Need a SSR suggestion to use with 4 actuators


i want to use “one” SSR e.g. “Sharp S 202 S12” to control 4 combined actuators

Sharp S 202 S12
NovaDrive NC 230 V

Any suggestion/warnings/informations on doing this in the long-run.

Do i need cooling or something? I never used a SSR on a daily base. Any Help is appreciated.


I few months ago I made some Imp AC switches with SSRs. I really like using them despite the cost. The most important thing to remember in my opinion is that some are made to switch inductive loads, and some resistive. There is a pretty long thread on the subject.

My major concern is to not burn the house down :wink:

I need to do more research on it, but the circuit containing the SSR that was turning my christmas tree on and off did get hot enough to brown the white enclosure. I do NOT know if that was the SSR or some other issue in my circuit though. I need to run it with the cover off and find out.

@chrischi I’ve done this with novaDrive like heating actuator. I used the 24v which is both AC/DC controlled. I used a mechanical relay but the Sharp looks good.

You want to control all 4 heads with one SSR? assume this for a manifold in one room with multiple wet loops?

The valve actuators take 0.6 A for max. 100 ms at 230V so aprox 2.4 Amps for 100ms. I’m not an electronics guy but I don’t think the imp can’t supply enough current to switch on the SSR
Minimum trigger current 8mA think the imp supplies 4mA?
Also look like max forward voltage is 1.4v on the opto imp supplies 3.3
It looks like so you will need a FET or transistor to drive it.

Hopefully others more able than me can help on this.

thx guys for all the good informations.

right! It is for a manifold in one Room with multiple loops.

I missed that the the forward voltage is max 1.4 on the SSR. Damn…

Maybe i find another SSR like the Sharp. I’am still concerned about the
produced heat of SSRs. Actually i didn’t need to mind about things like that,
because i use a small servo to change the adjustment wheel of my heating
control. :wink:

I found some SSRs on Digikey that only need about 3mA to switch. They are NOT cheap… I think they were CUI, but you dont need any other components in the mix… the module switches them nicely.

Chrischi, the Sharp SSR you refer to is a little different from what hobbiests typically refer to as an SSR. That is a component meant for PCB mount.

I used the Sharp device in a project that I did with imp but my load is purely resistive so there was little concern about the snubber circuit.

I used a BJT transistor to drive the SSR from the imp.
Looking back at my notes, I had written the following:

NPN BJT Transistors used to drive diodes in SSR
4.7k current limit resistors for the base
100ohm current limit resistors for the SSR drive LED
20mA is drawn by each SSR with this configuration (to switch it)

One way to know is to try it! Just be careful with your high-voltage safety.