SSR relay problem solution

[mdkmdk]

Hello everyone,

I have a goldsmith oven to which I had to change an SSR relay because when it reached 475 degrees centigrade the temperature increase stopped. Since the oven must reach 800 degrees in about two hours, I have to solve the problem.

I changed all the main components to the oven: thermoregulator, thermocouple, resistance. The problem of increasing the temperature was present even before changing all these components.

I ordered an SSR relay of the same brand and model as the one mounted on the oven: Crydom D2425.

Since it was panel mounted I proceeded to modify the panel to put a heatsink in it.

Between the heatsink and the relay I put some Thermalright TFX thermal paste which has a high thermal conductivity power and is also used in computers and can withstand up to 300 degrees.

After having reassembled everything I turned on the oven, this time it reached 100 degrees centigrade after 10-15 minutes the increase in temperature stopped.

I wonder where he went wrong about the SSR relay changing as I think I've done everything possible. Could anyone help me? Thank you in advance for your reply.

I attach some photos to the message.

 

[James]

check you are getting a voltage across a1 and a2 on the ssr
without that control voltage the relay turns off.

 

[mdkmdk]

check you are getting a voltage across a1 and a2 on the ssr
without that control voltage the relay turns off.

how can i do to verify that?

 

[DPG]

how can i do to verify that?

Multimeter set to appropriate range.

 

[mdkmdk]

Multimeter set to appropriate range.

I'm not expert with the multimeter, could you explain me how to set the multimeter to the appropriate range? Thanks.

 

[DPG]

I'm not expert with the multimeter, could you explain me how to set the multimeter to the appropriate range? Thanks.

Are you using an auto ranging meter?

 

[mdkmdk]

Are you using an auto ranging meter?

Yes, it's not manual.

 

[DPG]

Yes, it's not manual.

The SSR is DC controlled. Set your meter to DC Volts

 

[plugsandsparks]

As above, set your multimeter to DC volts range so you can pick up 3-32 volts. Connect Positive lead to 3 and common or negative lead to 4. MAKE sure you are reading volts not current....
If you get a reading between 3-32V the heater should be on and stay on until the reading drops below 3V

hope this helps

P&S

 

[mdkmdk]

As above, set your multimeter to DC volts range so you can pick up 3-32 volts. Connect Positive lead to 3 and common or negative lead to 4. MAKE sure you are reading volts not current....
If you get a reading between 3-32V the heater should be on and stay on until the reading drops below 3V

hope this helps

P&S

Does the oven have to be switched on during measurement or switched off?

 

[telectrix]

duplicate thread here along with the transformer query.

 

[DPG]

Does the oven have to be switched on during measurement or switched off?

It needs to be on - you are measuring voltage.

I think you may be out of your depth with this one. Take care when making any tests etc.

 

[mdkmdk]

It needs to be on - you are measuring voltage.

I think you may be out of your depth with this one. Take care when making any tests etc.

Yes, the transformer is from the same oven as this thread (sorry if I inadvertently created a duplicate of this thread, if you see fit please delete the other thread and leave this one). Why do you think the approach of changing everything is not good? The only things left to change are the rectifier bridge and the transformer, I don't know what to do to solve the problem that seems to have a completely unknown cause.

 

[DPG]

Yes, the transformer is from the same oven as this thread (sorry if I inadvertently created a duplicate of this thread, if you see fit please delete the other thread and leave this one). Why do you think the approach of changing everything is not good? The only things left to change are the rectifier bridge and the transformer, I don't know what to do to solve the problem that seems to have a completely unknown cause.

Well I suppose it depends how much time and money you are willing to spend on it. What happens if one faulty component is damaging another? If that's the case and you keep replacing single items you will never fix it.

 

[mdkmdk]

As above, set your multimeter to DC volts range so you can pick up 3-32 volts. Connect Positive lead to 3 and common or negative lead to 4. MAKE sure you are reading volts not current....
If you get a reading between 3-32V the heater should be on and stay on until the reading drops below 3V

hope this helps

P&S

I made the measurement you suggested, the value is 22.4 v at start-up and 23.0 v when the temperature stops and no longer increases, I am attaching the photos of the multimeter set on two different ranges

 

[DPG]

I made the measurement you suggested, the value is 22.4 v at start-up and 23.0 v when the temperature stops and no longer increases, I am attaching the photos of the multimeter set on two different ranges

If that's a measurement at the SSR input then that is enough to switch it on. The 0.6V difference won't have any effect.

 

[mdkmdk]

If that's a measurement at the SSR input then that is enough to switch it on.

Yes, the measurement is at the SSR input. This time at 88 degrees Celsius it has stopped rising further, when you turn it on you can hear the hum of the resistance, when the temperature stops rising you no longer hear any hum. (The resistance has been changed and tested)

 

[DPG]

Yes, the measurement is at the SSR input. This time at 88 degrees Celsius it has stopped rising further, when you turn it on you can hear the hum of the resistance, when the temperature stops rising you no longer hear any hum. (The resistance has been changed and tested)

Well, at the voltages you are measuring there the SSR should be switched on, assuming it isn't faulty of course.

 

[mdkmdk]

Well, at the voltages you are measuring there the SSR should be switched on, assuming it isn't faulty of course.

With the old SSR relay the temperature stopped rising to 475 degrees centigrade and didn't rise anymore, but now it seems to stop rising at ever-changing temperatures.

 

[DPG]

With the old SSR relay the temperature stopped rising to 475 degrees centigrade and didn't rise anymore, but now it seems to stop rising at ever-changing temperatures.

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?