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I am missing something here.
Your first post said L1 to Neutral was 120.
Now across the Control Power Transformer which is what I assume is the low voltage transformer you only have 80 volts.
The wiring diagram shows that this Xfmer is connected to L1 and Neutral so it should have 120 volts also.
Perhaps it has an internal short to ground on the primary.
But that still does not explain the above.
Neutral and Ground should be separate entities. Though I did notice they hooked the thermostat to chassis instead of isolating it and using Neutral.
In my opinion this sort of defeats the purpose of a 4 wire hook up but lets them use the old style of thermostat.
It could be a bad varistor in the electronic filter. I would just remove it from the circuit and see if it corrects the problem. It is just there to ground out high voltage spikes, protecting the electronics. Do not know how to check these without special testing equipment. You have to raise the voltage on them till they hit their break over point. |
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Just checked the bulletin for Whirlpool-Kitchen Aid ovens, and like "Denman" said it is 120vac primary 11.5 secondary and is wired L1-N
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Yes, you are missing something, you did not read all of the post. I said that I had the low voltage to ground on L1 not L2 and the 2ndary winding was open. I do not know what the low voltage is supposed to be, I've been told 12-15v, 20vdc and I have personally measured 25vac on a simular oven. The point is there is 180v on L2 to ground & 70v on L1 to ground. The readings to neurtal are 120 on each leg & 240 between them.
The primary could be shorted to ground.
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Originally Posted by: Earl Dryer  Yes, you are missing something, you did not read all of the post. I said that I had the low voltage to ground on L1 not L2 and the 2ndary winding was open. I do not know what the low voltage is supposed to be, I've been told 12-15v, 20vdc and I have personally measured 25vac on a similar oven. The point is there is 180v on L2 to ground & 70v on L1 to ground. The readings to neutral are 120 on each leg & 240 between them.
The primary could be shorted to ground. You should re-read your post. You clearly state L2-ground 70vac. You have a short to ground period. And Whirlpools technical bulletin states "Primary" 120vac, "Secondary" 11.5 vac.
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My question was regarding this part of your post
"I have an open secondary but I only have 80v to primary so even with a good Xfmr my LV output is going to probably pretty low too."
But the Xfrm is not connected to ground. It is connected to L1 and Neutral so you should see the 120 volts across the primary.
So I am still confused. |
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So,what does that tell you?
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It tells me that when you measure across the transformer primary you are not actually connected to L1 and Neutral but are most likely measuring L1 to chassis.
How this is happening, that is the big question!!!
Unfortunately the tech info does not give an actual electronics schematic.
I would conclude though that there has to be an open in the connection from the primary to either L1 or Neutral otherwise you would see the 120 volts at the primary. |
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Question ? Why not disconnect your transformer primary and wire it with a test cord? This will let you know that the transformer is good and that you have a problem in the wiring.
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Well folks, I don't know how all the attention got to the transformer, I know it is bad. I disconnected it and ohmed it, the secondary is open the primary showed some resistance (don't recall how much).
My original question was why do I have the correct voltages between line & neutral and a large difference between line and chassis ground. Neutral & Ground should be at the same potential.
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I am not focusing on the transformer but on the connection points which just happen to be at the transformer.
Why when connected to L1 and Neutral at the transformer do you see a low voltage when at other places in the unit you see the full 120 (L1 to N)?
Something very weird is happening. Finding out what that is may help troubleshoot.
You may even just be reading stray voltage. Get a 10 to 20 watt, 120 volt bulb, solder a couple wires to it and check from L1 to ground and L2 to ground. If she lights up it is real if not it is probably stray (volts but no real amps).
This is just safer than trying it with the amps setting and blowing a meter. Could also put a resistor in line with one of your meter leads to keep any current below the meter's max.
You said you disconnected the transformer, did you check L1 and L2 to ground with it disconnected re: P24-3 to P24-1?
I would also disconnect most plugs from the board, this should help eliminate any external causes, looks like the only one you need for power is P24 |
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