PID Help

[mcgimpkins]

So I build a PID modeled off of this thread. I bought the following parts and assembled them:

AGPtek® 1/16 DIN Digital PID Temperature Controller SNR & Alarm SNR

Aluminum Heat Sink for Solid State Relay SSR Small Type Heat Dissipation

Sodial 250V 25A Temperature Control Solid State Relay

I have them wired as follows:

Whenever I turn up the temperature threshold so that the SSR turns on the voltage shoots up to 120 volts of electricity. (As it should.)

Whenever I have the temperature set low with the light "off" on the SSR I receive 75 volts of electricity

I was using the multimeter to make sure that the device shut "off". Is this normal? Do I have something set wrong? Is my SSR defective? Is my PID temp controller defective? It seems like if the temperature has risen to the level I desire it to the voltage should drop off to around 0 volts so that there is no longer heat going to the heating element.

Thanks for any help you can give.

 

[Bobby_M]

It is how SSRs work. Put a load on it and it will act as expected.

 

[trimixdiver1]

It is how SSRs work. Put a load on it and it will act as expected.

As Bobby said, it will float voltage if there is no load present. One other thing to remember, just because there is no input signal doesn't mean there is no voltage present as stated. So when working in the panel, you must isolate power to the SCR! Or you will become the load.

 

[mcgimpkins]

Thanks guys, displaying my electrical ignorance. I was under the impression that I should be getting no volts and was worried I had messed it up.

 

[trimixdiver1]

Thanks guys, displaying my electrical ignorance. I was under the impression that I should be getting no volts and was worried I had messed it up.

That's what we are here for, to help each other out.