I have a Dacor Convection oven. W305W made in 1990. I replaced the clock control module 5 yrs. ago. The thermal sensor 6 yrs ago and both heater elements over the last few years. When my wife turned it to preheat yesterday it poped inside, and triped the main 220VAC breaker and went dead. I pulled it out of the cabent and pulled all the covers. No burned connections or shorted spots. I pulled the cover off the broiler delay relay and burnished the contacts. No burns or shorts on any pcb. When I put on bake or broil and push the + button, I hear a click (The clock contact pull in?) then a second click in 2-3 seconds (Drop out?) the heater elements get slightly warm but never hot. How do I test so I know if it is the temperature sensor or clock controller? I repaired radar in the Navy and have a volt/ohm meter. Thanks Art San Jose, California
Hi Art, thanks for using JustAnswer.com. My brother was a "nuke" aboard the USS Carl Vinson CVN-70 for many years...now to the oven. One side of the 240 VAC comes from L2 straight to the elements. The other comes from L1 to the control and through any safety stats. It sounds like the elements may be grounded to neutral causing the "slightly warm" scenario. That also could explain why the breaker popped. Do you have 240 VAC to the unit now and is the control still dead? Kelly
Highly accurate diagnostician with over 30 years experience!
Reply to Town 's Post: Nukes are a special breed. Out of my leage.
I have 240VAC to the unit. the clock and other numbers (red temp set 350)work. When I call up for 350 it will stay on the display and then go to 100. never movers above 100. art
I have to go buy cat food. Maybe later or in the AM.
Okay, it sounds like you are missing one leg of the 240 to the element....can you check for 240 VAC across the elements when the unit is turned on? Also, WITH BREAKER OFF, check for continuity through elements and from elements to ground/neutral. Let me know what you find....
I got continuity yesterday on all 3 elements: bake, broil and convection All tested approx. 0 ohms. Also measured open from lead to ground.
I have to pull the oven back out of the cabent and remove the back cover to measure the voltage on the leads.
With the volt meter on AC and one probe on the center tab on each side or the element, I should measure 240 VAC??? Maybe I'm over thinking this but if the element is a short why would I see 240?
Good night. Art
PS: I'd pay more than $9.00 but I've been out of work 6 months with nothing on the horizon. This is the first time I've paid for on line help. How do I get you when I comeback on line in the morning or do I just take who ever is on line?
I'm hoping it is not the clock/ controller because it looks like $500 for a new upgrade kit.
I'd like to fix this tomorrow if possible. How to test a temp sensor with 2 white wires? Short at room temp?
Temp sensor tested by resistance, should be about 1100 ohms at room temp if it is a positive thermal coefficient probe as most of them are. From one side of the element to the other (2 terminal element) when on should be 240 VAC. Don't stress over the $9.00, I love doing this! Just continue this thread when you arrive in the morning. I will have to be gone from about 8am-2pm or so, depending on my call load but will check in as I can. Goodnight...Kelly
Hope you had a productive set of calls. 1. The sensor measures 1080 Ohms. 2. the 3 elements are 20-30 ohms each no short to chassic or ground. 3. When I set for power on the clock to any of the elements I get 0 between the leads. 4. When the oven has house power but turned off with the main rotory switch I still have 112 VAC on one lead of the convection element and to one lead of the bake element. Spooky as I though when the rotory switch was stright up the red light is off and I thought no power to the leads. I check the main power in and have 120 and 120 on each leg and 240 acroww them. Stumped for now. Art
Okay, you are losing the power through the thermostat, or control as it may be. If you have 120 VAC to the elements with switch off, L2 is good. 0 VAC across element terminals when set to bake indicates one side of your 240 VAC is missing, and we have proven that it is the side that comes through the control. Provided there is power into the control, I would have to say the control is at fault...
like buy a new clock/controler for $350? Art
Anything else I should check before I buy the clock/controller? I found it for $305 plus shipping. Once I buy it I cannot sent it back. What does it cost in your area?
Once I accept and pay can I ask you more questions if it does not fix it?
Thanks for the help and I'll be glad to pay and give you a good rating.
You can trace voltage from L1 to control and see if you have 120 VAC into control. If you have voltage into control but not out, control faulty. I will see you through to the end of this repair, absolutely.
Reply to Town 's Post: If I pay now will the thread stay open or should I wait?
I was thinking before you order that control, can you trace the wire back from the element to the control as there may be a thermal fuse or thermostat in line with it that may be open. Just physically trace the wire back to the control if you can.