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Sectionalizing Rick Seeling Introduction Philosophy Pete Malamen Three Phase Reclosers High-Side Protection Specific Applications
Sectionalizing
Rick SeelingIntroductionPhilosophy
Pete MalamenThree Phase ReclosersHigh-Side ProtectionSpecific Applications
History –Early 1970’sSmall Substation Transformers <5,000 kVASingle Phase Reclosers – Mostly H typeLimited Three Phase Reclosers – McGraw Type 3
Phase/Ground Trip PlugsNo Sequential CoordinationNo Automation
Current Limit Fuses for UG ProtectionHigh-Side FusesElectromechanical Relays40 Ohm Minimum Fault Resistance
Smaller Reclosers and FusesUse Smallest Recloser which will Carry Load
History - PresentLarger Substation Transformers >5,000 kVASingle Phase Reclosers – 4H & LThree Phase Reclosers w/ Single Phase Trip
Select Settings on PanelSequential Coordination StandardAutomation
Multiple OptionsSwitchgear w/ E fuses for UG ProtectionThree Phase Circuit Switcher/Transducer High-Side ProtectionSolid-State Relays w/ many Options30 Ohm Minimum Fault resistance
Larger Single Phase ReclosersUse Largest Recloser Possible
Sectionalizing Publications
REA/RUS Bulletin 61-2 – Guide for Making Sectionalizing Study on Rural Electric Systems – 1978 (Rescinded)Cooper/McGraw – Distribution System Protection ManualWestinghouse – Applied Protective RelayingCRN Bulletin 96-5 Ground Fault Impedance Values for System ProtectionManufacturer’s Literature
Recloser Interruption & Control
Hydraulic Interruption & ControlLeast Expensive ($1,200-2,300)Maintain @ 5 Year or Less IntervalsSubject to Miscoordination in Winter
Recloser Interruption & Control
Hydraulic Control & Vacuum Interruption
$100 More Expensive per UnitMaintain @ 10+ Year IntervalsSame Miscoordination as AboveHigher Interruption Ratings
Recloser Interruption & Control
Vacuum Interruption & Solid-State Control
Limited MaintenanceMost Expensive (1-ph: $5,700 & 3-ph: $17,000)Coordination Not Affected by TemperatureMost OptionsHigh Interruption RatingsSolid – Type Insulations (e. g. Epoxy)
Recloser Selection
Interrupting RatingLoadMinimum Fault CoordinationSimultaneous Trip
Recloser Ratings
4000----10K4000--------4002004000----84004000--------28014040002500600040002000----20010040002500----40002000----1407030002500----30002000125010050-----2100----210014008757035----1500----150010006255025----900--------60037530154EEWEL4HH
Min.Trip
CoilSize
Recloser TCC
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
70,L(A)
70,L(B)
70,L(C)
70,L(D)
Recloser-Recloser Coordination
C t i A
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
70,L(B)
50,L(B)
70,L(A)
50,L(A)
50,4H(B)
50,H(B)
Simultaneous Trip
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
70,L(B)
50,L(B)
70,L(A)
50,L(A)
600 400
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
70,L(B)
50,L(B)
70,L(A)
50,L(A)
600 400
Simultaneous Trip
i
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
70,L(B)
70,L(A)
35,L(B)
35,L(A)
800
650
Recloser-Recloser Coordination Summary
One Size Smaller Recloser will CoordinateSkipping one Size will Reduce Simultaneous Trip
May Run Out of Sizes
Recloser–Fuse CoordinationType T
Current in Amperes
10 100
1,00
0
10,000
Time In
Sec
onds
.1
1
10
100
1,000
70,L(B)
70,L(A)
25,T(TC)
15,T (MM)
12,T (MM)
Recloser-Fuse CoordinationType 200
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
70,L(B)
70,L(A)
30,N(TC)
15,N (MM)
20,N (MM)
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
70,L(B)
70,L(A)
30,N(TC)
15,N (MM)
20,N (MM)
Recloser-Fuse CoordinationType E
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
70,L(B)
70,L(A)
15<E (MM)
20,E (MM)
30,E(TC) 40,E
(TC)
Recloser-Fuse Summary
Fuse Total Clearing Faster than RecloserDelayFuse Minimum Melt Slower than Recloser FastPick a Standard – Usually Largest Fuse Possible
Fuse-Fuse Coordination
C i A
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
25,T (MM)20,T
(TC)
Fuse-Fuse Coordination (T Type)
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
10,T 15,T 25,T 40,T
Fuse-Fuse Coordination (T Type)
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
30,T20,T12,T8,T
Fuse-Fuse Coordination (T-Bayonet)
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
25,T (MM)
C10 (25A.) Bayonet
Fuse-Fuse Coordination (T-E)
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
10,000
25,T (MM)
25,E MM)(Std & Slow)
C i A
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
25,T (MM)
25,E MM)(Std & Slow)
Fuse-Fuse Coordination (T-K)
i
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
10,000
25,T (MM)
25,K (MM)
Fuse-Fuse Coordination (T-CL)
C i A
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
10,000
25,T (MM)
25, NX C (MM)
25 NXII (MM)
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
25,T (MM)
25, NX C (MM)
25 NXII (MM)
Fuse-Fuse CoordinationSummary
Total Clearing Faster than Minimum MeltStick within a Series or Skip a SizeAvoid Mixing Different Types
Sectionalizing Philosophy
CompromiseCompromiseCompromise
Minimum Fault Resistance
40 OhmOld REA/RUS StandardBased on 1920’s Bell Lab StudiesLargest Single Phase Recloser - 70 Amp Smaller Reclosers and Fuses Overall
Minimum Fault Resistance
30 OhmSupported by CRN 96-5Less ConservativeLargest Single Phase Recloser – 100 AmpLarger Reclosers & FusesFewer Three Phase Reclosers
Minimum Fault Resistance
Values Used by IOU’sNSP/Excel – 20 OhmsMP – 0 Ohms or Twice Load Current
Sectionalizing PhilosophyRecloser Sizing
Smallest vs. Largest vs. HybridSmallest
Smallest Recloser which can carry loadFaster Fault ClearingSmaller Load-Side Fuses
Recloser Sizing
LargestLargest Recloser that CoordinatesLarger Load-Side FusesFewer Changes in Future
HybridSame as Largest, but Size Reclosers to Twice Load LevelLess Simultaneous Tripping
Fast vs. Delay Operations
Substation (1) Fast & (3) Delay
85% Faults TemporaryBetter Coordination with Down-Stream ReclosersFewer Consumers Affected by Interruption
(0) Fast & (3 or 4) DelayPossibly More Outages for Temporary FaultsExcellent Coordination with Down-Stream ReclosersNo Interruption to Affect Electronic or Commercial Loads
Fast vs. Delay Operations
Feeder Reclosers(2) Fast & (2) Delay
Almost UniversalAllows for Temporary Faults to Clear – Fewer OutagesAffects Electronic Equipment – Reset Clocks
Fast vs. Delay OperationsUnderground
(1) DelayNo Temporary Faults on UGShouldn’t Use If Overhead BeyondLeast Amount of Cable Damage
(2) DelayGood Coordination if Fuse Used for Overhead Beyond or Fuses on UGLimited Cable Damage
(2) Fast & (2) DelayNecessary if Overhead Feeder BeyondMost Cable Damage
Recloser Spacing
Mileage Between Reclosers on Three Phase 5 Miles
Sectionalize Circuit MoreShorter OutagesRun Out of Sizes on Long Feeders
10 MilesMore Line to Patrol for Outage – Longer OutagesNot as Likely to Run Out of Sizes Except at 24.9kV
Longer DistanceDifficulty Finding FaultMostly Easily to Backfeed
Tap Protection w/ Recloser vs. Fuse
RecloserSmaller Reclosers or Lightly Loaded ReclosersMore Expensive if have to Purchases ReclosersOne More Operation for Temporary Fault –Fewer OutagesSmaller Fuses on Taps Beyond Recloser
FuseLarger Fuses and on TapReplace Fuse for OutagePossibly More Outages
Feeder Protection
ReclosersSubstationTaps with Load Larger than 20 amps or Longer than 5 MilesEvery 10 Miles Along Three PhaseEvery 10 Miles Along Taps Where Load Larger than 20 AmpsBeyond Special Loads
Feeder Protection
FusesAll Taps or All Taps Longer than Three SpansDivide Taps Longer than 10 Miles
SectionalizersAll Taps that Could be Fuses, But Would Overload Fuse
Minimum Line Recloser & Fuse Size
What Size Transformer Fuse Do You Want to Coordinate?
Minimum Recloser & Fuse Size
What Size Transformer Fuse Do You Want to Coordinate?
25 kVA – 6,T
Minimum Recloser & Fuse Size
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
6,T (TC)
10,T
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
6,T (TC)
10,T
Minimum Recloser & Fuse Size
What Size Transformer Fuse Do You Want to Coordinate?
25 kVA – 6,TLine Fuse – 10,T
Minimum Recloser & Fuse Size
C i A
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
6,T (TC)
10,T
25,4H(B)
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.1
1
10
100
1,000
6,T (TC)
10,T
25,4H(B)
Minimum Recloser & Fuse Size
What Size Transformer Fuse Do You Want to Coordinate?
25 kVA – 6,TLine Fuse – 10,TRecloser – 25 amp
Fuses in Series
ConsiderationsDamage to Upstream FusesMinimum Fuse SizeCoordination LimitationsAvoid as Much as Possible
Sectionalizing
Rick SeelingIntroductionPhilosophy
Pete MalamenThree Phase ReclosersHigh-Side ProtectionSpecific Applications
Three Phase Reclosers
Hydraulic Reclosers
Recloser with CT’s & Solenoids
Electronic Control
Triple-Single Option
1Ø Trip, 1Ø L.O.1Ø Trip, 3Ø L.O.3Ø Trip, 3Ø L.O.
Current in Amperes
100
1,00
0
10,0
00
100,
000
Tim
e In
Sec
onds
.01
.1
1
10
100
1,000
100 A PU, TD=2 U4-US Ext Inv
300 A PU, TD=2 U4-US Ext Inv
200 A PU, TD=2 U4-US Ext Inv
Time Dial Settings
Current in Amperes
100
1,00
0
10,0
00
100,
000
Tim
e In
Sec
onds
.01
.1
1
10
100
1,000
200 A PU, TD=4 U4-US Ext Inv
200 A PU, TD=1 U4-US Ext Inv
200 A PU, TD=2 U4-US Ext Inv
Pickup Settings
Current in Amperes
100
1,00
0
10,0
00
100,
000
Tim
e In
Sec
onds
.01
.1
1
10
100
1,000
100 A PU, TD = 4 U2-US Inverse
300 A PU, TD = 2 U4-US Ext Inv
Phase – Ground Coordination
ANSI Standard Device Designation Numbers
25) Synchronizing or Synchronism-Check Device Is a device that operates when two a-c circuits are within the desired limits of frequency, phase angle, or voltage, to permit or to cause the paralleling of these two circuits.
27) Undervoltage Relay Is a relay that functions on a given value of under-voltage.
32) Directional Power Relay Is a device that functions on a desired value of power flow in a given direction or upon reverse power resulting from arcback in the anode or cathode circuits of a power rectifier.
50) Instantaneous Overcurrent or Rate-of-Rise Relay Is a relay that functions instantaneously on an excessive value of current or on an excessive rate of current rise, thus indicating a fault in the apparatus or circuit being protected.
51) A-C Time Overcurrent Relay Is a relay with either a definite or inverse time characteristic that functions when the current in an a-c circuit exceed a predetermined value.
ANSI Standard Device Designation Numbers
52) A-C Circuit BreakerIs a device that is used to close and interrupt an a-c power circuit under normal conditions or to interrupt this circuit under fault of emergency conditions.
59) Overvoltage Relay Is a relay that functions on a given value of over-voltage.
67) A-C Directional Overcurrent Relay Is a relay that functions on a desired value of a-c overcurrent flowing in a predetermined direction.
79) A-C Reclosing Relay Is a relay that controls the automatic reclosing and locking out of an a-c circuit interrupter.
81) Frequency Relay Is a relay that functions on a predetermined value of frequency (either under or over or on normal system frequency) or rate of change of frequency.
89) Line Switch Is a switch used as a disconnecting, load-interrupter, or isolating switch in an a-c or d-c power circuit, when this device is electrically operated or has electrical accessories, such as an auxiliary switch, magnetic lock, etc.
One-line Diagram
Conductor Arcing through Asphalt
Conductor Breakage / Glassification
Steady State Harmonic Energy
Arcing Fault Harmonic Energy
Substation Protection
Current in Amperes
100
1,00
0
10,0
00
100,
000
Tim
e In
Sec
onds
.01
.1
1
10
100
1,000
10,00065E SMD-Standard -Total Clear A0.87 Low-Side Line to Line Fault
Mechanical Damage
Inrush
Thermal Damage
5,000 kVA, 69-12.47 kV Transformer
65E SMD-Standard -Total Clear A1.73 Low-Side Single Line to Ground Fault
65E SMD-Standard -Total Clear Low-Side Three Phase Fault
Substation Transformer
Current in Amperes
100
1,00
0
10,0
00
100,
000
Tim
e In
Sec
onds
.01
.1
1
10
100
1,000
10,000
Mechanical Damage
Thermal Damage
Inrush
12/16/20 MVA, 69-12.47 kV Transformer
150E SMD-Standard -Total Clear
150E SMD-Standard -Total Clear A1.73 Low-Side Single Line to Ground Fault
Low-Side Three Phase Fault
Large Substation Transformers
Zones of Protection
Differential Relays
C.T. Curves
Transformer Protection
One-line Diagram
Specific Applications
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.001
.01
.1
1
10
100
1,000
GE 10% Probability Case Rupture 100 kVAr Units
15 T -Total Clear
15 T -Minimum Melt
Capacitor Protection
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.001
.01
.1
1
10
100
1,000
GE 10% Probability Case Rupture 100 kVAr Units
15 T -Total Clear
15 T -Minimum Melt
25 T -T otal Clear
25 T -Minimum Melt
Parallel Capacitors
Current in Amperes
10 100
1,00
0
10,0
00
Tim
e In
Sec
onds
.001
.01
.1
1
10
100
1,000
100 kVAr Units
GE 10% Probability Case Rupture
25 T -Total Clear
25 T -Minimum Melt
25K NX Companion Fuses -Minimum Melt
25K NX Companion Fuses -Total Clear
Capacitor with C.L. Fuse
Current Limiting Fuses
Partial range C.L. fusesPad/Pole TransformerOverhead capacitors
Underground applicationsPower qualityHard to coordinate areas
Step Down Transformer Protection
Automatic Loop Restoration - 5 Reclosers
Substation 1 3.3 miles
R
3.3 miles
Substation 2
R
N.O.RecloserR
N.C.Recloser
N.C.Recloser
N.C. - Normally-ClosedN.O. - Normally-Open
R
R
N.C.Recloser
N.C.Recloser
3.3 miles
Loop Coordination
Loss of VBy # of recloses & loss of VNormal O.C. & comm.Current diff & comm.
Control Logic
Questions & comments
