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DuraKool--Mercury contactor failure mode

Rudy

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Today, I believe I had a mercury relay (DuraKool) intermittently fail ON.

Is it possible for a mercury relay to fail ON? I can see how it can fail to close...but stick ON????
 

Randy

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Today, I believe I had a mercury relay (DuraKool) intermittently fail ON.

Is it possible for a mercury relay to fail ON? I can see how it can fail to close...but stick ON????
Yes, I've seen the Durakool relay stick On. I found that the MDI mercury relays are a better relay. I've never had a MDI rely fail yet.
 

OurTown

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Today, I believe I had a mercury relay (DuraKool) intermittently fail ON.

Is it possible for a mercury relay to fail ON? I can see how it can fail to close...but stick ON????
 
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Rudy

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Follow up question....

The mercury contactor in question controls either a 1/2 or 3/4 HP trolley motor in my automatic bay. At 120v...the amp draw is approx 10 or 13 amps depending upon which sized motor I use.

My question...

The mercury contactors are VERY reliable. I see that they are being replaced with SSR Solid State Relays....often called "hockey pucks".

Would a 25amp (or even 40amp) SSR be just as reliable?
 
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