Heating element...Pop! Boom! Bam! ...and still working?!?

Here is my set-up: 2 1500w (120v) camco stubby elements (the ones the you buy thinking they are ULWD...), one of which is connected to a PID, the other is directly connected to the wall outlet and used as needed to bring wort to a boil. I recirculate the mash through a pump and sparge arm. Everything is connected to GFCI outlets.

I Brewed my first E-BIAB (Keggle conversion) last week and during the boil, post mash, my one heating element "popped". By "popped", I mean a loud pop with a flash around the gang box. This was the element that was directly connected to the wall outlet. I unplugged it and continued the boil with one element.

After inspecting the element, wiring, and housing, all looks fine. Meaning, no loose connections, leaks, or touching wires. Last night I ran a test run, bringing water to a boil, and both elements functioned fine.

So, what was that "pop"?

My thoughts at the moment: when I milled my grain, my mill was slightly uneven and half the grain slipped through. Therefore, I adjusted the milled and put it through the grinder again. I am sure there was a lot of "flour" as a result of 2x milling. Could this have led it to dry-fire?

Whatever it is, the element seems to be functioning...and the batch of beer I brewed, at about a week into fermentation, appears (and taste) fine.

Any ideas of what this is? Should I be worried?

Thanks!

A pop and a flash in an electrical box will most likely be the result of an arc. There should be some evidence of that arc inside the box. Either a loose connection in current carrying conductors, a short to ground or a faulty component. Did the GFCI trip?

Did you used stranded wire in your assembly?
Sometime a loose wire strand can short between two terminals or a hot terminal and a grounded box, with the results you describe.

After the light show, the short clears and all appears normal. As Raouliii says, there is usually some evidence of the arc, like black soot in the vicinity of the short.

Check that your connections are tight and there are no stray strands.

Thanks for the response. The GFCI did not trip. I do recall some soot in the gang box. I'll have a look tomorrow, re-checking the connection. Appreciate your help!

Patricknobles said:

....The GFCI did not trip. I do recall some soot in the gang box....

Click to expand...

If the GFCI did not trip then the short must have occured between hot and neutral. Or the GFCI is not functioning properly, you might want to test it.

None of this sounds very good, honestly... I'm also a little concerned that you said "After inspecting the element, wiring, and housing, all looks fine." and then later said "I do recall some soot in the gang box." - soot in a gang box where you just had a 'pop' should not fit into the "all looks fine" category. And then there's the fact that the GFCI didn't trip - did you wire that up yourself? Definitely want to test it.

You're running two elements pulling 12.5amps each - are you on two separate circuits? What gauge wiring did you use in your setup? Stranded or solid core?

Your grain milling would not cause anything, unless you had enough grain flower build up to cause an explosion, which would require more than a few passes through the mill and would have been far more obvious than a pop, so I think you can safely ignore the grain milling part of things.

Do you have photos of the gang box / soot area / wiring? That would help point to a problem.

First - i opened up the gang box and there was no residue or soot on the terminals or connectors. I thought there could have been some, but it looks like it was just some JB weld from connecting the gang box to the keg. There isn't any soot on the leads or terminals.

Second - the GFCI is hardwired onto the plug from the heating element, not a kitchen outlet GFCI. I use neutrik PowerCon connectors and 12 gauge wire. It very well could have tripped and I didn't notice as I unplugged it quickly. When I plugged the cable in and powered up the element a few days later, everything powered up just fine. I imagine since I unplugged the GFCI cable and plugged it back in, it could have reset.

Tonight I am going to make sure all of my connections are "clean" and there are no loose ends.

Looks like I found the problem; see attached photo.

Ok, I see the stray strand of wire where it appears to have grounded out on the box...kind of what I expected could be the source of your problem...

But what exactly is that thing that the wires are running to? A strain relief or what?

it is Neutrik PowerCon connector.

I am re-doing all connections tomorrow to make sure there are no more "stray" wires.

Thanks to all for your help.

If you have the tools and skill, I'd highly suggest soldering your ends. That will keep any stray wires from getting out, and it will give you a better bond between the wire and your plug.

I like those plugs though - may have to look into adding them, as the hardwired nature of the element bothers me. Are they rated for the power draw you're putting through them? Got a suggested source to get them from?

These look like they are electrically rated for the application, 20 A @ 250 V.

http://www.neutrik.com/en/audio/powercon/powercon-20-a/nac3mpa-1

I am a little concerned about the lack of clearance between the grounded metal hole and the energized exposed connections you have there. You may want to consider adding some heat shrink tubing to the back end of that connector where it is nested in the threaded hole.

Like a lot of European connectors, they are very compact, which can make the wire connections a little tricky. They appear to require a crimp-on spade connector to mate up to the actual quick-connector. Might be difficult to solder these?

If it were me, I would probably have put a cord on the kettle j-box and moved the connectors to my control panel, but that's just a personal preference.

Agree - at first i soldered everything into place, but now I am going to use the push-on terminal connectors to connect to the female PowerCon. Processhead is correct, space is tight and the push-on connectors will ensure a proper fit with no over-lap of wires.

I support the idea of having the connectors on the j-box, as for when I clean-up and pack-up, everything can be put away and stored without cables hanging everywhere. Just personal preference.

badnews - I got the connectors from our favorite online shopping outlet. Can't remember which vender, some audio/electronic company from TX. Shipping was cheap and they arrived really fast. Message me if you want me to go back and look up the name of the company for you.

processhead said:

I am a little concerned about the lack of clearance between the grounded metal hole and the energized exposed connections you have there. You may want to consider adding some heat shrink tubing to the back end of that connector where it is nested in the threaded hole.

Click to expand...

Do you mean plugging up that hole so there is no possibility for current to pass though? If so, would silicon caulk work?

You might be able to do it with silicon sealant, but that would make it tough to disassemble if you ever needed to.

I would use heat-shrink tubing or just electrical tape.

Good deal. Thanks for all your help...what would I do without HBT.

Pop! Boom! Bam!