Sectionalizing
„
Rick Seeling
„
„
„
Introduction
Philosophy
Pete Malamen
„
„
„
Three Phase Reclosers
High-Side Protection
Specific Applications
History –Early 1970’s
„
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Small Substation Transformers <5,000 kVA
Single Phase Reclosers – Mostly H type
Limited Three Phase Reclosers – McGraw Type 3
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Current Limit Fuses for UG Protection
High-Side Fuses
Electromechanical Relays
40 Ohm Minimum Fault Resistance
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Phase/Ground Trip Plugs
No Sequential Coordination
No Automation
Smaller Reclosers and Fuses
Use Smallest Recloser which will Carry Load
History - Present
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Larger Substation Transformers >5,000 kVA
Single Phase Reclosers – 4H & L
Three Phase Reclosers w/ Single Phase Trip
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Switchgear w/ E fuses for UG Protection
Three Phase Circuit Switcher/Transducer High-Side Protection
Solid-State Relays w/ many Options
30 Ohm Minimum Fault resistance
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„
Select Settings on Panel
Sequential Coordination Standard
Automation
Multiple Options
Larger Single Phase Reclosers
Use Largest Recloser Possible
Sectionalizing Publications
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REA/RUS Bulletin 61-2 – Guide for Making
Sectionalizing Study on Rural Electric Systems
– 1978 (Rescinded)
Cooper/McGraw – Distribution System
Protection Manual
Westinghouse – Applied Protective Relaying
CRN Bulletin 96-5 Ground Fault Impedance
Values for System Protection
Manufacturer’s Literature
Recloser Interruption &
Control
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Hydraulic Interruption & Control
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Least Expensive ($1,200-2,300)
Maintain @ 5 Year or Less Intervals
Subject to Miscoordination in Winter
Recloser Interruption &
Control
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Hydraulic Control & Vacuum
Interruption
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$100 More Expensive per Unit
Maintain @ 10+ Year Intervals
Same Miscoordination as Above
Higher Interruption Ratings
Recloser Interruption &
Control
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Vacuum Interruption & Solid-State
Control
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Limited Maintenance
Most Expensive (1-ph: $5,700 &
3-ph: $17,000)
Coordination Not Affected by Temperature
Most Options
High Interruption Ratings
Solid – Type Insulations (e. g. Epoxy)
Recloser Selection
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Interrupting Rating
Load
Minimum Fault
Coordination
Simultaneous Trip
Recloser Ratings
Coil
Size
15
25
35
50
70
100
140
200
Min.
Trip
30
50
70
100
140
200
280
400
H
375
625
875
1250
-------------
4H
600
1000
1400
2000
2000
2000
-------
L
---1500
2100
3000
4000
4000
4000
4000
WE
---------------6000
8400
10K
E
900
1500
2100
2500
2500
2500
-------
4E
----------3000
4000
4000
4000
4000
Recloser TCC
1,000
100
TimeInSeconds
10
70,L
(B)
1
70,L
(A)
70,L
(C)
.1
10,000
1,000
100
10
70,L
(D)
Recloser-Recloser Coordination
10
50,L
(B)
70,L
(B)
Time In Seconds
1
50,H
(B)
50,L
(A)
70,L
(A)
50,4H
(B)
C
ti A
10,000
1,000
100
10
.1
Simultaneous Trip
1,000
1,000
100
100
400
400
600
600
50,L
(B)
50,L
(B)
70,L
(B
)
70,L
(B)
1
1
50,L
50,L
(A)
(A)
70,L
70,L
(A)
(A)
10,000
10,000
1,000
1,000
100
100
10
.1.1
10
Time In Seconds
Time In Seconds
10
10
Simultaneous Trip
100
10
650
800
Time In Seconds
70,L
(B)
35,L
(B)
1
35,L
(A)
70,L
(A)
i
10,000
1,000
100
10
.1
Recloser-Recloser Coordination
Summary
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One Size Smaller Recloser will
Coordinate
Skipping one Size will Reduce
Simultaneous Trip
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May Run Out of Sizes
Recloser–Fuse Coordination
Type T
1,000
100
25,T
(TC)
TimeInSeconds
10
15,T
(MM)
1
12,T
(MM)
70,L
(A)
70,L
(B)
Current in Amperes
10,000
1,000
100
10
.1
Recloser-Fuse Coordination
Type 200
1,000
1,000
20,N
(MM)
20,N
(MM)
15,N
(MM)
15,N
(MM)
30,N
(TC)
100
30,N
(TC)
100
10
Time In Seconds
1
1
70,L
(B)
CurrentCurrent
in Amperes
in Amperes
70,L
(B)
10,000
10,000
70,L
(A)
1,000
100
100
70,L
(A)
1,000
.1
10
.1
10
Time In Seconds
10
Recloser-Fuse Coordination
Type E
1,000
15<E
(MM)
20,E
(MM)
30,E
(TC)
40,E
(TC)
100
Time In Seconds
10
1
70,L
(B)
.1
Current in Amperes
10,000
1,000
100
10
70,L
(A)
Recloser-Fuse Summary
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Fuse Total Clearing Faster than Recloser
Delay
Fuse Minimum Melt Slower than
Recloser Fast
Pick a Standard – Usually Largest Fuse
Possible
Fuse-Fuse Coordination
1,000
100
20,T
(TC)
25,T
(MM)
Time In Seconds
10
1
C
i A
10,000
1,000
100
10
.1
Fuse-Fuse Coordination (T Type)
1,000
10,T
15,T 25,T
40,T
100
Time In Seconds
10
1
Current in Amperes
10,000
1,000
100
10
.1
Fuse-Fuse Coordination (T Type)
1,000
8,T
12,T
20,T
30,T
100
Time In Seconds
10
1
Current in Amperes
10,000
1,000
100
10
.1
Fuse-Fuse Coordination (TBayonet)
1,000
100
25,T
(MM)
Time In Seconds
10
C10
(25A.)
Bayonet
1
Current in Amperes
10,000
1,000
100
10
.1
Fuse-Fuse Coordination (T-E)
10,000
1,000
1,000
100
100
25,T
(MM)
Time In Seconds
Time In Seconds
10
25,E
MM)
(Std
&
Slow)
25,E
MM)
(Std
&
Slow)
10
1
25,T
(MM)
1
10,000
10,000
Current in Amperes
C
i A
1,000
1,000
100
100
.1
10
10
.1
Fuse-Fuse Coordination (T-K)
10,000
1,000
25,T
(MM)
10
25,K
(MM)
1
i
10,000
100
1,000
.1
10
Time In Seconds
100
Fuse-Fuse Coordination (T-CL)
1,000
10,000
25,
NX C
(MM)
1,000
100
25,
NX C
(MM)
100
Time In Seconds
Time In Seconds
10
25
NXII
(MM)
10
25
NXII
(MM)
1
1
25,T
(MM)
25,T
(MM)
.1
10,000
10,000
Current in Amperes
C
i A
1,000
1,000
100
100
10
10
.1
Fuse-Fuse Coordination
Summary
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Total Clearing Faster than Minimum
Melt
Stick within a Series or Skip a Size
Avoid Mixing Different Types
Sectionalizing Philosophy
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Compromise
Compromise
Compromise
Minimum Fault Resistance
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40 Ohm
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Old REA/RUS Standard
Based on 1920’s Bell Lab Studies
Largest Single Phase Recloser - 70 Amp
Smaller Reclosers and Fuses Overall
Minimum Fault Resistance
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30 Ohm
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Supported by CRN 96-5
Less Conservative
Largest Single Phase Recloser – 100 Amp
Larger Reclosers & Fuses
Fewer Three Phase Reclosers
Minimum Fault Resistance
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Values Used by IOU’s
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NSP/Excel – 20 Ohms
MP – 0 Ohms or Twice Load Current
Sectionalizing Philosophy
Recloser Sizing
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Smallest vs. Largest vs. Hybrid
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Smallest
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Smallest Recloser which can carry load
Faster Fault Clearing
Smaller Load-Side Fuses
Recloser Sizing
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Largest
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Largest Recloser that Coordinates
Larger Load-Side Fuses
Fewer Changes in Future
Hybrid
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Same as Largest, but Size Reclosers to
Twice Load Level
Less Simultaneous Tripping
Fast vs. Delay Operations
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Substation
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(1) Fast & (3) Delay
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85% Faults Temporary
Better Coordination with Down-Stream Reclosers
Fewer Consumers Affected by Interruption
(0) Fast & (3 or 4) Delay
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Possibly More Outages for Temporary Faults
Excellent Coordination with Down-Stream Reclosers
No Interruption to Affect Electronic or Commercial Loads
Fast vs. Delay Operations
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Feeder Reclosers
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(2) Fast & (2) Delay
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Almost Universal
Allows for Temporary Faults to Clear – Fewer
Outages
Affects Electronic Equipment – Reset Clocks
Fast vs. Delay Operations
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Underground
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(1) Delay
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(2) Delay
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No Temporary Faults on UG
Shouldn’t Use If Overhead Beyond
Least Amount of Cable Damage
Good Coordination if Fuse Used for Overhead Beyond or
Fuses on UG
Limited Cable Damage
(2) Fast & (2) Delay
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Necessary if Overhead Feeder Beyond
Most Cable Damage
Recloser Spacing
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Mileage Between Reclosers on Three Phase
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5 Miles
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10 Miles
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Sectionalize Circuit More
Shorter Outages
Run Out of Sizes on Long Feeders
More Line to Patrol for Outage – Longer Outages
Not as Likely to Run Out of Sizes Except at 24.9kV
Longer Distance
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Difficulty Finding Fault
Mostly Easily to Backfeed
Tap Protection w/ Recloser vs.
Fuse
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Recloser
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Smaller Reclosers or Lightly Loaded Reclosers
More Expensive if have to Purchases Reclosers
One More Operation for Temporary Fault –Fewer Outages
Smaller Fuses on Taps Beyond Recloser
Fuse
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Larger Fuses and on Tap
Replace Fuse for Outage
Possibly More Outages
Feeder Protection
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Reclosers
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Substation
Taps with Load Larger than 20 amps or
Longer than 5 Miles
Every 10 Miles Along Three Phase
Every 10 Miles Along Taps Where Load
Larger than 20 Amps
Beyond Special Loads
Feeder Protection
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Fuses
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All Taps or All Taps Longer than Three
Spans
Divide Taps Longer than 10 Miles
Sectionalizers
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All Taps that Could be Fuses, But Would
Overload Fuse
Minimum Line Recloser & Fuse
Size
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What Size Transformer Fuse Do You
Want to Coordinate?
Minimum Recloser & Fuse Size
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What Size Transformer Fuse Do You
Want to Coordinate?
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25 kVA – 6,T
Minimum Recloser & Fuse Size
1,000
1,000
10,T
10,T
6,T6,T
(TC
) )
(TC
100
100
Time In Seconds
Time In Seconds
1010
1 1
Current
Current
in Amperes
in Amperes
10,000
10,000
1,000
1,000
100
100
10
10
.1 .1
Minimum Recloser & Fuse Size
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What Size Transformer Fuse Do You
Want to Coordinate?
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25 kVA – 6,T
Line Fuse – 10,T
Minimum Recloser & Fuse Size
1,000
1,000
6,T
6,T )
(TC
(TC)
10,T
10,T
10
10
1
1
25,4H
25,4H
(B
)
(B)
10,000
10,000
Current in Amperes
C
i A
1,000
1,000
100
100
.1
.1
1010
Time
Time
In Seconds
In Seconds
100
100
Minimum Recloser & Fuse Size
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What Size Transformer Fuse Do You
Want to Coordinate?
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25 kVA – 6,T
Line Fuse – 10,T
Recloser – 25 amp
Fuses in Series
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Considerations
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Damage to Upstream Fuses
Minimum Fuse Size
Coordination Limitations
Avoid as Much as Possible
Sectionalizing
„
Rick Seeling
„
„
„
Introduction
Philosophy
Pete Malamen
„
„
„
Three Phase Reclosers
High-Side Protection
Specific 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.
Time Dial Settings
1,000
100 A PU, T D=2
U4-US Ext Inv
100
200 A PU, T D=2
U4-US Ext Inv
10
Time In Seconds
300 A PU, T D=2
U4-US Ext Inv
1
Current in Amperes
100,000
10,000
1,000
.01
100
.1
Pickup Settings
1,000
100
200 A PU, T D=1
U4-US Ext Inv
200 A PU, T D=2
U4-US Ext Inv
10
Time In Seconds
200 A PU, T D=4
U4-US Ext Inv
1
Current in Amperes
100,000
10,000
1,000
.01
100
.1
Phase – Ground Coordination
1,000
100 A PU, T D = 4
U2-US Inverse
100
300 A PU, T D = 2
U4-US Ext Inv
Time In Seconds
10
1
Current in Amperes
100,000
10,000
1,000
.01
100
.1
ANSI Standard
Device Designation Numbers
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25) Synchronizing or Synchronism-Check Device
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27) Undervoltage Relay
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„
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
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Is a relay that functions on a given value of under-voltage.
32) Directional Power Relay
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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.
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
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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 Breaker
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59) Overvoltage Relay
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Is a relay that controls the automatic reclosing and locking out of an a-c circuit
interrupter.
81) Frequency Relay
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Is a relay that functions on a desired value of a-c overcurrent flowing in a
predetermined direction.
79) A-C Reclosing Relay
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Is a relay that functions on a given value of over-voltage.
67) A-C Directional Overcurrent Relay
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„
Is 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.
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
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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
Substation Transformer
10,000
65E SMD-Standard -T otal Clear A0.87 Low-Side Line to Line Fault
65E SMD-Standard -T otal Clear Low-Side Three Phase Fault
1,000
65E SMD-Standard -T otal Clear A1.73 Low-Side Single Line to Ground Fault
5,000 kVA, 69-12.47 kV
Transformer
Mechanical Damage
10
T hermal Damage
1
.1
Current in Amperes
100,000
10,000
.01
1,000
Inrush
100
Time In Seconds
100
Large Substation Transformers
10,000
150E SMD-Standard -T otal Clear Low-Side Three Phase Fault
150E SMD-Standard -T otal Clear A1.73
1,000
Low-Side Single Line to Ground Fault
12/16/20 MVA, 69-12.47 kV
Transformer
Mechanical Damage
10
T hermal Damage
1
.1
Current in Amperes
100,000
10,000
.01
1,000
Inrush
100
Time In Seconds
100
Zones of Protection
Differential Relays
C.T. Curves
Transformer Protection
One-line Diagram
Specific Applications
Capacitor Protection
1,000
GE 10% Probability
Case Rupture
100 kVAr Units
100
10
1
15 T -Minimum Melt
.1
Current in Amperes
10,000
1,000
.001
100
.01
10
Time In Seconds
15 T -T otal Clear
Parallel Capacitors
1,000
GE 10% Probability
Case Rupture
100 kVAr Units
100
10
25 T -T otal Clear
1
15 T -Minimum Melt
.1
25 T -Minimum Melt
Current in Amperes
10,000
1,000
.001
100
.01
10
Time In Seconds
15 T -T otal Clear
Capacitor with C.L. Fuse
1,000
100
GE 10% Probability
Case Rupture
100 kVAr Units
10
25 T -Minimum Melt
1
25K NX Companion Fuses -T otal Clear
.1
25K NX Companion Fuses -Minimum Melt
Current in Amperes
10,000
100
.001
1,000
.01
10
Time In Seconds
25 T -T otal Clear
Current Limiting Fuses
„
Partial range C.L. fuses
„
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„
Pad/Pole Transformer
Overhead capacitors
Underground applications
Power quality
Hard to coordinate areas
Step Down Transformer Protection
Automatic Loop Restoration - 5 Reclosers
Substation 1
3.3 miles
3.3 miles
3.3 miles
R
R
N.C.
Recloser
N.C.
Recloser
R
R
N.C.
Recloser
N.C.
Recloser
Substation 2
N.C. - Normally-Closed
N.O. - Normally-Open
R
N.O.
Recloser
Loop Coordination
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„
„
„
Loss of V
By # of recloses & loss of V
Normal O.C. & comm.
Current diff & comm.
Control Logic
Questions & comments