Well I finally did it and accidentally dry fired my element. Replaced it with one from Bobby at brewhardware and now my panel makes this humming noise anytime the new element is powered. The higher the power input, the louder it is. If I shut off the element, it stops. See the video. As I recall it tripped both the internal breaker and the GFCI on my spa panel. Any ideas?
Humming noise from control panel after dry fire
- Thread starter jeeppilot
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If you tripped a non-GFCI breaker, that says something shorted, most likely due to insulation breakdown from overheating, and that short allowed excess current to flow, until the breakers tripped. This over-current condition could have damaged components (most likely breakers or contactors) in your panel, and now the damaged component "buzzes." It's less likely that something is just loose, although you could check all screw connections for tightness to see if that helps.
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jeeppilot
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Alright. My head isn’t on completely straight so I can’t think if my contractor is downstream of the breaker or not, but I’ll look at that and replace the breaker and whatever components are downstream of it. Thanks!If you tripped a non-GFCI breaker, that says something shorted, most likely due to insulation breakdown from overheating, and that short allowed excess current to flow, until the breakers tripped. This over-current condition could have damaged components (most likely breakers or contactors) in your panel, and now the damaged component "buzzes." It's less likely that something is just loose, although you could check all screw connections for tightness to see if that helps.
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Downstream or upstream, it doesn't really matter. Current flows in a loop. Any component in the current loop with the element was subject to the over-current, and could have been damaged. Both the high current breakers, and one, or more. contactors are on the element loop. Do you have a design schematic? If so I can point out for you which components saw the over-current.
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jeeppilot
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Yeah I’ll have to dig it out when I have a few minutes. I’ll message you when I find it.Downstream or upstream, it doesn't really matter. Current flows in a loop. Any component in the current loop with the element was subject to the over-current, and could have been damaged. Both the high current breakers, and one, or more. contactors are on the element loop. Do you have a design schematic? If so I can point out for you which components saw the over-current.
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jeeppilot
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@doug293cz sent you the file via message on HBT. Its the Electric Brew Supply BIAB build.
I got the schematics you sent.
Your dry fire and element failure should not have tripped the internal circuit breaker in the panel, as none of the element current flows thru this breaker (it protects the pump and other non-element wiring.)
You have two contactors (main power, and element power enable) that carry all current that flows thru the element, and these are likely candidates for damage from an over current event. However, I see that both of the contactors have contacts rated at 63A, so it seems that they should have been ok with a short over current event. What is the smallest circuit breaker upstream from your control panel (either in your service panel or your spa panel)?
You could try to isolate where the noise is coming from by using a long necked, plastic funnel as stethoscope. Point the small opening at different components, and hold the funnel end to your ear. Wear thick rubber gloves while doing this.
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Your dry fire and element failure should not have tripped the internal circuit breaker in the panel, as none of the element current flows thru this breaker (it protects the pump and other non-element wiring.)
You have two contactors (main power, and element power enable) that carry all current that flows thru the element, and these are likely candidates for damage from an over current event. However, I see that both of the contactors have contacts rated at 63A, so it seems that they should have been ok with a short over current event. What is the smallest circuit breaker upstream from your control panel (either in your service panel or your spa panel)?
You could try to isolate where the noise is coming from by using a long necked, plastic funnel as stethoscope. Point the small opening at different components, and hold the funnel end to your ear. Wear thick rubber gloves while doing this.
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jeeppilot
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Ill give the funnel idea a try to further isolate the noise. My smallest breaker is a 30 amp GFI on the spa panel.I got the schematics you sent.
Your dry fire and element failure should not have tripped the internal circuit breaker in the panel, as none of the element current flows thru this breaker (it protects the pump and other non-element wiring.)
You have two contactors (main power, and element power enable) that carry all current that flows thru the element, and these are likely candidates for damage from an over current event. However, I see that both of the contactors have contacts rated at 63A, so it seems that they should have been ok with a short over current event. What is the smallest circuit breaker upstream from your control panel (either in your service panel or your spa panel)?
You could try to isolate where the noise is coming from by using a long necked, plastic funnel as stethoscope. Point the small opening at different components, and hold the funnel end to your ear. Wear thick rubber gloves while doing this.
View attachment 810027 Amazon
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jeeppilot
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Quick update…it was definitely the main power contactor. Killed power to the whole controller via my GFI breaker, checked for loose connections. None. Reset GFI breaker and now the humming is gone. Something in resetting the GFI breaker fixed the contactor?I got the schematics you sent.
Your dry fire and element failure should not have tripped the internal circuit breaker in the panel, as none of the element current flows thru this breaker (it protects the pump and other non-element wiring.)
You have two contactors (main power, and element power enable) that carry all current that flows thru the element, and these are likely candidates for damage from an over current event. However, I see that both of the contactors have contacts rated at 63A, so it seems that they should have been ok with a short over current event. What is the smallest circuit breaker upstream from your control panel (either in your service panel or your spa panel)?
You could try to isolate where the noise is coming from by using a long necked, plastic funnel as stethoscope. Point the small opening at different components, and hold the funnel end to your ear. Wear thick rubber gloves while doing this.
View attachment 810027 Amazon
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Quick update…it was definitely the main power contactor. Killed power to the whole controller via my GFI breaker, checked for loose connections. None. Reset GFI breaker and now the humming is gone. Something in resetting the GFI breaker fixed the contactor?
Have you considered installing a "Snubber Capacitor Circuit" to your contactor control line. When I first built my panel my contactors would hum/squeal on occasion and after I installed Snubbers on each contactor the noise disappeared. The contact points/pads inside the contactor make noise when not latching completely due to repeated open/close action (arching) thus buildup occurs on these pads. The Snubber will help smooth out the latching current thus less wear and tear on the contactor in the longrun. Keep in mind this won't address your GFI breaker issue.
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