Transcript Advanced Synchro Check Module 3

Module 3 - Synchro Check Relay Testing & Maintenance
Synchro Check Relay Testing
Table of Contents
Introduction
Relay Application
Operation
Relay Inspection And Maintenance
Adjustments
Module Study Questions
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Module 3 - Synchro Check Relay Testing & Maintenance
OBJECTIVES
Upon completion of this module, the participant should be able to:
1.
2.
3.
Describe the common applications for Synchro-Check relays.
Name the NEMA number for Synchro-check relays.
Describe the five different synchro-check options.
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Module 3 - Synchro Check Relay Testing & Maintenance
Relay Application
ANSI Number 25 used for
Check Synchronism between systems
Permissive for energizing dead systems
Prevents circuit breaker closure unless safe condition exist
ANSI Number 25 used to protect
Generators
Circuit breakers between two sources
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Module 3 - Synchro Check Relay Testing & Maintenance
Relay Operation
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





Measure “delta V” between systems
Measure phase angle difference between systems
Check phase rotations between systems
Measure “slip frequency”
Dead line / Dead Bus
Dead Line / Live Bus
Live Line / Dead Bus
1.
Operates on any combination of above conditions depending on
setting and capabilities
Uses two coils which provide reset and operating torque
Not used as an Auto-synchronizer
2.
3.
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Module 3 - Synchro Check Relay Testing & Maintenance
Internal Schematics
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Module 3 - Synchro Check Relay Testing & Maintenance
Internal Schematics
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Module 3 - Synchro Check Relay Testing & Maintenance
Acceptance Testing & Maintenance Testing
1.
Acceptance Testing
•
First Installation
•
Very Thorough
•
Test on all Taps
•
Ensure that it will operate with at every setting
2.
Maintenance Testing
•
Annually or by Predictive Maintenance Program
•
As found before any maintenance performed
•
As left after cleaning and maintenance
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Module 3 - Synchro Check Relay Testing & Maintenance
Relay Inspection and Maintenance
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
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Correct Relay?
Relay operating?
Check Tap and Time Dial
Free disc rotation?
Disc has Vertical Air Gap?
Dirt, Moisture, or Rust?
Contacts Free of Burning or Pitting?
Spring color and condition
Target coil even and operates Freely?
Target coil firm?
Connections Tight?
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests – Test Connections
C B A N
Ext. V.M.
CS-7
RLY.
B
Contacts
C
I
E
1
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Ext. V.M.
SR-76
Unit I
N
+
Unit II
A
6
+
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Aux.
+
8
9 10
+
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests – Test Connections
C B A N
Ext. V.M.
CS-7
RLY.
B
Contacts
C
I
E
5
+
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Ext. V.M.
SR-76
Unit I
N
+
Unit II
A
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+
Aux.
+
8
9
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests
1.
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Minimum Pick-Up
•
Apply rated voltage to one input
•
Increase 2nd input voltage until relay contacts chatter
•
Pick up should match bottom of characteristic circle
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests
2.
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Maximum Pick-Up
•
Continue to increase voltage from minimum pick up
test
•
Stop when relay contacts chatter
•
Pick up should match top of characteristic circle
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests
3.
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Timing Test
•
Apply rated voltage to both inputs in phase
•
Ensure relay operates
•
Connect contact monitoring equipment and remove
one voltage
•
Simultaneously apply rated voltage to input and start
timer
•
Contacts should close as per timing characteristic
curve
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests
3.
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Timing Test
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Module 3 - Synchro Check Relay Testing & Maintenance
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests
4.
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Operating Angles
•
Apply rated voltage to both inputs in phase
•
Decrease phase angle of 1 input until contacts chatter
•
Record results
•
Increase phase angle of same input until contacts
chatter
•
Record Results
•
Results should match characteristic circle
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests
4.
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Operating Angles
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Module 3 - Synchro Check Relay Testing & Maintenance
Protective Relay Tests
6.
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DC Target Test
•
Provides Trip Indication
•
Low impedance shunt for disc contacts and spring
•
Minimum Pick up
 Close disc contacts
 Increase current until seal in operates
 2.0 or 0.2 amps based on tap setting
•
Seal in
 After Pick up, release disc contacts
 Coil should remain energized after disc contacts
open
•
Drop Out
 Decrease current until seal in drops out
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Module 3 - Synchro Check Relay Testing & Maintenance
Module Study Questions
1. Where are synchro-check relays used?
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Module 3 - Synchro Check Relay Testing & Maintenance
Module Study Questions
1. Where are synchro-check relays used?
Any breaker between two sources
2. What is the NEMA Designation for Synchro-check
relays?
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Module 3 - Synchro Check Relay Testing & Maintenance
Module Study Questions
2. What is the NEMA Designation for Synchro-check
relays?
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3. Describe the operation of a Live Line / Dead Bus
function?
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Module 3 - Synchro Check Relay Testing & Maintenance
Module Study Questions
3. Describe the operation of a Live Line / Dead Bus
function?
Contacts close if “Line” voltage exceeds live setpoint
and “Bus” input lower than dead setpoint
4. Why are Live Line / Dead Bus functions used?
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Module 3 - Synchro Check Relay Testing & Maintenance
Module Study Questions
4. Why are Live Line / Dead Bus functions used?
Safely energize a dead system
5. Which contacts in Figure 4 are used in the control
circuit?
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Module 3 - Synchro Check Relay Testing & Maintenance
Module Study Questions
5. Which contacts in Figure 4 are used in the control
circuit?
1-2
6. What are the basic steps required to determine the
Minimum pick up?
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Module 3 - Synchro Check Relay Testing & Maintenance
Module Study Questions
6. What are the basic steps required to determine the
Minimum pick up?
Apply rated voltage on one input
Increase voltage on second input until pick up
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