Main Objective of Commissioning
The main objective of the test is to check the proper operation function of the circuit breaker; in this test we do the following:
A. Close Operation Test – Local—Remote
This test is conducted by manual, Local and Remote.
For the manual Operation test, we will charge the spring manual and breaker is also closed my manual and opening also done. For the Local operation we give Control supply and A.C supply for spring charge motor.
We close the Circuit Breaker using the TNC (Trip Neutral Control) switch.
If its site is not ready for this, we provide a local signal to the remote terminal and observe the operation of breaker.
B. Trip Operation Test – Local-Remote
This test is conducted by manual, Local and Remote. For the manual Operation test, The manually charged breaker is opened using the Trip switch.. For the Local operation we give Control supply and A.C supply for spring charge motor. We open the Breaker using the TNC switch.
If its site is not ready for this, we provide a local signal to the remote terminal and observe the operation of breaker.
C. Protection Trip
For this test the breaker has in closed position at initially. We provide an auxiliary rated voltage to Master trip relay, and observe the opening of the breaker and the position of the trip coil.
Functional Check
1. Emergency Trip
For this test the breaker has to be in charged or ON position, we operate the emergency push button. We observe the operation of circuit breaker opening.
2. Aux. Switch Operation
When the breaker is in open condition we check the Aux. contact of the breaker using continuity tester, to conform the contact is in NO /NC. Then we close the Circuit Breaker and check the same contact with continuity tester, to conform the contact is in NC /NO.
3. On-Off Indications (Lamp + Flag)
When the breaker is in open condition we check the Lamp + Flag of the relay. Then we close the Circuit Breaker and check the same Lamp operation.
4. Trip / Trip circuit healthy Lamp Indication
The relay is operated and we observer the Trip lamp indication.
5. Limit Switch for spring charge motor
We give an A.C power to motor and observer the operation of motor and charging of spring, on the indication of fully charged spring the motor operation has to get stopped.
6. Test / Service Limit Switch
This test is conducted to check the Test / Service Limit Switch Operation. During rack out the Breaker we obverse the indicator to change to test position and during rack in the breaker we obverse the indicator to change to service.
7. Operation Counter
This test is conducted if operational counter provision is available in breaker. We operated the breaker and look for the change in counter for counting the operation.
8. Heater / Heater Switch / Thermostat
The control A.C supply is given for heater and we look for heater operation.
9. Function of illumination and socket switch
In this test we look for the panel internal illumination and socket switch operation. We operate the limit switch manually and observe the operation of illumination circuit.
Reference: Commissioning of HT electrical system – Sterling & Wilson Ltd.
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Edvard Csanyi
Hi, I'm an electrical engineer, programmer and founder of EEP - Electrical Engineering Portal. I worked twelve years at Schneider Electric in the position of technical support for low- and medium-voltage projects and the design of busbar trunking systems.I'm highly specialized in the design of LV/MV switchgear and low-voltage, high-power busbar trunking (<6300A) in substations, commercial buildings and industry facilities. I'm also a professional in AutoCAD programming.
Profile: Edvard Csanyi
Dear sir
I want to know about pre commissioning of electrical equipment like HT/LT = motor circuit breaker transformer generator panel board
lightning system protective relay switch gear testing of HT/LT cable and 132/33 kv yard
1- Relay installed on 11KV Circuit Breaker is
a) Current operated
b) Voltage operated
current operated
One sf6 breaker gas pressure low and C.B Blocking alarm appeared in annunciator.. in this situation can possible to breaker operation with by pass . is it safety procedure. let give me suggest
Dear sir ,
as we are facing problem of tnc switch that sometime it does not operate whenever auto changeover took place.
Do you have some other tnc switch based on plc logic and how it work on it and what changes have to be made with traditional one.
I may gathered a lot…. Its very usefull for us….
Thanks
when breaker is in operation, we will keep the switch in Close position. Now if any external fault occur whose NC contact is in trip circuit, how breaker will trip as switch is in close position?
please elaborate function of TNC switch along with breaker, it will be great help
Dear Manirul,
Your answer is “ANTIPUMPING RELAY”, it is a specially designed relay for the protection of closing coil to preventing contionous supply to it, as its NO is taken in closing ckt.
so,after once you given a close command through TNC switch,it does’nt matter if you’re holding the switch continously, the bkr will trip if a fault occurs.
Nice informative website….
how to read relay installation pannel.i need ref books,