Melting Wire?

[bknifefight]

I have been using my electric brew setup for over a year now. Recently I opened up the control panel box to show a friend and we saw some melted wire on the Black Wire between the Contactor and the Outlet for the Element.

I snipped the wire below the melt, stripped it back, added a new connector and attached it to the contactor again. It was good for a few brew sessions. On my last brew, I was keeping my eye on it and early on (heating my sparge water) I saw the wire connector starting to brown and smoke a little. I killed the system, snipped, stripped added a new connector and it was all good again.

Again, it is the black wire between the contactor and the outlet for the element, marked on the diagram with a star. It is a 10 gauge wire and should be more than fine to handle the current.

Thoughts?

 

[hunter306]

Which side (assuming it's one end, since you said you snipped and stripped it as a fix). If the whole wire is heating, you've got to get a larger gauge wire in there.

If it's one end specifically, I'd check for corrosion inside the connection (under the screw, etc)-- a dirty connection is a resistive connection.

 

[iijakii]

Is there any melting/burn marks on the connectors of the two terminals? I'd have guessed you didn't have a secure connection (loose, maybe crooked and only part is touching?) but since it's multiple times that seems unlikely.

I'd replace that wire-run instead of trimming it and see if it does it again. Start with the easiest thing first.

 

[bknifefight]

Thanks for the quick replies.

I guess I wasn't 100% clear. The melting is happening where the black wire is connected to the contactor. Because of the smoke/melt, the contactor connection point is black. I could probably remove it and scrub off the soot and make it nice and clean again. I have marked the location of the burn/black/soot on the contactor here:

I will remove the entire wire and replace it to see if that helps.

 

[iijakii]

Try just putting the wire-end under the screw instead of muckin' with terminals.

 

[bknifefight]

Try just putting the wire-end under the screw instead of muckin' with terminals.

With an all new wire, or just snip and strip the one I have?

Edit: Also, would you just stick the wire there or just a ring connector?

 

[FastTalker]

10AWG should be fine for 30A. hunter306 is probably correct--it's probably a poor connection. Consider leaving the connector out. Maybe you aren't getting a good crimp. Connectors generally aren't necessary and just another point of failure. And it's always a bad crimp when there is a failure. This can be caused by not using the correct crimping tool for the connector.

Is your main breaker actually 30A? It should eventually be tripping if you are indeed overloading the circuit.

 

[iijakii]

I'd do a new wire personally.

 

[bknifefight]

New wire under the screw coming right (after I get off work) up! Will report back next Friday after my next scheduled brew day.

Thank you all for your suggestions and advice.

 

[hunter306]

New wire under the screw coming right (after I get off work) up! Will report back next Friday after my next scheduled brew day.

Thank you all for your suggestions and advice.

very confident this will solve your problem. I'm betting that simply putting it under the screw assuming that terminal is clean is going to be the key.

Good luck!

 

[Bill_in_VA]

Is it stranded or solid? If solid switch to stranded. If you are already using stranded try crimping AND soldering the connector on.

Sometimes you can get a voltage drop across a connector like that. Example: 2V drop across crimp and connection X 30amps would be 60 Watts of point load heat...

 

[bknifefight]

Is it stranded or solid? If solid switch to stranded. If you are already using stranded try crimping AND soldering the connector on.

Sometimes you can get a voltage drop across a connector like that. Example: 2V drop across crimp and connection X 30amps would be 60 Watts of point load heat...

Stranded. It seems like a lot of people are anti-connectors. I will take off all 4 of the slip-on connectors on the contactor and put them all under the screws.

 

[Bill_in_VA]

Stranded. It seems like a lot of people are anti-connectors. I will take off all 4 of the slip-on connectors on the contactor and put them all under the screws.

Agreed. I only use crimp connectors where I have to. Just adds another connection to heat up from voltage drop.

 

[bknifefight]

Just an update for anyone who was curious. I used the contactors screw to clamp down the wire. Since then I have done two brews and have not had a single issue. I believe the crimp for my connector must have been bad, as was suggested. Thank you everyone.

 

[processhead]

Slip on connectors are convenient, but are also prone to overheating in certain applications.

I would limit the use of these connectors to circuits carrying less than 10 amps.
Using the screw down terminal on the contactor will solve your problem