SSR relay problem solution

[marconi]

In the input of the relay and at the output of the rectifier bridge the measured direct current is 22.6 volts. When the heating process is on, the DC current measured at the SSR input is 22.3-22.4v instead when the heating process is off, it is approximately 22.6-22.8v.

So to be clear - the voltage across the ssr terminals 3 and 4 is always in the range 22.3 - 22.8 V? It never drops to zero Volts even when the heating process is Off? This is surprising and not what one would expect.

Why will you not connect the SSR to the controller's SSR output? This output is designed to switch the SSR on and off.

Could you draw a diagram of how items are connected please?

 

[mdkmdk]

So to be clear - the voltage across the ssr terminals 3 and 4 is always in the range 22.3 - 22.8 V? It never drops to zero Volts even when the heating process is Off? This is surprising and not what one would expect.

Why will you not connect the SSR to the controller's SSR output? This output is designed to switch the SSR on and off.

Could you draw a diagram of how items are connected please?

Yes, it is always in that range even when the heating is not on.
I can't fully understand how the oven works.

 

[mdkmdk]

So to be clear - the voltage across the ssr terminals 3 and 4 is always in the range 22.3 - 22.8 V? It never drops to zero Volts even when the heating process is Off? This is surprising and not what one would expect.

Why will you not connect the SSR to the controller's SSR output? This output is designed to switch the SSR on and off.

Could you draw a diagram of how items are connected please?

What if I directly connected the SSR relay to the thermoregulator using terminals 11 and 12 (currently not used since the SSR is driven by the thermoregulator through the internal relay function of the thermoregulator) of the thermoregulator?

If I disconnect all the wires of the input and output of the SSR and to the input of the SSR 3+ and 4, I connect some wires that I am going to connect to terminal 11 and 12 of the thermoregulator, while in the output of the SSR I connect directly only the wires of the resistance? It might work?

I measured the direct current at the output of terminals 11 and 12 of the thermoregulator, it corresponds to 11.9 volts. Could it be fine for the relay as there is currently 22.6 volt current in use?

 

[DPG]

I still say you are beyond your abilities here. No shame in that.

Without a wiring diagram I feel we shall get nowhere.

 

[marconi]

What if I directly connected the SSR relay to the thermoregulator using terminals 11 and 12 (currently not used since the SSR is driven by the thermoregulator through the internal relay function of the thermoregulator) of the thermoregulator?

If I disconnect all the wires of the input and output of the SSR and to the input of the SSR 3+ and 4, I connect some wires that I am going to connect to terminal 11 and 12 of the thermoregulator, while in the output of the SSR I connect directly only the wires of the resistance? It might work?

I measured the direct current at the output of terminals 11 and 12 of the thermoregulator, it corresponds to 11.9 volts. Could it be fine for the relay as there is currently 22.6 volt current in use?

Yes. Ensure correct polarity, The minimum voltage is 3V and across 11 and 12 there is 12V. ssr input has to be greater than 3 and no more than 32V.

 

[marconi]

I have attached a picture showing you how to connect the ssr to the controller. MAke sure the SSR and controller are connected with + to + and - to -.

 

[mdkmdk]

I have attached a picture showing you how to connect the ssr to the controller. MAke sure the SSR and controller are connected with + to + and - to -.

I solved the problem by directly connecting the thermoregulator to the SSR relay as you told me, now it works fine. Perhaps it was the rectifier bridge transformer circuit that failed, by directly connecting SSR and thermoregulator the transformer was bypassed. What do you think caused the failure? Before doing all this I also disconnected the thermoregulator from feeding the transformer through terminal 4, although the problem persisted, this shows that the thermoregulator works well. I also put some terminals on the connectors that I no longer use and I wrote the corresponding number on them, in case of a possible future use by fixing the transformer problem. The only thing is that it gets to 790 degrees in 2 hours and 20 minutes. I would need it to get to that temperature in 2 hours. If I put a fan on top of the SSR would I be able to reduce the time? When the oven was open and reached 500 degrees, the relay by touching it above had a temperature slightly above that of the environment. Then I had to close the panel and turn the oven to test it up to 790 degrees.

 

[James]

have you done the PID tuning?

 

[marconi]

Installing a fan will not help. Why do you have to reach 800C in 2 hours? What difference does 20 minutes more have?

 

[mdkmdk]

Installing a fan will not help. Why do you have to reach 800C in 2 hours? What difference does 20 minutes more have?

For a matter of saving time in the long cooking process of the flasks and the goldsmith casting. There are heat losses from the opening door and the hole where the oven exhaust pipe is, perhaps trying to contain them using ceramic fiber or other heat resistant materials I could reduce the time.