BULLETIN FROM....

Fall 1999

Preventative Maintenance of
Miscellaneous Electrical Apparatus

An often unnoticed area in schools is the non-rotating electrical apparatus (switchgear and cable connections).

Recently, one of our Boiler & Machinery Consultants walked into an electrical room on a routine inspection and detected an odor suggesting something was overheating. An electrical contractor was called in and it was found that a number of cable connections in the panel were loose. Some cables were too hot to touch! The connections were made tight and there was a happy ending to the story.

Here are a few points to consider regarding the preventative maintenance of miscellaneous electrical apparatus.

1. Aluminum expands and contracts considerably due to changes in temperature and is also quite soft and will corrode (oxidize) under the right conditions. Loose a/o corroded connections can result in overheating and subsequent arcing. All connections should be checked tight and exposed cable should be penetroxed to prevent oxidation.

2. Other cable, including copper, should be checked tight and for discoloration and heating. Repairs should be made where necessary.

3. Infra-red testing on medium to large panel boards has proven to be a good preventative maintenance tool showing hot spots - potential failure situations.

4. Ensure that moisture or water cannot get into any switch boards or other electrical panels - this is a common cause of failures - if at all possible, water tanks and piping should not be located in electrical rooms. Dirt/dust should be blown out annually with dry (moisture-free) low pressure (50 p.s.i. max.) air or vacuumed.

5. All switchgear should be exercised annually. This tests the mechanical integrity of this equipment.

6. Keep electrical rooms clean and dust free as possible - paint floors if pertinent, filter ventilation air, keep doors closed.

7. Keep electrical rooms free of storage clutters to eliminate fire hazard and to give free access to the apparatus.

8. Location of buried cables should be known so that anyone digging will know where they are. Damaging buried cable could cause immediate catastrophic results or, undetected damage to the cable's sheath could manifest itself only much later, both, with possible injury and high resultant costs.

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