About my wall oven.........

[customline]

Just put two Robertshaw thermostats into my "57 Customline. Wiring, to the best of my knowledge is correct (directions say wiring to the thermo is identical to original wiring) and unit is not working. Clock is not running and I got two dim indicator lights which are suppose to be off when unit is turned off. Just about everything is haywire. Anybody experience this with after market thermostats?

 

[mattl]

Are you working without a circuit diagram?  Sounds like a few wires got crossed.  Been a while since I did a replacement, but often they are not pin for pin the same.  they may be functionally the same, but a few contacts may be moved around.

 

[customline]

Yes......

I have a wiring diagram. It's as if the new thermostats or the oven switches need to be wired differently. Top oven light won't come on when light switch is pressed or when door opens but will come on dimly when timed bake is selected and thermostat is on.

 

[circlew]

Are you sure you have the correct wiring coming into this oven from the electric panel? This requires a grounded 3-wire 120/240 volt circuit. The cable coming in should have black, red, white, and bare or green grounding conductors. And is the wiring connected to the terminal block correctly? The oven light and clock not working properly make me question this. While the wires going to the light may tie in to other wires at the control or thermostat, the current going to it should not pass through it. I would keep the circuit breaker shut off until I got this figured out.

Does the lower oven light work?

 

[customline]

The house wiring......

is correct. 10 gauge 3 wire with ground. When I first ran the oven with the original thermostats it worked fine. The only reason I wanted to replace the original thermostats is because they were not keeping constant temperature. Something tells me these new thermostats work differently although they are suppose to wire up like the original (that's what the directions say anyway).

 

[mattl]

From looking at the schematic it would appear that the red lines are on a normally closed set of contacts in the thermostat, and the black lines are on a normally open set.  Did you check with a VOM to see if that is the case?

 

did you replace both or just one?

 

[arbilab]

Thermo alone should not be able to affect clock. Meter if clock is powered. Clock motor is almost always the first thing to fail and completely independent of thermo.

Miswiring thermo might somehow result in neon lamps being in series with oven elements.

The complex switch is bake/broil/time. Current ones put 120V on the broil element in bake. I don't know if that was true in 1957. You didn't replace that. But you also didn't specify that the set was working properly before the thermo replacement.

I can't see any way replacing the thermos could cause the clock to stop. Can you?

 

[customline]

You're absolutely right.......

I can't see why the clock would stop because of a thermo replacement. Clock was rebuilt and was working before both thermostats were replaced. I have both thermo indicator lamps wired into the first terminal and grounded into neutral on the first switch as on the schematic. I tested the bottom thermo at bake and on 350 degrees. Indicator light starts at dim and when bake is on it brightens.The thermo works correctly but the indicator light should be off when bake switch is off. Maybe I should move the indicator light hot wire?

 

[toggleswitch]

Have to read this better, but I am guessing there is a problem with the neutral.

WHY or how I don't know.

May be related to BROIL element on 120v during bake operation.

Of course biggest concern is to ensure 240v doesn't get to 120v components......

 

[cuffs054]

I got to go with neutral as well. The new thermos may need to go to "ground" as opposed to "neutral" and/or in addition to. I'm not seeing where you indicate that these are exact replacements.

 

[customline]

The replacements........

according to the Robertshaw literature are suppose to be exact. Directions say wire the thermos up just like the original thermos. Maybe I should go with GE replacements?

 

[mattl]

If your old parts worked but just didn't keep the temp right, use a VOM and check to see if the contacts act the same, or simply wire in the old parts and see if the oven works as usual.  Using an Ohm meter will quickly tell you the story.

 

If the only thing you did was swap out the thermostats, then they have to be the culprit.  Switching to a different brand may yield the same results.

 

[customline]

You can't believe it.............

I found the problem. Neutral wire inside the back of the oven connected to the house neutral was loose and touching the metal access plate, thus sending extra current to where it shouldn't be !!!!! Also, don't get rid of your old Hotpoint oven transformers if you are restoring. The center tap has a certain voltage coming out of it that powers up the "Roast Right Meat Thermometer" and you will be hard pressed to find a new transformer that has a center tap like this. Oven and Roast Right meat probe accessory are doing just fine now. New thermostats are keeping good temperature. I'll have this unit installed and photos in a couple of weeks. Thanks to all the AW members who took the time to help out with advice.

 

[circlew]

Kevin, I'm glad you found out what was wrong, and corrected it. I was thinking it had to be something to do with the neutral. We had a poor neutral connection one time in our service panel - no lights or 120 volt appliances worked, but water heater and electric baseboard heaters (240 volt) would operate OK, as they don't have a neutral connection.

 

[customline]

Thank yew !!!!!!!!

Appreciate the kind words. I knew it had to be simple, right? Thank goodness that extra 240 volts didn't destroy anything. I'll be making Thanksgiving dinner it !!!!!