Preventative Maintenance for Switchgear and Electrical Distribution Systems
It’s easy to get overwhelmed researching what your preventative maintenance for electrical distribution and switchgear
There is more information out there than ever. Some have several hundred pages with only a few pages of relevant items that are actionable. You can spend hours reading and skimming through these documents only to be frustrated. To give you a head start, and a better understanding of your equipment’s condition, we have done that research for you.
The best place to start is looking for any evidence of moisture around the equipment itself. Last time we did a YouTube search, water and electricity does not mix well. Next, visually inspect all doors, panels and sections for paint, dents, scratches and fit. If the switchgear or electrical distribution assets been damaged or seems off, there’s probably a reason why. Ask questions so that you never put yourself in an uncomfortable situation.
Below is a list of items to work on a general preventative maintenance to get the ball rolling:
- Compare equipment nameplate information, including CT and PT ratio, fuse sizes and communication links with the latest one-line diagram and report discrepancies. If the nameplate is damaged/missing, install the properly labeled engraved plastic nameplate, using rivets or screws.
- Inspect for proper alignment, anchorage, grounding and required area clearance.
- Key interlock systems must be physically tested to ensure proper function. Closure attempt must be made on locked open devices. Opening attempt must be made on locked closed devices.
- NOTE - When working on key interlock systems, the key exchange procedures must be observed at both the beginning and end of the job, to ensure that the system cannot be energized without the knowledge of all individuals involved.
- Attempt closure on locked-open devices. Attempt to open locked-closed devices.
- Make key exchange with devices operated in off-normal positions.
- NOTE - When working on key interlock systems, the key exchange procedures must be observed at both the beginning and end of the job, to ensure that the system cannot be energized without the knowledge of all individuals involved.
- Inspect for cleanliness and need of lubrication particularly on current-carrying parts and sliding surfaces that physically move.
- Exercise all active components (providing plant operation is not jeopardized).
- Inspect all indicating devices for proper operation.
- Enter switchboard and perform complete inspection looking for:
- Proper anchoring
- Grounds or shorts
- Evidence of overheating or arcing
- Cable arrangements and supports, cracked or damaged insulator
- Inspect fuse clips for tightness and alignment.
- Inspect operation of shutters & barriers to ensure proper operation.
- Inspect all internal heaters.
- Inspect and align all disconnects.
- Thoroughly vacuum and clean interior (especially the insulating supports for the bus).
- Examine assembly for evidence of leakage from an outside source, such as roof or wall seams, and report any deficiencies found.
- Examine vents and verify filters are clean (i.e., equipped with filters).
- Inspect bolted electrical connections for high resistance using one or more of the following methods:
- Use a low-resistance ohmmeter
- Verify tightness of accessible bolted electrical connections by calibrate torque-wrench method to the manufacturer published data
- Perform thermographic survey to help identify any potential areas of weakness
- Inspect control power transformers using the following methods:
- Inspect for physical damage, cracked insulation, broken leads, tightness of connections, defective wiring, and overall general condition.
- Verify that primary and secondary fuse or circuit breaker ratings match drawings.
- Verify correct functioning of drawout disconnecting and grounding contacts and interlocks.
Everyone with switchgear and electrical distribution equipment all want safe, reliable power and extension of life of. Don’t be that electrical systems owner that neglects their equipment because there hasn’t been a problem. Staying on the front end of any potential issues and the journey to modernization becomes easier to navigate and allows for a methodical road map to be constructed in the future.
Need Help?
If at any point you need assistance, we are here to help. Feel free to reach out to us at any time and member of the power team will review your current PM structure and provide additional insight on potential areas to act in the future.
