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It all depends on the make of the HT breaker and what the application is. It could be a interlocking field device not in the true state, or safety devices inhibiting the closing of the breaker. If it is a vacuum breaker loss of vacuum pressure could inhibit it also. If it is old type SF6 breakers, low gas pressure could inhibit closing of the breaker. Check for fault messages on the Human Interface Module on the breaker of trip flags if it the older type.
1.Failure of digital Out put Fuse. 2. Control Supply broken.3.Failure of closing coil.4. Interlocking.5. Trip ckt is not healthy.6. Anti Pumping relay is malfunctioning
Failure of control supply.
Intertrip relay from upstream operated.
interface relay is not functioning.
closing coil of the relay failed.
Protection system enabled.
Once 33 KV HT Breaker not clossing from the contrl room, Go to the Breakers room and check Wher there the breaker is pulled out for Maintence if OK, Switch in Remot Mode, then check for any alarm on the control paleals, reset if so, check for Under voltage and clossing Coil/ relonditions.
1. Check for the fault indication and ensure that whether the lockout relays is reset.
2. Check for the interlocking for closing command.
3. Check the incoming supply is there not, because UVT will prevent the breaker closing.
4. Check Breaker Charging mechanism is working or not.
5. Check control fuse.
6. Check closing pushbutton is healthy or not by continuity.
Following things needed to be checked:
1. Breaker operation mode local or remote?
2. Is interposing relay functioning normal?
3. DC closing coil's resistance okay?
4. Is there any interlock operated ?
Actually, this issue can be easily analyzed looking to the SCADA outputs and indications. SCADA system gives a topological monitoring capability to squeeze the problem. The control and monitoring systems has also historical analysis capability which helps to focus in to the right point. The simplest reasons of the unperformed action are the communication problems which can be checked with test commands. The second issue can be physical malfunctioning of the breaker itself or relevant control interface.
Must be checking the main beark.and load all types of electrical
check main switch and switch it off
May be on mannual possition
Interlocking must be checked
closing coil must be checked
Protection relay must be checked
Checking with the current electrician source will be important due to high risk of abroaching to those devices. for example electrician ministry.
