Download BrochureELECTRICAL PRE & POST COMMISSIONING
ELECTRICAL PRE COMMISSIONING
- All pre commissioning tests are conducted for all equipment’s
- A visual check at CT Circuit, not to kept open
- A visual check at VT circuits all the links to be closed
- VT primary is connected to load line
- Restoration of all isolation links and connections
- Restoration of remote alarm and indication links
- Adaption of relay settings
- Circuit breaker trip test position from protection relay by shoring contacts to ensure protection trip
- Power cable/conductor terminated with proper tightness
- Visual check at power transformer for power cable termination, cable box cover, oil level and cooler fan setting
- Visual check for insulation medium level SF6 if applicable.
- Cancellation of PTW (Permit to work) other authorized documents for relevant system prior to energisation.
- No admission for unauthorized personnel in the concern vicinity
- A study of switching programme or the sequence to be executed
- All the panel covers are closed
- All safety actions taken, like keeping fire extinguishers and first aid items
POST COMMISSIONING:
- No abnormality in the system after energization
- Voltage measurement shall be done for all point and found normal
- Phase sequence check for correct rotation
- Phasing check before paralleling two circuits by either hot sticks or VT secondary side.
- If the circuit is loaded, CT secondary current of all cores and phases shall be measured with angle with respect to any one of the phases voltages
- Directional tests shall be done for directional protection, like directional O/C,E/F and distance protection. This test has been explained later
- Stability test shall be done for differential protection
- If applicable, on load test for automatic voltage controller shall be done for transformer.