Solid State Relay Switch Needed


Thread Starter


Hey Guys,

I have a heating plate that I use in the lab here in UWO. It has stopped working and I believe I have traced the problem to a solid state relay switch. The heating press company is out of business and I can't get the part through them.

The writing on the switch states that it is a Picker CMPTS, Solid State Relay, Type PCh410-S-09,

Do I have to use this EXACT relay "on a PCB made by ACT CORP. Rowett, TEXAS"

or can it be substituted for something else?

ANY help you can give me will save me. Thanks.
You can replace the Solid State Relay by another with the same specs.

A solid state relay is just a switch which can be switched ON or OFF by a control voltage. The control voltage can be 24 volt or 110 v or 220 volts. check what is the control voltage in your case. The other side will be the power side. This is specified in volts and load amps. Once you know this you can buy the required Solid State relay in the market, from any manufacturer. Popular brands are CRYDOM, OMRON, EUROTHERM....

Hope this information helps.


Phillip Knobel

The relay can certainly be replaced but you need to examine it for mechanical and electrical properties that will enable a substitute. What voltage and current, what input control voltage, what physical configuration, etc. Once this is known it will be possible to pick a close match.

Good Luck!

Matthew Hyatt

I believe that you can get the exact SSR from, they have all the picker SSR products and such. Or do a search on Solid State relays, there are several vendors who carry these relays. I found 20 that I could call and get the relays from in a 1 minute search. Also look up solid state relays on, and get a relay with the same exact ratings.

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Yeasir Rahul


The component you mentioned is not a solid state relay, it is a normal (electro-mechanical) relay. Its datasheet is at

In general you do not need to replace a relay with an exact product. Different brand/model with similar ratings would do.

You need to match the voltage and current ratings of the contacts. These are 10 Amps @ 120 VAC. Coil voltage is to be matched also, which is 9 volts in your case. Less important is matching the coil impedance. Anything in the same order should be fine.

Now you have to lookup product charts of different manufacturers/suppliers, and decide yourself. Hope this helps.

Yeasir Rahul
System Integration Consultant
VoltSmith Technologies

Michael Griffin

If the solid state relay is a conventional type, you should be able to replace it with something compatible fairly easily. SSRs are commodity items.

Someone asked this same question a couple of months ago. Look in the message archives for: Solid State Relay Switch Feb 1, 2004 11:53 am, by N2framing. Or just try

A reply to that message stated the web site for Picker was

If you find the specs for it, you can probably get something compatible from Electrosonic or someplace similar. You need the current rating, maximum output voltage, and input voltage.

Michael Griffin
London, Ont. Canada
No, there are many substitutes that will provide equal or better performance.

All of the information that you need to know should be printed on the relay such as: control input, maximum amps, and maximum volts.

Contact our tech support office and they'll find a proper replacement for you.

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I did a google search, and found a very interesting thread right here in the AList forum.

In that message someone with an identical problem received an answer on how to get to the Picker website where a replacement can be obtained, and also other responses showing that any part with equivalent specifications can be used.

Took a look, and see that Picker doesn't show any CMPTS series relays, but they do have a PCB solid state relay - PCD240AC8 - closely matching the part number from the earlier post.

This is a very common "hockey puck" relay rated 250V line at 40 amps, 4-32 volts DC input, and with zero-crossing. It can be obtained through just about anybody - Crydom, and Opto 22 spring to mind. If a substitution were to be used it is usually OK (and almost always better, in terms of reliability) to go with higher line voltage (480 or 600V) and higher current rated devices.

You may want to call Picker directly, and find out if the slight difference in part number is significant - the only thing I can think of that would mess up the works is if the original part used random turn-on (as opposed to zero crossing) switching.

Doug Sherman

I would not go as far as saying that a solid-state relay is a commodity item, as there are slight differences between each manufacturers relays. However, most applications will accept various manufacturers products without experiencing any technical difficulties.

The two most prevalent manufacturers on the market today are Crouzet (formerly Gordos) and Crydom. The Crouzet substitute for the Picker relay is their 84134020 (240VAC) or their 84134120 (480VAC). Crydom's p/n would be D2450 or D4850. However, the Crouzet relay is a better designed product.

You can compare specs on these products by visiting their websites;