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Crydom SSR

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markn

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Hello Folks,

I am using a Cydom D2W202F relay to turn a 120VAC solenoid valve on and off for a shot time. The specs for the relay say that it is a TRIAC type and is controlled using a 3_30 VDC signal. The problem I am having is that the relay conduct regardless of whether there is a control signal or not, I have six of these relays hooked to a common line voltage with the outputs seperated into six seperate terminals. What am I doing wrong?
 
You say its for a solenoid and then mention relay. was that a typo?

how are you triggering the ssr? where does the control signal come from? have you verified that the trigger falls below the "must turn off" voltage to turn it off?

are you sure you are using AC for the solenoid? If it's DC, the TRIAC won't shut off. Do you have back emf diodes?
 
Markn, looking at the specs there is a 2Amp limit (constant). Have you included a snubber circuit as the SSR should turn off at the 0V point of the cycle but if there is sufficent back EMF maybe thats holding it up, remember solenoids are inductors.
 
When you say conduct all the time are the solenoids operating or are you measuring a voltage output. SSRs will have some leakage and the specs show 8mA of leakage current and if you used a voltmeter to check the output it would show 120V, this is normal, you need to test the output with a load (solenoid or lamp).
 
Problem identified

Hi Guys,

I thought I would share what I have learned. Basically I choose the wrong SSR, it requires a larger load the I am using (i.e. 1/2 watt solenoid coil) 40 to 60 watts. Unless there is a load of this size connected, the TRIAC will leak and conduct. I was also told to use a random turn on vs a zero crossing type.
 
put a 60 watt light bulb in parallel with the solenoid. for your application, I'd think you want zero crossing. random will product rf interference though probably not that much. I'd think random is really just for phase control (dimming, for example) applications.
 
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