Myth? SSRs fail in the CLOSED state?

[Walker]

Yes, I was only joking. I assumed the smiley would convey that fact.

I do NOT endorse dry firing your heater element.

 

[Reelale]

Yes, I was only joking. I assumed the smiley would convey that fact.

I do NOT endorse dry firing your heater element.

Damnit.

 

[Walker]

oh... for you, reelale, i strongly suggest it. go for it.

disclaimer: i am joking again.

 

[McCuckerson]

oh... for you, reelale, i strongly suggest it. go for it.

disclaimer: i am joking again.

Without a smiley face? OK, now I'm confused

 

[Reelale]

oh... for you, reelale, i strongly suggest it. go for it.

disclaimer: i am joking again.

Seriously, I wonder if most of these failures are the result of amp draw on 220 vac elements? Or is it equal opportunity? I only use a 110 vac 1500W in a RIMS tube. I'm scared now. I have the alarm working to de-activate the signal on overshoots, but that doesn't do any good when the SSR is not answering the phone.

 

[lschiavo]

Seriously, I wonder if most of these failures are the result of amp draw on 220 vac elements? Or is it equal opportunity? I only use a 110 vac 1500W in a RIMS tube. I'm scared now. I have the alarm working to de-activate the signal on overshoots, but that doesn't do any good when the SSR is not answering the phone.

Good thing we are not building nuclear weapons

 

[Walker]

now.... maybe I can finally get back to brewing.

 

[Scut_Monkey]

Oh you installed those all wrong. It's going to break as soon as you try to brew on it. Do you have a picture of the entire CP internals?

 

[motobrewer]

mechanical relays ftw!

plus, who doesn't love the clicking!?

 

[Walker]

Oh you installed those all wrong. It's going to break as soon as you try to brew on it. Do you have a picture of the entire CP internals?

I don't have one with all the latest additions that I did to it. Will snap one later. It ain't pretty.

I recently added a float switch to my kettle to cut the SSR control signal when the liquid level is too low, a toggle to bypass the float (that's part of some future plans I have for this thing), and now these fans. I haven't completed the wiring on the fans because they need as 12VDC power supply. I tested that they worked with a wall-wort, and now the plans are to install that wall wort inside of the panel.

 

[Hugh_Jass]

Seriously, I wonder if most of these failures are the result of amp draw on 220 vac elements? Or is it equal opportunity? I only use a 110 vac 1500W in a RIMS tube. I'm scared now. I have the alarm working to de-activate the signal on overshoots, but that doesn't do any good when the SSR is not answering the phone.

I had one fail on an electric smoker I built. It uses 110v@1500W. I walked away for an hour. When I returned, the heat sink had melted through my control box :shock:

Felt fortunate there was not more damage.

Had to finish the pork in the oven.

 

[Walker]

I had one fail on an electric smoker I built. It uses 110v@1500W. I walked away for an hour. When I returned, the heat sink had melted through my control box :shock:

Felt fortunate there was not more damage.

Had to finish the pork in the oven.

That sucks.

I forgot to mention that I also hat a little collateral damage. A little indicator lamp that I was attached to the output of the SSR was fried at some point. I've got a replacement in a box somewhere, but the light never worked as intended due to the leakage current that the SSR let through, so I am in no rush to put the other one in.

 

[NiteOwlBrewing]

Methinks I have a faulty/defective SSR. The very first autotune I had on my HLT it WAY over shot and was heating even though the output LED on the PID AND the SSR test LED were not lit. It seems to happen every first heating cycle. Then, I turn off my contactor (which resides in my system prior to the SSR) and back on and it behaves ok. I've since updated the input to the SSR (and switched its duty from HLT to kettle) with a wall wart and the same thing happens. I turn off the signal input and it stays closed. Guess its time to drop another $12. Has anyone else seen this?

 

[86turbodsl]

I have Crydom SSR's driving my home's lighting system and I can state without question that SSRs can fail closed. My symptoms were lights that won't shut off. Replace the SSR, and problem fixed. I had this happen when the output was shorted to ground. Always remove power first when working on SSR's.

 

[ekjohns]

Walker what PID are you using and can you better explain how you have the fail safe connected. I would like to use mine for sous vide but am worried about the SSR failing while I am at work

 

[vindee]

That sucks.

I forgot to mention that I also hat a little collateral damage. A little indicator lamp that I was attached to the output of the SSR was fried at some point. I've got a replacement in a box somewhere, but the light never worked as intended due to the leakage current that the SSR let through, so I am in no rush to put the other one in.

A 1 microfarad 250v capacitor across the terminals of the light will snuff out the leakage current from the relay when off.
Steve

 

[jeffmeh]

Since it appears that nobody has explicitly stated it in this thread, ruining one's beer by overshooting on the mash, or having to scrap one's brew day, are minor nuisances compared to the worst case scenario if you have 20+ amps of live current without knowing it. It is very good safety practice to switch a normally open, 2-pole contactor, controlling both hot legs, between the SSR and the element. That way one knows that off means off (OK, technically both the SSR and contactor could fail open, but that is highly unlikely).