Solid state relay question again

Had replaced one of the my2j eletromechanical relay on my equipment's circuit board earlier. The function of this relay is to give a signal to start another equipment. Machine was running fine a while ago but it's showing problem nowadays. a signal is sent to start the other equipment although the conditions had not been satisfied. This problem did not exist until now. How can i solve the problem?

You can try to provide more info (relay make and part#,
type of load, load rating, suppresor type, wiring...).
It looks like relay output is shorted. Since it used to
work, you have to consider all options...

Solid state relays are not suitable for all mechanical relay applications. If the old relay was handling say, 120VAC to turn on a thing, then the solid state version is just fine. Your description

The function of this relay is to give a signal to start another equipment.

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is a little confusing but if you meant that the old relays were being used with their contacts dry(no voltage applied to them from an outside source), then the solid state device is not going to work correctly. If as panic mode suggested, you have placed a solid state relay in a circuit that is overloading or placing higher voltages than the device is rated to handle, you may indeed have burned it out or shorted as the case may be. Tell us more about you app and why you changed the old relays in the first place.

Solid state relays are not suitable for all mechanical relay applications.

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NO they arent but not by the example you used, dry contacts arent no voltage/no current...they may be low voltage/current. They dont offer all the contact options electromechanical relays do but they offer more and more every day, they offer 2 and 4 pole but not always in the mounting package you need.

I have used Crydom SSR's in many applications, they are rated from milliamps to over 100 amps with voltages ranging widely over AC/DC. Control voltage also ranges over a wide spectrum of AC/DC.
They offer 1 to 4 poles and 3 phase.
They offer din, panel and PCB mount.
NC or NO
Turn ON: Phase controlled, random, soft-start, zero-cross and time delay.

They cost more....yes.
Are they reliable...definitely yes.
Do they eliminate many issues that are inherent when using electromechanical relays....again definitely yes.

Ron,

You mentioned NC or NO,

That was interesting, so far I have never come across any solid state relay with NC contact (connection). Can you please give more info, I did look at your link, but couldn't fine any,

Thank You

A mistake?

Well, we are all fallible! Good thing no one is getting paid to give advice or help here or on other well meaning forums.

But I stand by my original statement:

Solid state relays are not suitable for all mechanical relay applications.

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Chavak if you goto Crydom.com then click on Solid State Relays it offers choices on Search criteria...choose NC as the criteria and any other choices you need.

Here is an example of an SSR with a NC option, read down to options...FORM B is NC

Randy I was not attempting to critique...just offering info.

I appreciate your non paid assitance on this site and any other that for unknown reasons is non-accessible at this time.

rsdoran said:

I appreciate your non paid assitance on this site and any other that for unknown reasons is non-accessible at this time.

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I think you're just gettin' too popular Ron...

Either that, or Randy has launched a DOS (meaning Denial Of Service, not Disk Operating System) attack on your server...

beerchug

-Eric

hey guys, the electromechanical relay on my first piece of machine (A) is a NO 24VDC relay. Across the pole is also 24VDC that is supplied by another equipment (B). Once the pole closes, terminals will be conducted and hence, a signal is given to that other equipment (B). Was using Omron MY2J before switching to Omron G3FD series.
Any suggestions?

... a signal is sent to start the other equipment although the conditions had not been satisfied ...

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it sounds like "leakage current" to me ... if so, then basically the solid state relay is acting just like a solid state output on a PLC ... you might need a bleeder resistor to "load" the circuit ... if you need more help, just do a search on this site for "bleeder" ... or "leakage" ... etc.

ken,

I just read through this thread again ... and now I’m really confused ... you started off your first post with the title “Solid state relay question again” ... and you mentioned that you had replaced an “electromechanical” relay ... that made me think that you had just taken out a “regular-old-real-contact” relay and had installed a “solid-state” type relay in its place ... if that is the case, then your problem might be caused by “leakage” current as I said in my previous post ...

but now when I look more carefully, I notice that in your last post you said:

... the electromechanical relay on my first piece of machine ...

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so which is it? ... is the new relay that you’ve just installed a solid-state type? ... or is it an electromechanical type? ...

incidentally, I tried searching the Omron website ... but couldn’t find anything for “G3FD” ... can you give us a link to the part that you're trying to use? ...

This shows and explains about Omron G3FD

This shows and explains MY series relays

The first shows that a G3FD, which is solid state, is a direct replacement for an MY series electromechanical relay.

... I'm still betting on leakage current ...

Thanks, Ron Doran,

apparently my search for “G3FD” didn’t work because the catalog uses the term “G3F/FD” for the model in question ...

I’m still guessing that our old nemesis “leakage” current is causing Ken’s problem ... and not only do we have the regular-old leakage current of this solid-state device to contend with ... the catalog (on page 5 of 8) contains the statement “Snubber circuit absorbs external surges” ... I take that to mean that this little bitty solid-state relay has a built-in suppressor circuit internally connected across its output terminals ... in my experience, these types of circuits always seem to increase the amount of leakage current ... based on all of this, I’d say that Ken might need to go right back to the old tried-and-true electromechanical type of relay to get his machine back to working normally ...

of course, a properly sized "bleeder" resistor might also take care of the problem ... here is a quick troubleshooting trick ... try installing an incandescent lamp bulb (of the proper 24 volts rating) in parallel with the "other machine's" input ... then test the operation again ... my guess is that now when the relay is ON then the lamp and the "other machine's" input will also be ON ... when the relay is OFF then the lamp and the "other machine's" input will also be OFF ... in other words, the "phantom signal" problem should be solved ... if this works, then the lamp is actually acting just like a simple "bleeder resistor" and my "leakage current" hunch would seem to be pretty well on target ...