Okay,
Here's the setup:
I have a project I am working on that uses heating coils in a kiln type setup.
The whole thing is 240V 25-30amps
I'm using a PID to control the elements, as I am hoping to hold precise temperatures inside the kiln.
Something about my setup is killing SSR (relays) My relays are rated to 40A, 240V output, and the PID/input site is something like 3-32V.
The switching and everything works fine, kiln heats up for awhile, but then within an hour, the SSR fails and gets stuck open.
Though the SSR does have a heat sink with thermal paste, but heat could potentially be the cause.
However, I feel like the issue is the sudden stopping and starting of such a large load on the SSR, as the PID flicks the SSR on and off several times a minute when it's trying to maintain the correct temperature.
As a novice with electrical projects I want to confirm:
Is the switching of the load a potential issue? --> Using the water analogy, I picture a "water hammer" type event, where the sudden switch off causes a voltage spike, or something similar?
Any tips or solutions? I have gotten this far just reading various web pages, but now that I've killed 3 SSRs, and it's beginning to get expensive, I need help!
Thank you! Seems like a nice forum you have here!
JW
Here's the setup:
I have a project I am working on that uses heating coils in a kiln type setup.
The whole thing is 240V 25-30amps
I'm using a PID to control the elements, as I am hoping to hold precise temperatures inside the kiln.
Something about my setup is killing SSR (relays) My relays are rated to 40A, 240V output, and the PID/input site is something like 3-32V.
The switching and everything works fine, kiln heats up for awhile, but then within an hour, the SSR fails and gets stuck open.
Though the SSR does have a heat sink with thermal paste, but heat could potentially be the cause.
However, I feel like the issue is the sudden stopping and starting of such a large load on the SSR, as the PID flicks the SSR on and off several times a minute when it's trying to maintain the correct temperature.
As a novice with electrical projects I want to confirm:
Is the switching of the load a potential issue? --> Using the water analogy, I picture a "water hammer" type event, where the sudden switch off causes a voltage spike, or something similar?
Any tips or solutions? I have gotten this far just reading various web pages, but now that I've killed 3 SSRs, and it's beginning to get expensive, I need help!
Thank you! Seems like a nice forum you have here!
JW
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