Solid State Relay (SSR) not shutting off

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shadowrayz

shadowrayz

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Joined
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Hello Everyone ~
I have recently built a control panel for my HERMS brewing system and having an issue with my Solid State Relays. Here are the specifications of the setup:

- Dedicated 240v 30a circuit to garage
- Circuit terminates to a Spa Panel (GFCI Breaker) with recepticle for control panel plugin.
- I am using The Auber DSPR120 (one for the HLT and one for the BK)

I am a computer geek of over 30 years and just dangerous enough to work with electricity. I would not say I am heavily versed otherwise I wouldn't be here.

I have bought a new 40a relay from a very well known company. I powered up and the following is ocurring:

I set the DSPR into MASH Mode and play with the temperature so you can see the out light firing. The SSR matches the pulse (LED). I check the voltage output on the element connector with my multi-meter and I have voltage to the element connector. Now, when I set to under the current temperature, the out light on the DSPR120 and the SSR go out. I place my multi-meter on the output to the elements, it is still showing 240v. This issue happens on the boil setting as well.

Am I not getting something here? I am at my wits end with troubleshooting this. :confused:

I have attached part of the schematic that shows how I have it wired. Thank you to doug293cz.

Much appreciated and thank you all in advance.
Cheers!

Single.jpg
 
From your description, it sounds like the SSR output is shorted in the on state.
As a sanity check, lift the wire connection from terminal 3 (or 4, doesn't matter which) of the SSR) and see if the power to the element goes off or stays on. Disconnect all wires with power off as a safety precaution.
If the element remains energized with the control signal disconnected, then the SSR is bad and will need to be replaced.
 
I have no personal experience with one failing. I seem to recall more reports of them failing closed by others on the forum.
Anyone else here able to confirm that?
 
Is the heating element connected when you are measuring the voltage? Is it getting hot when it should not?
What about the pilot lamp? Does it respond to the on/off command?
 
OK - I tested with disconnecting the 3 or 4. The SSR LED is out and the connector for the heating element is reading 240 volts. I do not have a heating element connected.
 
beermanpete said:
Is the heating element connected when you are measuring the voltage? Is it getting hot when it should not?
What about the pilot lamp? Does it respond to the on/off command?
Click to expand...

On the DSPR120, the "power out" LED is NOT on. The SSR does not show the LED on. The circuit is still being made as I read 240v at the element connector. I do not have the element hooked up at this time. Oh, and yes, the SSR responds when the "power out" LED is on and off on the DSPR120. Visually it looks good from the LED standpoint but it is still powering when it shouldn't.
 
Up until you said you actually tested with the heating element I was going to say, ssrs leak voltage and you have to test them with an actual load or they will show voltage even when off.
 
augiedoggy said:
Up until you said you actually tested with the heating element I was going to say, ssrs leak voltage and you have to test them with an actual load or they will show voltage even when off.
Click to expand...

Here is the deal - I did some additional testing after I wrote my last post.

I did a basic SSR test with a lamp of 40 - 100 volts.
I put the lamp inline to the SSR and then used a 9 volt battery to activate the SSR.
Guess what? The SSR works. Now I am really confused.

:confused:

I tore out all of my wiring in my control panel so I could focus on one circuit at a time. This is NUTS!

Any suggestions?
 
Operating the SSR under full 240 volts with the element may be causing it to break down under the heavy load.

You could connect the SSR back in your panel and connect the 9 volt battery as a control voltage source. Check how the SSR acts under full load with full voltage.
 
What brand and power rating SSR's are you using? What kind of heat sink to you have for your SSR's, and exactly how are the SSR's mounted to the heatsinks?

If the SSR works with a small load, and gets stuck "on" when working with the full load, it may be latching up if it gets hot. SSR's can get hot if the heatsink mounting is inadequate.

Edit: As mentioned by others, SSR's leak a small amount of current when off (a few mA.) This causes a voltmeter to see the full voltage potential even when the SSR is off, if the SSR doesn't have a low impedance load connected to it. This is why you can't properly test an SSR without the load being connected.

The leakage current is why you should also have a mechanical switch or contractor to provide a positive disconnect for the voltage to the SSR as part of your control circuit.

Brew on :mug:
 
Last edited:
Hey I'm not really understanding your explanation, but I do work on electronics for a living and seeing what you wrote, a couple things come to mind. First reading 240 at the output says to me the circuit is open i.e. "Off". If the circuit is closed, "On" I would expect to see a voltage that is less than max. The other thing is that solid state stuff has to have certain voltages to work right. If a switch closes there is often bounce. A switch bouncing can make your device not work. Anyway probably no help but may be something to look at.
 
Its not so much the voltage as it is the amps load... I was confused too the first time I used mine.. The first ones I ever used were the crappy knock off fotek ones and those leak terrible. Enough were my indicator light on my old panel would light up when off by the pid but the selector switch was on if nothing was plugged into the element plug.
 
shadowrayz said:
Here is the deal - I did some additional testing after I wrote my last post.

I did a basic SSR test with a lamp of 40 - 100 volts.
I put the lamp inline to the SSR and then used a 9 volt battery to activate the SSR.
Guess what? The SSR works. Now I am really confused.

:confused:

I tore out all of my wiring in my control panel so I could focus on one circuit at a time. This is NUTS!

Any suggestions?
Click to expand...
yeah it sounds like you discovered that you need a load to test... Are you absolutely sure your element kept heating before with the ssr light off? They will often overshoot the temp you set them for a bit depending on setting and temp probe placement so you cant go by that.

Also dumb question but your sure you have a 40a AC ssr and not one for dc right?
 
Thank you all.
I will continue checking after work today and let you all know my findings.
 
doug293cz said:
What brand and power rating SSR's are you using? What kind of heat sink to you have for your SSR's, and exactly how are the SSR's mounted to the heatsinks?

If the SSR works with a small load, and gets stuck "on" when working with the full load, it may be latching up if it gets hot. SSR's can get hot if the heatsink mounting is inadequate.

Edit: As mentioned by others, SSR's leak a small amount of current when off (a few mA.) This causes a voltmeter to see the full voltage potential even when the SSR is off, if the SSR doesn't have a low impedance load connected to it. This is why you can't properly test an SSR without the load being connected.

The leakage current is why you should also have a mechanical switch or contractor to provide a positive disconnect for the voltage to the SSR as part of your control circuit.

Brew on :mug:
Click to expand...

Hi Doug ~ I will get you the specifics of the parts when I get home later today.
 
processhead said:
Operating the SSR under full 240 volts with the element may be causing it to break down under the heavy load.

You could connect the SSR back in your panel and connect the 9 volt battery as a control voltage source. Check how the SSR acts under full load with full voltage.
Click to expand...

The control from the DSPR120 isa 12V DC signal. I will try using the 9V DC battery when I get it hooked back up. I will let you know.
 
augiedoggy said:
yeah it sounds like you discovered that you need a load to test... Are you absolutely sure your element kept heating before with the ssr light off? They will often overshoot the temp you set them for a bit depending on setting and temp probe placement so you cant go by that.

Also dumb question but your sure you have a 40a AC ssr and not one for dc right?
Click to expand...

He got it from Ebrew supply.. I don't think they sell DC versions.. Very bad luck to to have 2 go bad..?!?!
 
shadowrayz said:
The control from the DSPR120 isa 12V DC signal. I will try using the 9V DC battery when I get it hooked back up. I will let you know.
Click to expand...

The ebrew SSR should work with the auberins controller. it from the same manufacturer as Aubrins usesebrew just has the labeled differently.. they are both mager SSRs..
 
Hello Everyone~
I had not been able to update until now as I have been busy with some after-hours work and could not get the time in to test.

I just finished testing with the SSR and here are my findings:

Go to 14:00 in my video I posted yesterday and you will see the test of the SSR with a number of 40W lights and it works perfectly with a 9 volt battery.
[ame]https://www.youtube.com/watch?v=ss5e1VFZVvc&t=860s[/ame]

Today, I had a chance to fill my BK above the element to do some testing - Here we go:
- I was able to control the element with a 9 volt battery.
- I hooked the DSPR120 up and the MASH setting and Boil settings worked perfectly.

I am stumped! All of this troubleshooting and the SSR checks out good? UGH!!!!

Now, to put the control panel back together and do some more testing...

Bugs, Bugs, Bugs!

This thread is not done....

Thank you everyone! ;)
 
It's your PID. There's a setting where once boil temp is reached, the ezboil beeps then allows you to manually back off the power to the heating element. Before it beeps, even if you turn down the power to 0, it still will power up full tilt until designated boil temp is reached.
 
ZmannR2 said:
It's your PID. There's a setting where once boil temp is reached, the ezboil beeps then allows you to manually back off the power to the heating element. Before it beeps, even if you turn down the power to 0, it still will power up full tilt until designated boil temp is reached.
Click to expand...
His original problem was kind of the opposite of yours.... The element didnt turn off but instead kept heating after his set temp point was reached..
 
augiedoggy said:
His original problem was kind of the opposite of yours.... The element didnt turn off but instead kept heating after his set temp point was reached..
Click to expand...

It's not the bAST setting I'm speaking of, it's the btSP or bALH....not sure which one that is but set both values down to right below the boiling temp

My problem ended up being Blichmanns BoilCoils suck for rolling boils, lol
 
ZmannR2 said:
It's your PID. There's a setting where once boil temp is reached, the ezboil beeps then allows you to manually back off the power to the heating element. Before it beeps, even if you turn down the power to 0, it still will power up full tilt until designated boil temp is reached.
Click to expand...


shadowrayz's original description of the issue...

I set the DSPR into MASH Mode and play with the temperature so you can see the out light firing. The SSR matches the pulse (LED). I check the voltage output on the element connector with my multi-meter and I have voltage to the element connector. Now, when I set to under the current temperature, the out light on the DSPR120 and the SSR go out. I place my multi-meter on the output to the elements, it is still showing 240v. This issue happens on the boil setting as well
Click to expand...

The OPs panel symptoms are not consistent with a bad PID.
 
ZmannR2 said:
It's your PID. There's a setting where once boil temp is reached, the ezboil beeps then allows you to manually back off the power to the heating element. Before it beeps, even if you turn down the power to 0, it still will power up full tilt until designated boil temp is reached.
Click to expand...

Great Point! I will check on that.
Cheers!
 
shadowrayz said:
Hello Everyone ~
I have recently built a control panel for my HERMS brewing system and having an issue with my Solid State Relays. Here are the specifications of the setup:

- Dedicated 240v 30a circuit to garage
- Circuit terminates to a Spa Panel (GFCI Breaker) with recepticle for control panel plugin.
- I am using The Auber DSPR120 (one for the HLT and one for the BK)

I am a computer geek of over 30 years and just dangerous enough to work with electricity. I would not say I am heavily versed otherwise I wouldn't be here.

I have bought a new 40a relay from a very well known company. I powered up and the following is ocurring:

I set the DSPR into MASH Mode and play with the temperature so you can see the out light firing. The SSR matches the pulse (LED). I check the voltage output on the element connector with my multi-meter and I have voltage to the element connector. Now, when I set to under the current temperature, the out light on the DSPR120 and the SSR go out. I place my multi-meter on the output to the elements, it is still showing 240v. This issue happens on the boil setting as well.

Am I not getting something here? I am at my wits end with troubleshooting this. :confused:

I have attached part of the schematic that shows how I have it wired. Thank you to doug293cz.

Much appreciated and thank you all in advance.
Cheers!
Click to expand...

Something on this diagram doesn’t look right to me. You appear to be switching only L1 with the SSR? For a 240v setup, shouldn’t you be switching both L1 and L2? Unless I’m misreading it and you are actually driving a 120v element, but the contactor setup suggests otherwise.
 
thomash said:
Something on this diagram doesn’t look right to me. You appear to be switching only L1 with the SSR? For a 240v setup, shouldn’t you be switching both L1 and L2? Unless I’m misreading it and you are actually driving a 120v element, but the contactor setup suggests otherwise.
Click to expand...

It is unnecessary to switch both legs on a 220 volt element. Switching only one leg is normal and typical.

The element is in series with both legs and the SSR. Open one leg and the element is switched completely off.
 
Ok, just my ignorance showing. It was my general understanding that a 240v circuit is actually two 120v loads out of phase with each other. But I guess I should have known better seeing that the plug is missing a common wire. Always more to learn...
 
thomash said:
Ok, just my ignorance showing. It was my general understanding that a 240v circuit is actually two 120v loads out of phase with each other. But I guess I should have known better seeing that the plug is missing a common wire. Always more to learn...
Click to expand...

You are correct about the absence of the common wire, or more correctly here, the neutral wire.

In an application where you are using 220 volts and the neutral, you generally need to switch both L1 and L2. A typical residential central A/C system condenser unit would be an example where that happens.
 
processhead said:
It is unnecessary to switch both legs on a 220 volt element. Switching only one leg is normal and typical.

The element is in series with both legs and the SSR. Open one leg and the element is switched completely off.
Click to expand...

processhead said:
You are correct about the absence of the common wire, or more correctly here, the neutral wire.

In an application where you are using 220 volts and the neutral, you generally need to switch both L1 and L2. A typical residential central A/C system condenser unit would be an example where that happens.
Click to expand...
To expand a little bit on the above:

For 240V split phase power control, you only need to interrupt the current flow. Since current always flows in a loop, you can stop current flow, and power delivery, by switching only one of the hot lines. However, when you switch only one line, the load still has voltage on it, even though no power is being supplied. To remove all voltage from the load, you need to interrupt both hot lines, with a mechanical (air gap) switch. I believe code requires this for the main on/off switching of 240V equipment.

SSR's don't completely interrupt the current flow, just reduce it to a few mA, or less, which is enough to drop the power delivery close to zero, since P = I^2 * R. Drop the current by 2 to 3 orders of magnitude, and you drop the power by 4 to 6 orders of magnitude.

Brew on :mug:
 
FIXED - Issue was due to lack of knowledge... :(

Here is what I figured out:

Thank you to ZmannR2 on making my brain look at troubleshooting the DSPR120.

ZmannR2 said:
It's not the bAST setting I'm speaking of, it's the btSP or bALH....not sure which one that is but set both values down to right below the boiling templ
Click to expand...

- After calibrating the temp probe in ice water, I was able to get the EZBoil setup correctly with the temp.

- Going into the MASH and BOIL setting, I adjusted the bAST, Boil Acceleration Set Temp to 195 from 200. (my boil occurs at 198 at my altitude).

- That specific adjustment made the system function correctly. I double-checked with my other DSPR120 and tested for about two hours doing different things.

I appreciate all of your help. It came down to finding quiet time to go over the documentation a few hundred times and then test.

YOU ALL ROCK! \m/ :mug: CHEERS!
 
doug293cz said:
To expand a little bit on the above:

For 240V split phase power control, you only need to interrupt the current flow. Since current always flows in a loop, you can stop current flow, and power delivery, by switching only one of the hot lines. However, when you switch only one line, the load still has voltage on it, even though no power is being supplied. To remove all voltage from the load, you need to interrupt both hot lines, with a mechanical (air gap) switch. I believe code requires this for the main on/off switching of 240V equipment.

SSR's don't completely interrupt the current flow, just reduce it to a few mA, or less, which is enough to drop the power delivery close to zero, since P = I^2 * R. Drop the current by 2 to 3 orders of magnitude, and you drop the power by 4 to 6 orders of magnitude.

Brew on :mug:
Click to expand...

My wiring was spot on - It was an issue with DSPR adjustment. All is good now. Thanks for the schematic!

:)
 

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