Burnt contactors....???

mtfallsmikey

Welcome to the Old-School Club!!..sometimes I wonder how some of the factory-installed wiring, etc gets UL certified..never mentioned this before,thank you so much for what you do for our industry!

Empire_2

What I found.....

Reheat set up using 2 of the 4 5KW elements on a pool unit. Upon coming to the job found 2 of the contactors toasted and nothing out of the ordinary to blame. After replacing the 2 contactors, checked amp draw on the Rated 40 amp contactor and measured 32 amps on the 3 phz, 208vac circuit. Now I scratched my head and started to think what could have caused this to happen. With the usual concern on spike and buck in incoming voltage, there was nothing that hit me off the bat.

When replacing the contactors, I notice that from the factory they actually stripped about 1" of wire and bent it in a "U" shaped configuration to take up more of the Lug on the contactor. As I noticed all of these lugs were loose and we all know what loose connections can cause I wondered, if that is a good Idea to U shape the wire or in my opinion, a bad move since once the wire settles,......it will not fit as one might think it should. Any way,...I cut off factory connection and just stripped 1/2" of 8 ga wire and tightened as usual. No problems since and I guess My gripe is why did they do that? Did they think it would have more conductivity? NOT!!! I have never seen this from any Manufacturer and I don't like it if that's the new Norm...:-)

What do you think Carol? or Anyone........

Mike T.

mtfallsmikey

Wire...

Solid or stranded?...Used to do a wrap like that before the advent of clamp-type washers on contactors, etc.

carol_3

I think the manufacturers are doing more and more things that aren't field-worthy--because some new product manager thinks he has a brand new bright idea. Do I sound like an old timer . . .!

Empire_2

It's Stranded...

I feel that the lugs loosened up after a while and that was the end result. They thought they had them tight, but when the strands settle, You get the loose lug.

Mike T.

mtfallsmikey

Any...

Crimp-on fork/ring terminals on there?..I would install them if not..use Sta-Kon brand, 3M, or other good quality type...see if you can get the high-temp terminals used on commercial kitchen equipment. Another source of grief; stranded/solid wire-nutted connections.

carol_3

And thank you!