Hello. I´m making a heat treatment oven with 2 heating elements. The PID controls a solid state relay. The question is I need to regulate one of the heat element with a dimmer (I already tried and works nice)



I´m going to connect everithing like that



But I´m not sure it this setup is OK. Since I don´t really know how a SSR works I´m not sure if the dimmer can make interferences with the SSR or the other heat element. What do you think?

Thank you

best regards

 

It will work.
However, a phase-fired dimmer makes lots of interference. I would suggest that you use proportional control, where the heater switches on for complete mains cycles.

 

Thank you!

 

See Fairchild App note AN-3006 for zero cross switching style Triac driver, Advantage is Less surge current and no EMI generated.
As per post #2.

 

See Fairchild App note AN-3006 for zero cross switching style Triac driver, Advantage is Less surge current and no EMI generated.
As per post #2.

If you already have zero-crossing SSRs, all you need is a comparator to drive the SSR LED, with a thermistor on one input and a reference on the other. No need for hysteresis.

 

The question is ........
If You already have a PID-Controller,
then why do You need a Dimmer on one Element ?
Do 2 Heating elements running together pop a Circuit-Breaker ?
.
.
.

 

thanks for your answers.

LowQCab, because I made the oven, and later I realised that it needs more power, buuuuut I don´t have room for a propper long coil, so I had to put a shorter coil of kanthal wire. It´s only 16 ohms and I´m using the dimmer I can to drive only with 6 amps

 

OK, got it .......
Do the Elements produce enough Heat-Output when connected in Series ? .......
Just a thought.
.
.
.

 

It is not only that, this oven is going to be used most of the time at 500 ºC to stress relieving in homemathe triode valves. But sometimes I´ll use it for hardening steel so I want the other coil separate of the rest of the circuit so I can turn on only when I need it, but thank you for your interest