SSR relay problem solution

[mdkmdk]

So is the SSR switching as it should now? That is, is it on when it has a voltage between 3 and 30VDC at its input?

The oven should reach 800 degrees centigrade in about two hours, when I took the measurement with the multimeter the oven was on.

 

[DPG]

The oven should reach 800 degrees centigrade in about two hours, when I took the measurement with the multimeter the oven was on.

So the SSR is working correctly then?

The fault must be elsewhere. Have you got a wiring diagram for this oven?

 

[mdkmdk]

So the SSR is working correctly then?

The fault must be elsewhere. Have you got a wiring diagram for this oven?

I don't know, from the input measurements with the multimeter it would seem so, unless it was sent to me faulty.

 

[DPG]

I don't know, from the input measurements with the multimeter it would seem so, unless it was sent to me faulty.

You can't tell from the input measurements alone - you need to make sure it operates (ie switches on) when the input voltage is present.

 

[mdkmdk]

You can't tell from the input measurements alone - you need to make sure it operates (ie switches on) when the input voltage is present.

How can I do to understand if it switches on?

 

[DPG]

How can I do to understand if it switches on?

I think this is beyond your abilities. You've already changed lots of items, and modified the oven with a heatsink. If you don't know how to test if the SSR is working then it is going to be difficult to advise further.

To be honest, if you had the same fault (not reaching full temperature) before and after changing the SSR then I can't believe it is faulty. Unless of course something is overloading it, such as a short circuit somewhere. But this is the problem when you approach fault finding by just replacing individual items.

 

[James]

Any electrical engineer should have the fault found within an hour, probably less than half an hour.

 

[marconi]

Please would you tell me the make and model number of the oven so that I can look up its details? Or even better send me a picture of its specification plate.

 

[mdkmdk]

Please would you tell me the make and model number of the oven so that I can look up its details? Or even better send me a picture of its specification plate.

Unfortunately there is no plate in the oven showing the manufacturer and the model of the oven, however it should be an oven built in the 90s.

 

[marconi]

Unfortunately there is no plate in the oven showing the manufacturer and the model of the oven, however it should be an oven built in the 90s.

Sorry, but without this information I cannot help you.

 

[Tim Evans]

If the oven is heating up at all (even if not to the desired 800 degrees), then the SSR must be operating. It sounds more like either a control issue (either not set to a high enough temp' or perhaps misreading the thermocouple) or an issue with the heating element itself. Perhaps the heating element (thru aging or damage) has increased in resistance and now cannot heat beyond a certain temp?
Can you measure the resistance of the heating element? (Obviously only do it with the oven safely isolated & unplugged from the power, and also unplug the element before measuring so you are only measuring the element and not any other parts of the circuit)
Tim

 

[DPG]

If the oven is heating up at all (even if not to the desired 800 degrees), then the SSR must be operating. It sounds more like either a control issue (either not set to a high enough temp' or perhaps misreading the thermocouple) or an issue with the heating element itself. Perhaps the heating element (thru aging or damage) has increased in resistance and now cannot heat beyond a certain temp?
Can you measure the resistance of the heating element? (Obviously only do it with the oven safely isolated & unplugged from the power, and also unplug the element before measuring so you are only measuring the element and not any other parts of the circuit)
Tim

I've a feeling he might have already changed it - not sure if that's what he means when he says he has replaced the 'resistance '

 

[mdkmdk]

If the oven is heating up at all (even if not to the desired 800 degrees), then the SSR must be operating. It sounds more like either a control issue (either not set to a high enough temp' or perhaps misreading the thermocouple) or an issue with the heating element itself. Perhaps the heating element (thru aging or damage) has increased in resistance and now cannot heat beyond a certain temp?
Can you measure the resistance of the heating element? (Obviously only do it with the oven safely isolated & unplugged from the power, and also unplug the element before measuring so you are only measuring the element and not any other parts of the circuit)
Tim

The resistance has been changed and tested correctly by a technician, the thermocouple, SSR relay and temperature controller have also been changed, the temperature of the temperature controller has been set to a minimum of 200 degrees and a maximum of 800 degrees centigrade. The problem of rising temperatures was already there before all these pieces were changed.

 

[mdkmdk]

I've a feeling he might have already changed it - not sure if that's what he means when he says he has replaced the 'resistance '

All resistance was changed in the internal ceramic chamber by an experienced technician.

 

[DPG]

You need to take this to someone who can repair it for you. Did you pay the 'experienced technician' for the work he has done so far?

 

[mdkmdk]

You need to take this to someone who can repair it for you. Did you pay the 'experienced technician' for the work he has done so far?

Yes, I paid for it. I was able to have him replace the resistance because I took out the inner part of the oven and then reassembled it, unfortunately I can't bring him the whole oven.

 

[Tim Evans]

What happens when you set it to heat? You said that it only gets to 100 degrees, but does it just maintain 100 degrees until you turn it off, or does it turn itself off at that temp and then cool itself down?
(edit to add does it consistantly and repeatedly only heat to 100 degrees each time you try?

 

[mdkmdk]

What happens when you set it to heat? You said that it only gets to 100 degrees, but does it just maintain 100 degrees until you turn it off, or does it turn itself off at that temp and then cool itself down?
(edit to add does it consistantly and repeatedly only heat to 100 degrees each time you try?

For example today I tried it twice, the first time the temperature stopped rising to 88 degrees, the second time to 356 degrees after 1 hour. When the temperature stops rising, the oven lights stay on, the oven is on, only it stops heating.

 

[Tim Evans]

Does the controller give any indication of either error code or that it is still trying to heat? or does it just display the "goal" temperature or the temperature that it thinks it is? And have you measured the temperature independantly of what the Controller says?

 

[Tim Evans]

(just thought of a couple more questions)
Can you tell us what the make and model of the Controller is?
Can you post some more pics? (photo of the display of the controller at power on, and when it stops heating)

Also how good is the themal seal around the door? (perhaps there is some damage to insulation somewhere and more heat is escaping than the heater can replace )

Tim