Switchgear is an electrical system that performs different electrical functions and helps in supplying power to the entire plant or building. Performing functions like voltage transformation, circuit switching, system protection, and power factor correction metering are all duties of the switchgear.
Switchgears comprise different components like Electrical power apparatus, circuit breakers, capacitors, such as transformers, regulators, air switches, and lightning arresters. Together they form the entire switchgear and make the entire process possible.
So many complex components require proper maintenance to ensure the switchgear’s proper functionality. Also, switchgear not properly maintained could become hazardous and may run into the risk of catching fire due to short-circuiting or too much heating up. Hence switchgear inspection and maintenance become crucial to ensure proper functionality and neutralize the risk of fire and other disasters.
Hence let’s discuss how you can perform a general visual and mechanical inspection of switchgear:
General Visual and Mechanical Inspection of Switchgear
To get started, first of all, start checking the electrical, mechanical, and physical condition of the switchgear, which includes alignment, grounding, anchorage, and required clearances. Then, while performing the acceptance testing, verify that the data on the equipment nameplate matches the project specification and drawings. This step is crucial as the switchgear is designed specifically for an application and should not be used unless the manufacturer explicitly approves it.
The switchgear unit should be clean, and all the loose parts, documentation, etc., should be removed from the cubicles if left inside by mistake. However, documentation should be thrown away as it is necessary. Keep the documentation shipped along the switchgear in a safe and secure place. Meanwhile, the loose parts should also be stored outside the switchgear unit in a safe place for future use. While performing the Switchgear Inspection, ensure to properly clean the switchgear but only buy the cleaning methods accepted by the electrical industry.
For immediate acceptance, the switchboard inspector must verify that the fuse and the circuit breaker type, sizes, and protective device setting are to the point and are the same as the coordination studies and project drawings. Circuit breakers equipped with microprocessor-communication packages must be programmed with correct digital addresses. All the voltage ratios and instrument transformer current should also be the same as the project drawings.
Other Switchgear Inspections
Once you are done with the general inspection, if you find any problem, you must contact professional electrical personnel to conduct further inspections, which will include:
- High voltage test
- Electric test on secondary wiring
- Insulation resistance test
- Operation of circuit breakers and check if they require any change
- Checking all the bush bars
- Checking voltage transformer and current transformer for the records of Vendor’s individual tests.
- Checking all instruments, switches, fuses, contractors, protective relays etc.
- Checking all the wires for the grade and size of wires, their tightness, proper connection, earthing arrangement, and any damage to the wire.
- Checking outgoing and incoming cable glands and boxes.
- Checking all interlock operations and shutters.
- Checking complete board for correct door fitting, finish, setting and ranges of relay meters, etc.
All these tests must be performed on the switchgear every two to three years. But these inspections should only be performed by a professional, and no other person should try to perform these tasks as they could be very risky for a person who does not have the proper electrical knowledge.
Switchgear inspection, testing, and maintenance regularly are very crucial safety measures. The companies claim that some parts do not require any additional care, but even these parts should be inspected properly and thoroughly to ensure proper functionality.
This not only ensures the proper functionality of the switchgear but also helps you financially by warning you which parts require maintenance before the situation comes where you have to replace them.