smoke coming from eBIAB panel

[virgil1]

I was getting my brew ready to go. Sanitizing my silicone lines to my pump, water was in the kettle, had the probe hooked up, PID was reading 55 degrees or so, so it was reading ambient temp in my garage as I didn't have any liquid flowing across the probe yet. I had 8 gallons of water in the kettle. I had the box on because I wanted it to fire on the heating element while I finished sanitizing my silicone pump lines. I ran up stairs to give my kettle lid a good scrub, and when I came back down I smelled some burning, and saw some smoke coming out of the panel. I shut it off immediately. It was coming from an connection to the contactor. One of the 120V lines in that goes directly to the contactor. Needless to say I halted the brew day while I research my best course of action. An idea:
1. I had turned on the heating element, and the probe was just measuring the garage temp at the time. So it was 'always on'. The PID was set to 150 degrees. It wasn't seeing any change in temp so it wasn't flipping on and off. I think it usually flips on and off, and having it 'on' for so long exposed a 'not so great connection' I had from my inlet to my contactor.

Any other thoughts? Do I just need to replace the wire that melted a bit, and make sure the connection is ok, or should I replace the contactor too? They are only $10, but I am not sure there is anything wrong with it.

Here is my build:
https://www.homebrewtalk.com/showthread.php?t=538782


Thanks!

 

[virgil1]

Added some pictures.

 

[FastTalker]

It may be a loose connection at the contractor. A loose connection has a high resistance which will cause heat to be generated which will start to melt plastic and insulation. Make sure that connection is snug.

 

[FastTalker]

Added some pictures.

That's definitely what it will look like if you don't have a good connection. Make sure all the strands are under the terminal too.

 

[wilserbrewer]

Why are you sanitizing your pump lines pre boil?

The mash is NOT sanitary, so equipment used for the mash doesn't typically get sanitized.

Equipment post boil needs to be sanitary.

 

[raouliii]

I agree with the loose connection diagnosis. If you decide to reuse the contactor, I would suggest opening it up to check the condition of the contacts and clean them. The heat may have had an effect on them. FWIW, I always use a NOALUX compound on copper to aluminum connections, which combats aluminum oxidation.

 

[virgil1]

You guys are all awesome. I didn't expect such quick responses. I run star san through my pump lines before I start. Probably overboard, but I do. I will replace the wire and check the contactor. It is probably a bad connection. I might look into a spade terminal connection there instead of just the wire. I was lazy and ran out of spade connectors at the time. I'll open up the contactor and take a look too.

 

[UndeadFred]

Ghetto as it sounds, if it isn't melted all the way though, I would tighten her down and then replace later (or even remember insulate later with heat shrink) and brew on... I am mobile now and can't assess damage on the little screen but that isn't dangerous in the short term..

 

[UndeadFred]

It looks like it arced at connection because it was loose.. If so clean it up, tighten it up and carry on.

 

[BrunDog]

I think you should not re-use that contactor. In fact, even though this appears to be local overheating from a loose or corroded connection (not arcing), I would suggest you replace the entire high side path. Just because you lost one connection doesn't mean the others are sound. You were just short of a fire - don't take it lightly.

 

[UndeadFred]

Inspect the contactor before you replace it. Watch it the next time you use it. If you had a fire in that metal box it would not have gone very far anyway. Common sense here .

 

[jekeane]

Back to the sanitizing your silicone lines thing. While there is nothing wrong with it there is literally zero benefit of sanitizing anything pre-boil.

 

[raouliii]

.... I might look into a spade terminal connection there instead of just the wire. I was lazy and ran out of spade connectors at the time. I'll open up the contactor and take a look too.

The type of connection on the contactor should not have any crimp connections on the wires. Strip the insulation, insert into contact block and tighten, making SURE that no insulation is clamped into the connection. This last thing could have been a contributing factor in the initial problem.

 

[trimixdiver1]

Wow this happened again! Did you use one of those cheap multi tool crimpers, if so, get a real crimper and re crimp all connectors.

 

[virgil1]

I took the top off the contactor, and cleaned it up. I used a bit of sandpaper and some WD-40. I put spade connectors on the two hot wires from the 240V inlet to the contactor. I also put them on the 'outbound' side of that contactor. It all works fine now. I still want to put spades on the 2nd contactor as well. Doing that tomorrow. I did a quick test with about 7 gallons of water and just brought it up to 100 degrees. No issues. Contactors didn't even get warm(just the SSR heat sink did as usual).

 

[BrunDog]

This is why meltdowns and fires happen. I fear the day someone ignores common sense, violates rules, and has a real catastrophe.

 

[trimixdiver1]

I took the top off the contactor, and cleaned it up. I used a bit of sandpaper and some WD-40. I put spade connectors on the two hot wires from the 240V inlet to the contactor. I also put them on the 'outbound' side of that contactor. It all works fine now. I still want to put spades on the 2nd contactor as well. Doing that tomorrow. I did a quick test with about 7 gallons of water and just brought it up to 100 degrees. No issues. Contactors didn't even get warm(just the SSR heat sink did as usual).

Seriously????? You had a fire in that panel and you don't think replacing the contactor is a good idea? The amount of heat generated at that failure point will weaken the metal and change its property's. You will have another fire, count on it if you don't replace the contactor and the affected wiring.

To top it all off you sanded the lug down with a flammable oil.

By the way

It's LINE and LOAD, not inlet and outbound.

 

[virgil1]

The type of connection on the contactor should not have any crimp connections on the wires. Strip the insulation, insert into contact block and tighten, making SURE that no insulation is clamped into the connection. This last thing could have been a contributing factor in the initial problem.

What's the reason for no crimp connections? It has spade connections (4 on each connection): http://amzn.com/B001KGSJ74

It seems like the crimp connection would have less chance of an issue, but I am no expert.

 

[virgil1]

Seriously????? You had a fire in that panel and you don't think replacing the contactor is a good idea? The amount of heat generated at that failure point will weaken the metal and change its property's. You will have another fire, count on it if you don't replace the contactor and the affected wiring.

To top it all off you sanded the lug down with a flammable oil.

By the way

It's LINE and LOAD, not inlet and outbound.

Thanks, I will replace the contactor. This is why I posted in the forum, I am no expert. Any advice on using the spade connectors or the screw terminal? I felt like that is where the problem was. Thanks again.

 

[virgil1]

This is why meltdowns and fires happen. I fear the day someone ignores common sense, violates rules, and has a real catastrophe.

Thanks for the advice and comments. I am no expert. I will replace the contactor.

 

[UndeadFred]

I will be the dissenting electrical engineer again. You had a loose connection. It arced. Either the contactor would be damaged or it would not have. I think continued use would have been okay. You have it in a metal box, you would have tripped a breaker before that box would have caught something else outside of the box. Crimp really well or crimp and solder both or use the screw terminal. I would lean towards the screw terminal though..

 

[atoughram]

Thanks for the advice and comments. I am no expert. I will replace the contactor.

I've seen equipment at work run for years and years after a similar failure where a contactor lug got hot - I wouldn't bother replacing the contactor. As long as the contacts inside are good and not melted and the body of the contactor isn't melted, I'd believe it's fine. Get yourself an infrared thermometer (http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-60725.html) and check the temperature of the lugs while it's under load - they shouldnt be different from side to side.

Now high current though crimp connections is asking for trouble.

 

[trimixdiver1]

If the lugs are too big to properly secure and make good contact with the wire then you need to get smaller lugs or a larger gauge of wire. But also watch out so it will fit in your twist loc sockets.

Originally I don't think it was terminated, just wired to the lug. Might be wrong.

As others said, don't use crimp on connectors unless you have to, and then only if you have a real crimper, not a multi tool.

 

[virgil1]

If the lugs are too big to properly secure and make good contact with the wire then you need to get smaller lugs or a larger gauge of wire. But also watch out so it will fit in your twist loc sockets.

Originally I don't think it was terminated, just wired to the lug. Might be wrong.

As others said, don't use crimp on connectors unless you have to, and then only if you have a real crimper, not a multi tool.

I have a real crimper. Bought it based on recommendations from folks on homebrewtalk.
Its this one:

http://amzn.com/B0069TRKJ0

 

[virgil1]

I've seen equipment at work run for years and years after a similar failure where a contactor lug got hot - I wouldn't bother replacing the contactor. As long as the contacts inside are good and not melted and the body of the contactor isn't melted, I'd believe it's fine. Get yourself an infrared thermometer (http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-60725.html) and check the temperature of the lugs while it's under load - they shouldnt be different from side to side.

Now high current though crimp connections is asking for trouble.

No plastic melted anywhere. Just the wire insulation on the one wire where the loose connection was. I think I'll still order a new one. It's only $10. Better safe than sorry.

 

[atoughram]

I think I'll still order a new one. It's only $10. Better safe than sorry.

Hold on to the old one for a backup.

 

[FuzzeWuzze]

As you stated, replace it with a spade connector going into the contactor instead, the screw down terminals IMO should only be used as a last resort if you need 5 connections. While not difficult, it is the easiest connection to screw up if its not tight or your on some of your insulation.

You may have to reposition your contactor(and should replace!) because it looks like your so close you wont even be really able to get a spade in there without touching the outlet since the spades your using are rather long.

 

[virgil1]

As you stated, replace it with a spade connector going into the contactor instead, the screw down terminals IMO should only be used as a last resort if you need 5 connections. While not difficult, it is the easiest connection to screw up if its not tight or your on some of your insulation.

You may have to reposition your contactor(and should replace!) because it looks like your so close you wont even be really able to get a spade in there without touching the outlet since the spades your using are rather long.

FuzzeWuzze! Thanks! I built a BrewPi controlled keezer thanks to your awesome thread! I am going to take it all out and move the contactor forward, good eye. I was able to get the spade connector in, but it was super tight. Will move out so it's easier(and not so tight) when I get the new contactor in. $10 seems like a worthwhile investment.

 

[BrunDog]

I will be the dissenting electrical engineer again. You had a loose connection. It arced. Either the contactor would be damaged or it would not have. I think continued use would have been okay. You have it in a metal box, you would have tripped a breaker before that box would have caught something else outside of the box. Crimp really well or crimp and solder both or use the screw terminal. I would lean towards the screw terminal though..

I can't help but rebut pretty much your whole post:

1. I doubt it arced... Just overheated from high resistance from a loose or corroded interface.

2. It would be damaged or not. That's correct. But just because it is damaged doesn't mean it won't work. Maybe it will work forever, maybe just a few more uses. I can drive my car into a tree, and it may still drive after. But that doesn't mean the frame's not bent. Anyway, for a $10 part, what risk that is worthwhile?

3. Being in a metal box means what? It's impervious to fire?

4. Why do you think the breaker would have tripped? Breakers trip in over current situations... Just because there is a portion of the circuit that became an unintended heater, that doesn't mean the breaker will trip. If I throw a wad of newspaper into a toaster oven and turn it on, once the fire erupts inside, is the breaker going to then trip?

5. Generic terminals should not be crimped then soldered. Heating them effectively eliminates the integrity of the mechanical connection. There are certain limited terminals which are designed to be crimped then soldered.

You should be careful giving out free advice... You are potentially putting lives at risk.

-BD

 

[UndeadFred]

The metallic boxes will contain arcing or melting wire. The wire eventually would have burnt though, causing an open (self limiting) or a short which would then trip the breaker. There isn't really anything in that box as fuel. The contactor probably had the same structural integrity as it did originally since it doesn't look like it melted. If the wire got hot and didn't arc then the case for reuse is even stronger.

Honestly you guys treat this stuff like nuclear radiation. Proper grounding, a GFCI and a good insulated (or grounded metal) box and you are already safer than an electric water heater is in almost every house...

 

[UndeadFred]

The heating isn't the problem with soldered connections. It is the stiffening of stranded wires. If they flex they can crack and break. This should not happen inside of a box that has no movement. Having said that I screw down on the wires in the high current section of my box and it is perfectly fine.

 

[atoughram]

I screw down on the wires in the high current section of my box and it is perfectly fine.

X2

I've worked on multi-million dollar equipment where most of the connections were only screwed down. Remember, when adding crimp-on terminals, you add an extra mechanical connection. For every mechanical connection you have a potential failure point and a spot that will potentially heat up depending on the quality of the crimp.

 

[UndeadFred]

I am going to add, what should be replaced is the wire that melted, or at least heat shrink tubing should be put over it to reinsulate it. The contactor still seems OK to me.. It is more like I hit the tree with the quarter panel of my car and cracked the headlight lens, so I should not drive it for an analogy. Certainly if it was something I was repairing for someone else I would replace the contactor, but for me.. I would maybe order another at my convenience and get around to it when I had extra time.

 

[virgil1]

I am going to add, what should be replaced is the wire that melted, or at least heat shrink tubing should be put over it to reinsulate it. The contactor still seems OK to me.. It is more like I hit the tree with the quarter panel of my car and cracked the headlight lens, so I should not drive it for an analogy. Certainly if it was something I was repairing for someone else I would replace the contactor, but for me.. I would maybe order another at my convenience and get around to it when I had extra time.

Thanks! I did replace the wire. New contactor is on order already. Should arrive this week(along with a new baby girl, but only one of those is coming from Amazon).

 

[UndeadFred]

Which one? Enjoy the kid..

 

[itsnotrequired]

Thanks! I did replace the wire. New contactor is on order already. Should arrive this week(along with a new baby girl, but only one of those is coming from Amazon).

congrats! #3 arrived for me just three weeks ago (baby, not a contactor:fro. let me tell you, my brewery build has slowed waaaaaaay down...

 

[akthor]

Exactly.

I will be the dissenting electrical engineer again. You had a loose connection. It arced. Either the contactor would be damaged or it would not have. I think continued use would have been okay. You have it in a metal box, you would have tripped a breaker before that box would have caught something else outside of the box. Crimp really well or crimp and solder both or use the screw terminal. I would lean towards the screw terminal though..

 

[BrunDog]

or at least heat shrink tubing should be put over it to reinsulate it.

More dangerous advice. Not sure why one would remove one end of a damaged wire to "reinsulate it" rather that remove both ends and discard/replace the wire. This is inane. Unfortunately, because it's on the internet someone will believe this is acceptable or safe practice.

 

[itsnotrequired]

More dangerous advice. Not sure why one would remove one end of a damaged wire to "reinsulate it" rather that remove both ends and discard/replace the wire. This is inane. Unfortunately, because it's on the internet someone will believe this is acceptable or safe practice.

replacing the entire piece of wire may be 'better' but repairing with tubing can be 'acceptable or safe practice'. repairs with shrink tubing are made all the time in the industrial world for these types of incidents. if doing a shrink repair, it is important to use an appropriate tubing, one with a ul listing that has a voltage rating. also need to prepare the conductor and apply the tubing in accordance with the manufacturer's instructions. installed in such a manner, the tubing repair is totally fine. the problem comes in when joe homeowner is using some cheap tubing off of ebay or not installing it in the correct manner.

i'm with you though, i would replace the entire conductor for such a short length and small gauge.

 

[BrunDog]

You have no idea what damage was done to the wire's conductors. I challenge that covering it up is safe practice. That said, I have said my peace and will exit this thread.