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Thermador Oven Relay Board - Need help finding a replacement relay

slimcharger

Feb 6, 2021
4
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Feb 6, 2021
Messages
4
Hi guys,

My older model (SCD302T) Thermador oven has gone kaput and the relays are the fault. I've been trying to find replacement relays, but they have been discontinued long ago.

The relays on the board are:
1) Omron G8P-UA-006055 (047-00067-00), NO15a, NC 10a, 125VAC
2) Omron G8P-UA-006103 (047-00088-00), 30A 250VAC, 15a 125VAC

Can anyone help me find or know of or how to find a new part number for these specific relays?

One thing to note, It seems as though there was a revision to the Thermador boards; I purchased the new model (new part number) relays for the revised Thermador board, but the specs appear to be different from the relays I mentioned above.

1) Omron G8P-1C4P 12VDC, NO 20a, NC, 10A, 250VAC
2) Omron G8P-1A4P 12VDC, 30A 250VAC

Would those relays work in place of the ones on my board?

Here's a picture:

https://drive.google.com/file/d/1G7BzX5BtbY0Rah33dDLt0tEK4CVtXsum/view?usp=sharing
https://drive.google.com/file/d/1rxPC37x8gItsA1gBNvqjGXP1HyCK09th/view?usp=sharing
 

kenny256

Jan 4, 2020
54
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Jan 4, 2020
Messages
54
Assuming the pin spacing and contact and coil location is the same so they can be soldered in, the new ones are just rated higher for higher voltage on the normally open contacts, so they would work.
 

slimcharger

Feb 6, 2021
4
Joined
Feb 6, 2021
Messages
4
The pins and pin spacing are the same - how can I check for contact location?
 

kenny256

Jan 4, 2020
54
Joined
Jan 4, 2020
Messages
54
Remove old relay and measure for continuity across pair of pins to find the NO and NC contacts, measure resistance across the pins for the coil. Then do the same for the replacement relay and compare results to verify they are the same.

For extra credit you could apply 9 to 12V across the coil pins to cause the relay to activate and then measure the continuity of the pins again to show the switching action of NO and NC, etc.

Of course if the relay contacts are frosted over or damaged, then the readings may be affected, which is the reason for replacement. Unless the coils have burned out.

Were both relays "bad"? That seems an unlikely coincidence--more likely the 12V supply for both relays is not working...possibly?
 

slimcharger

Feb 6, 2021
4
Joined
Feb 6, 2021
Messages
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I tested for continuity with my multi meter on both relays. I got a beep of continuity for one of the relays and it's accompanying replacement (8P-UA-006055 and G8P-1C4P) on the same pins, however no continuity beeps at all for the other relay & it's replacement. I take this as a good sign, but I am not sure.

I'll grab a 9V battery at Home Depot while I'm out and test the coil pins.

Upon closer inspection after removing the relay from the board and pulling off the plastic shell top, it looks as though one of the relays contacts is "burnt", while the other relay seems seems to look OK.

Upon even CLOSER inspection, I determined that both of the Old Relays have an additional pin, which I am assuming is for stability on the circuit board as the pin doesn't go anywhere (it's totally isolated). Perhaps it is for ground? The additional pin is coming from the bottom end of the coil, as seen in the picture:

https://imgur.com/4Y89GRN
 

kenny256

Jan 4, 2020
54
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Jan 4, 2020
Messages
54
The one on the top right is definitely suspect with all the soot from arcing, the one on the left might be okay.

The extra pin will have voltage on it as the frame is part of the Common contact. If there are no traces on either side of the board associated with that extra pin then you are good. Functionally it would help with holding the relay in place, and also provide a link to the Common if that were needed somewhere else on the board.
 

slimcharger

Feb 6, 2021
4
Joined
Feb 6, 2021
Messages
4
Gotcha - I installed all the relays and badabing, the relay board is back in action. Thanks for talking me through it. I'll bake a cake in your honor.

Best,

Tyler
 

gotguts

Oct 30, 2022
1
Joined
Oct 30, 2022
Messages
1
Hi Slimcharger - I have the same problem with my Thermador, same relays. What relay did you find to replace yours with? Looks like Digikey et al don't stock the exact G8P-UA-006103 anymore. Did you end up using the G8P-1A4P?
 

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