MIDWEST buys surplus, old, used, obsolete, and even ugly circuit breakers. We are paranoid about the history and condition of these previously owned circuit breakers. We are particularly concerned someone will try to sell us breakers that look good, but have been damaged by water. We are especially cautious because of dramatic flooding in recent years. This week we got a call asking us if we wanted to buy like new circuit breakers that were flooded with water. Our polite answer was a screaming “No!” They were honest and told us the breakers had been flooded. We will not even consider buying moisture damaged circuit breakers. They could even be brand new circuit breakers and still, no.
These breakers could be cleaned up cosmetically so they look new and they might even pass the basic electrical tests, but we know they are still junk. If you tore a water damaged breaker completely apart, including the trip device and the operating mechanism, you would find rust and caked on dirt, even mud. Under the stationary contacts, on the trip device hold down bolts, under the trip element, inside the trip element, everywhere in and under the operating mechanism.
The breaker may pass the insulation resistance tests, the contact resistance tests, and maybe even the over current tests. And, if you don’t bother to take the cover off, you might never know that the breaker was damaged by water or extreme humidity. We know that plants that have been flooded will go through a thorough switchgear on site reconditioning process. Switchgear, including circuit breakers, will be restored to operating condition in an effort to get the power back on as quickly as possible. But these are emergency situations and getting replacement equipment quickly may not be possible. So one should not compare such an extreme circumstance with the normal world of a Switchgear Service Shop.
We want to know the history of equipment we purchase and we can not rely on that information being always accurate. Everything must be completely checked out, reconditioned. And because equipment passes standardized tests, does not mean it is reliable for reuse. Reconditioning will determine if it will be reliable after passing the standardize tests and MIDWEST’s other reliability centered tests. But testing alone does not determine reliability.