Surge Protec on Devices (SPD) and the 17th Edi on 1st Amendment of BS7671 Wiring Regula ons
Surge Protec on devices available from DEM Manufacturing (branded Roxburgh EMC) have for many years offered market leading pro‐
tec on from damage caused by high energy short dura on electrical transients. These are typically caused by nearby electrical storms
(atmospheric origins) or the switching of induc ve, capaci ve and resis ve loads (switching origin). Transients can cause a variety of
problems from equipment failure to serious electrical fires and damage to distribu on systems.
Surge Protec on Devices have historically not been covered by BS7671 Wiring Regula ons, despite the vital role they can play in pro‐
tec ng electrical and electronic equipment. However, this has now changed with the recently published first amendment implemented
1st January 2012.
BS7671 17th Edi on, Chapter 44 relates to protec on against Voltage Disturbances and Electromagne c Disturbances. Sec on 443
deals specifically with protec on against over‐voltages of atmospheric origin or due to switching. Details are given as to the types of
installa ons where the risk assessment will always lead to the result that SPD is required and other areas with lower levels of conse‐
quences where calcula ons can be used to determine the need for SPD installa on. See specifically 443.2.4.
Chapter 53 deals with protec on isola on, switching, control and monitoring with 534.2 determining specifically the selec on and
erec on of surge protec on devices. Two specific types of SPD are referred to in the regula ons as Type 2 and Type 1 dependant on
the nominal discharge currents expected and the loca on of the protec on within the system. DEM’s Surge Protec on Devices meet
BS EN 61643‐11 and DEM’s class B (DVSB series) meet Type 1 and DEM class C (DVSC series) Surge Protec on Devices meet Type 2
specifica ons as referred to in chapter 53.
BS7671 WIRING REGULATIONS
1st Amendment implemented 1st January 2012
KEY SECTIONS Chapter 44 ‐ Voltage disturbances and electromagne c disturbances ‐ Sec on 443 Protec on against over‐voltages of atmospheric origin or due to switching Chapter 53 ‐ Protec on, Isola on, Switching, Control and Monitoring ‐ Sec on 534.2 Selec on and erec on of surge protec on devices
DEM Manufacturing, Deltron Emcon House, Hargreaves Way, Sawcliffe Industrial Park, Scunthorpe, North Lincolnshire. DN15 8RF
Tel: +44 (0) 1724 273200 Email: sales@dem‐uk.com www.dem‐uk.com/roxburgh
Contact our Technical Sales team on +44 (0) 1724 273216
We will be happy to answer any ques ons or help with product selec on
17th Edi on 1st Amendment Surge Protec on Devices
Roxburgh Item System Supply Appendix 16 Diagram Type1/Type2
DVSC400454TNS TT connec on Type 1 3 Phase + Neutral 16A2 Type 2
DVSC400454TT TT connec on Type 2 3 Phase + Neutral 16A3 Type 2
DVSC400453TNC IT 3 Phase 16A4 Type 2
DVSB400654TNS TN‐C‐S 3 Phase + Neutral 16A5 Type 1
DVSC400454TNS TN‐C‐S 3 Phase + Neutral 16A5 Type 2
DVSC275452TNS TN‐C‐S Single Phase 16A5 Type 2
I ProtectiveConductor
N
L3L2L1
6N
1
4a
4b
2
5
SPDSPDSPDSPD3
Distribution board1.Main earthing terminals or bar2.Surge protective devices ensuring a protection 3.level in accordance with overvoltage Category II Earthing connection of surge protective devices, 4.either 4a or 4b, whichever is the shorter routeCurrent-using equipment5.Residual current protective device (RCD)6.
OCPD 1: Overcurrent protective device at the origin of the installationOCPD 2: Overcurrent protective device
DVSC400454TNS Surge Protection Device recommended for use with TT systems, connection Type 1 (CT 1)SPD connected to the load side of an RCD according to regulation 534.2.5(i)
3 :
>125A gL
125A gLMin. recommendedcross section 6mm²
OCPD 2
OCPD 1
Last Update
04/04/2012
10/04/2012
DVSC400454TNS01
Tel No. +44(0)1724 273216 email: [email protected] Website www.dem-uk.com
DEM Manufacturing, Deltron Emcon HouseHargreaves Way, Sawcliffe Ind. Park,
Scunthorpe, North Lincolnshire, DN15 8RF, UK ISSUE NUMBER
Part No:
I
ProtectiveConductor
N
L3L2
L1
6N
1
4a
4b
2
5
SPDSPDSPD3
Distribution board1.Main earthing terminals or bar2.Surge protective devices3.
Earthing connection of surge protective devices, 4.either 4a or 4b, whichever is the shorter routeCurrent-using equipment5.Residual current protective device (RCD) installed 6.downstream of the surge protective devices
OCPD 1: Overcurrent protective device at the origin of the installationOCPD 2: Overcurrent protective device
3:
>125A gL
125A gLMin. recommendedcross section 6mm²
OCPD 2
OCPD 1
3a
Surge Protection Device recommended for use with TT systems connection type 2 (CT2) SPD connected to the load side of an RCD according to regulation 534.2.5(ii)
3a. Surge protective devices (SPDs 3 and 3a in series ensuring a protection level in accordance with overvoltage Category II.
Last Update
10/04/2012
24/04/2012
DVSC400454TT01
Tel No. +44(0)1724 273216 email: [email protected] Website www.dem-uk.com
DEM Manufacturing, Deltron Emcon HouseHargreaves Way, Sawcliffe Ind. Park,
Scunthorpe, North Lincolnshire, DN15 8RF, UK ISSUE NUMBER
Part No:
I ProtectiveConductor
L3L2L1
6
1
4a
4b
2
5
SPDSPDSPD3
Distribution board1.Main earthing terminals or bar2.Surge protective devices ensuring a protection level in 3.accordance with overvoltage Category II Earthing connection of surge protective devices, 4.either 4a or 4b, whichever is the shorter routeCurrent-using equipment5.Residual current protective device (RCD)6.
OCPD 1: Overcurrent protective device at the origin of the installationOCPD 2: Overcurrent protective device
>125A gL
125A gLMin. recommendedcross section 6mm²
OCPD 2
OCPD 1
z
Surge Protection Device recommended for use with IT systems
Last Update
10/04/2012
24/04/2012
DVSC400453TNC01
Tel No. +44(0)1724 273216 email: [email protected] Website www.dem-uk.com
DEM Manufacturing, Deltron Emcon HouseHargreaves Way, Sawcliffe Ind. Park,
Scunthorpe, North Lincolnshire, DN15 8RF, UK ISSUE NUMBER
Part No:
Source See note 4
See note 5
SPB
SPB
SPB
SPB
SPB
SPB
SPB
SPB
SPB
SPB
Installation
OCPD 2OCPD 3
4
5
3
6
PEN
OCPD 1OCPD 4
919
2
87
L1
L2
L3
N
PE
Distributionboard1.Distributionoutlet2.Mainearthingterminalorbar3.Surgeprotectivedevice,DVSB400654TNS(Type1)4.Earthingconnection(earthingconductor)ofsurgeprotectivedevice5.fixedequipmenttobeprotected6.Surgeprotectivedevice,DVSC400454TNS(Type2)7.Surgeprotectivedevice,DVSC275452TNS(Type2orType3)8.Decouplingelementorlinelength9.
NOTE 1: for further information reference should be made to CLC/TS61643-12NOTE 2: SPDs 4 & 7 (or 7 & 8) can be combined in a single SPDNOTE 3: SPDs may require additional modes of protection for sensitive equipmentNOTE 4: BS EN 62305-4 covers the protection of electrical and electronic systems within structures against lightning.NOTE 5: Section 443 of BS 7671 deals with the protection of electrical installations against transient overvoltages of atmospheric origin, transmitted by the supply distribution system and against switching overvoltages generated by the equipment within the installation
Installation of types 1, 2 and 3 SPDs for example in TN-C-S systems
4 : 7 : 8:
Last Update
10/04/2012
24/04/2012
TN-C-S SYSTEMS01
Tel No. +44(0)1724 273216 email: [email protected] Website www.dem-uk.com
DEM Manufacturing, Deltron Emcon HouseHargreaves Way, Sawcliffe Ind. Park,
Scunthorpe, North Lincolnshire, DN15 8RF, UK ISSUE NUMBER
Part No:
Part No:
ISSUE NUMBER
Tel No. +44(0)1724 273216 email: [email protected] Website www.dem-uk.com
DEM Manufacturing, Deltron Emcon HouseHargreaves Way, Sawcliffe Ind. Park,
Scunthorpe, North Lincolnshire, DN15 8RF, UK 01
TN-C-S SYSTEMS