Crest CKS400 Amp - Buzzing Relay

[Baldrick]

Hi all. I've got a Crest CKS400 amp that's got a buzzing power relay.

Originally, the relay would buzz until the unit was turned off. Now, it buzzes for a second and stops. The relay also shows a blue spark when first powered.

My question is, is it likely this is just a bad relay (Potter & Brumfield K10P-11A15-120) or do you thing it's something else making the relay lose it's mind?

Thanks!

[R_J]

Re: Crest CKS400 Amp - Buzzing Relay

I assume you are talking about the ac input relav. The relay is driven from the ac line so It should not be coil voltage problem, so it is likey a bad relay

[Baldrick]

Re: Crest CKS400 Amp - Buzzing Relay

Thanks for taking the time!

I've got a new relay ordered and I'll post the results.

[budm]

Re: Crest CKS400 Amp - Buzzing Relay

Is that relay coil driven by the OPTO MOC3041? May be the OPTO is getting weak,

[R_J]

Re: Crest CKS400 Amp - Buzzing Relay

I believe the opto is for remote turn on/off (STO)
I like the names on the connections on the power switch: YES, NO, MAYBE? I believe it is Remote

[budm]

Re: Crest CKS400 Amp - Buzzing Relay

Some EE guy with humor.

[clearchris]

Re: Crest CKS400 Amp - Buzzing Relay

Relays have a limited lifespan, it's a wear part, and if it's buzzing and arcing, the contacts are already hosed. Can't go wrong replacing it. It's true as budm said, to directly answer your question, it could be something else. But it's not likely.

When fixing things, I play the odds first, then if that doesn't work, time to dig deeper. I wouldn't sweat it. But then again, I'm just an electronics hack.