاستــركــيـبــھـا بـالـمـحـطـة الـفـرعـيـة حـيـث سـأمــد يـد

الـعـون فـي ھـــذا الـشـأن عـنـدمـا يـكـون ذلــك مـطـلـوبـاً وبـالـكـيـفـيـة الـالزمـة.

التوقيــــــــــــــع

..................... (العنوان)

........................................ص.ب. ............. رقم الھاتف: ............................................... رقم الفاكس: ............................................... رقم التلكس: ...............................................

(الشخص الذي تتم مخاطبته)

....................................................االسم: .. ص.ب.: ................................................... ھاتف: .....................................................

فاكس: ....................................................

NB: Owner’s Passport Copy To Be Attached

يرفق صورة جواز سفر المالك

For Shared Substations

DEWA Metering /control room

Party’s HV switchgear

DEWA point of supply/responsibility.

Party’s Switchgear shall be suitable for termination of 3X240 /300sq.mm XLPE/PVC/SWA/PE Aluminium/Cu cable with heat shrinkable type cable terminations. Termination at party’s switchgear incomer has to be done by party and terminations at DEWA RMU will be done by DEWA.

Pa

age 1 of 2

(DEWA Meter/Control room)

1. Size of the Control/Metering room (DEWA RMU room) shall be approximately 5.4 x 5.4 mtrs.(29.16 sqm) for regular type RMU room made of block work and RCC slab. This is for 2 Nos. 11KV feeders

2. For additional feeder (3rd) additional space required approx 10 sqm( i.e. for each

additional panel 10 sq mtr is required). Please note that the area of the Control/Metering, shall be decided only after approving the 11kV feeder arrangement (HV SLD)

3. Control/Metering room clear height shall be 3.65 mtrs. Or 12’ .

4. Control/Metering room door clear height should be 2.75 mtrs or 9’ and clear width of

2.44 mtrs or 8’. 5. Control/Metering room must have cross ventilation (2 sides) with aluminum louvers /

doors

6. 95cm of clear depth from finished floor level (FFL) to be provided for trench and for cable entry to the Control/Metering room.

7. FFL of the Control/Metering room should be higher (15cm to 30cm) with respect to

adjacent ground level (on the other side of substation door).

8. Party’s Switchgear shall be suitable for termination of 3X240 sq.mm XLPE/PVC/SWA/PE Aluminium/Cu cable with heat shrinkable type cable terminations. Termination at party’s switchgear incomer has to be done by party and terminations at DEWA RMU will be done by DEWA.

Note : Sikka / road should have a minimum clear width of 6.1m. However if the proposed substation space is less than 12m away from the main road then the sikka should have minimum clear width of 3.05m.

Guide Lines for Protection Requirement for Private Substations 1. The designer shall provide all the necessary protection to ensure that a private

substation will not have any negative impact on the DEWA system. 2. Suitable protection and interlocking shall be provided. 3. There should be sufficient discrimination between DEWA protection and that of the

private substation so that the protection at private substation operates earlier to the DEWA protection during fault.

4. In substations with multiple switchboards, the interlock shall be extended to all the switchboards.

5. The drawings shall use ANSI standard codes for depicting protection relay functions as well as contain a legend.

6. The incomer protection relays shall comply with IEC 60255 and be supported by type test and guaranteed routine manufacture’s works test certificates. Only certificates confirming that the relay has passed the type tests needs to be submitted to DEWA.

7. The incomer should have over current and earth fault protection and these should be clearly shown on the drawing.

8. The over current relay shall operate correctly for fault currents up to 25 kA. 9. Under voltage protection shall be provided as per S8 of the DEWA Regulations for

Electrical Installations. 10. Details on the relay and current transformer shall be mentioned on the drawing. Only

the test certificate needs to be submitted to DEWA 11. The instrument transformers shall comply with IEC 60044 and be supported by type

test certificates and guaranteed routine manufacture’s works test certificates. Only certificates confirming that the current transformers have passed the type tests needs to be submitted to DEWA

12. The incomer current transformer shall be dimensioned so that the protection scheme will operate effectively for a fault current of 25 kA.

13. Mechanical and electrical interlocks shall be provided so that the incomers cannot be paralleled. Both mechanical and electrical interlocks shall be shown on the drawings.

14. Power factor correction capacitors shall be provided as required by S8 of the DEWA Regulations for Electrical Installations.

15. Motor starting currents shall be shown on the drawings. Starting currents shall be in accordance with S4.6.10 of the DEWA regulations for Electrical Installations 1997.

16. Reverse power protection shall be provided to ensure that in-feeds to faults within the DEWA 11-22 kV network are cleared within 3 seconds.

17.The developer should submit the completed checklist with the single line diagram.

Sample operation philosophy (Interlocking arrangement)

Sl.No. Condition IC-1 Bus coupler IC-2 1 Normal I O I 2 Loss of Incomer-1 O I I 3 Loss of Incomer-2 I I O

Legend: I = close, O = open, IC= Party’s incomer breaker

PART-I (Space open to sky)

1. Size of the RMU foundation shall be 6.1 X 6.1 mtrs.(37.21 sqm) with FGRP Kiosk (to be supplied by

DEWA). This is for 2 Nos. 11KV feeders. 2. For additional feeder additional space required same as above.

3. The height of the boundary wall (3 sides) around the RMU foundation substation shall be not more than 7’-0”. 4. RMU space should be directly located on DM Road / Sikka

PART-II (Building room)

9. RMU room should be directly located on DM Road / Sikka 10. Size of the RMU room shall be approximately 5.4 x 5.4 mtrs.(29.16 sqm) for regular type RMU room

made of block work and RCC slab. This is for 2 Nos. 11KV feeders 11. For additional feeder (3rd) additional space required approx 3.3 sqm( i.e. total 6.9 X 5.4 mtrs.).

4. For additional feeder(4th) additional space is required approx 8 sqm(i.e. 7.5 X 5.4 Mtrs).

5. RMU room clear height shall be 12’ (for regular type RMU room made of block work and RCC slab).

6. RMU room door clear height should be 9’ and clear width of 8’. 7. RMU room must have cross ventilation (2 sides) with aluminum louvers / doors

8. 3’-2” of clear depth from finished floor level (FFL) to be provided for trench and for cable entry to the

RMU room.

9. FFL of the RMU room should be higher (6” to 12”) with respect to adjacent ground level (on the other side of substation door).

Note : If RMU space/room is located on sikka, sikka should have a minimum clear width of 3.05 m as long as proposed substation is not more than 12m away from the main road. Otherwise, the sikka should have minimum clear width of 6.1m.

Date post:	03-Oct-2014
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