Water Damaged Electrical Panels

[BobLfoot 302]

We have had some flooding and significant rains here at my plant. The other day we lost a 480 V 20A breaker that would not reset. Investegation revealed that the entire panel had filled with water froma nearby roof leak. We have stopped the roof leak and the panel is drying out. THis breaker still will not reset and we are ordering another to repalce it. It is obvious that several other breakers were waterlogged. SHould these be repalced or are they still functional and "safe" once they dry out. What have others done? Does anyone know of an applicable law or policy? When this happened at my house the insurance company paid for an entire new box. But they are trying to mitigate risk.

[Mike Dyble 0]

First question is was water clean, i.e. if you dry things out will debries/salts etc be left, if water was not clean then recovery is difficult, and probably not worth it If water was clean then providing that you can ensure that all traces of water are removed before you apply power then there is no problem (but if it was wet with power applied the damage may already be done). Really this is down to design and also replacement cost. One technique is to place the affected equipment in a sealed container with a dessicant, for example Calcuim Chloride, which draws the water out, making sure that the dessicant dosnt contact the equipment to be dried. Its worth noting that when I was an apprentice we used to regularly wash the old valve based Tektronix oscilloscopes, and then thoughorly dry them in a large oven as a routine operation. So its the old cost/time and effort balance.

[BudMan 1]

Mike, I also have watched the Tektronix service department do the same (wash with water) when repairing/calibrating the old scopes. Man, do I fell old. Bud

[JeffKiper 9]

Bob First thought was if they are only standard breakers (no electronics) than why not? They only have eutetic alloy (spelling?) and springs in them to allow the snap action to work. Second thought is what will be the end result if these breakers do trip premature or not at all? Where will the loss in product and/or time become a break even point for the cost justification to replace them?

[paulengr 44]

NFPA 70E has something to say about waterlogged equipment. I don't have it in front of me right now but it essentially says that the only way to deal with it safely is to have the manufacturer involved in telling you what is and isn't recoverable (ie, it's a liability thing). Since no manufacturer is willing to take the risk that I know of, this leaves you with no liability choice but to replace them all. Your other choice will be to hire a circuit breaker testing outfit. There are lots of them. It's something of a specialized local business, kind of like local motor shops except more specialized. Whoever you send your gloves/hotsticks to for testing or whoever you have doing IR scans and/or transformer oil testing should be able to give you a name. Heck, I've even compared names/notes with one of our insurance carriers (FM Global). They should be able to help you inspect them all. It's usually more expensive than outright replacement but they should also be able to give you prices on testing all your breakers. They have specialized equipment (not worth your money to buy it) that puts a low voltage, high current test signal across the circuit breaker and times how long it takes for the breaker to open. I've asked several times and every time the local CB shops told me that it is cost prohibitive to test molded case circuit breakers. They always recommend tossing them instead.