SSR vs EMR

I usually use mechanical relays but I thought that this new project may be a better fit for a solid state relay. Basically I will be shifting a solenoid pretty continuously to control a valve. I've read that SSR can last 10's to hundreds of times times longer than EMR.


What are some.of the issues I am going against? Will there be leakage on the SSR that keeps the coil of the solenoid energized? Coil is 24 volt 1.8 watt. Does.keeping the SSR energized for long periods of time have a negative effect? I've read stuff about temperature. This is a normal nema4x enclosure with no vents mounted in a building where temps range from 30-90 deg f.

Just trying to get some opinions on if this is a good use case for SSR vs EMR.

SSRs leak a small amount of current, as in miliamps, so it would not be enough to energize that solenoid or keep it energized, but you will be able to read a voltage on the output when it's off with a digital multi meter, so just be aware of that. The heat output is 1-1/2W per amp going through it. So 1.8W/24V = 0.075A, which means 0.11W of heat, nothing to get excited about here unless you have dozens and dozens of them in a panel all on simultaneously. Just make sure the SSR is for an inductive load, meaning it will have an RC snubber across the SCR to deal with the inductive kickback when you turn the solenoid off.

I use the A-B high density terminal block style relays frequently for small solenoids; the 700-HLS1Z24 is my preferred unit with a screw-terminal base.

Yes, they leak a small amount of current; 2.2 mA is noted somewhere in the datasheet. That shouldn't bother a pneumatic valve.

I just installed a system with 220 of them on a machine with hundreds of 30-year-old 24 volt, 8 watt pneumatic valves. The box of spare relays is still sealed.