220V Power Cord Problems

I was brewing today on my eBIAB system and noticed a hot/melting plastic smell near the spa panel. I touched the cord and it was warm to the touch. I finished up the brew day, dissembled the L14-30 connectors on each end of cable and found the following:

Spa Panel Side





Control Panel Side





The cord is 4/10, and my system consists of a 5500W element, Chugger pump, and Auber PID. The Spa Panel is a 50A GFI breaker, and the main panel has 30A breaker. Neither breaker tripped, and there doesn't appear to be any melted wire or other oddities in the control panel itself. Any idea what could have caused this? I am thinking I might just have to replace the 4/10 cable with a 4/8 cable.

I'm not sure - but - it looks like you are using crimp on wire lugs. If that is the case, you need to solder the wire into the lug to insure a good electrical connection.
This is often a problem with a high current set up and crimp on terminals.

Thanks for the insight P-J. The connectors have two metal plates for each conductor. The conductor is inserted in between the plates, and then the screw is tightened to compress the conductor, securing it and making an electrical connection. I could try to flow some solder into connection to secure it even more.

After I posted this I started checking some of connection inside of the control panel, and it looks like one of the hot legs was a little loose. But it was the other hot leg (red), not the one that melted (black.)

EDIT: Also I should mention that the black leg is the one I pull all my 120V runs from.

Not sure what PJ is talking about with crimp on lugs.

Looks to me like you put the wires into the terminals that have pressure plates to tighten down, which is the intended way to do it. It also looks like one of the wires is kinda balled up which makes it hard to get a good connection, very common problem.

On the next one try to keep the wire straight and be sure to tighten very well.

Go Back & Check ALL Electrical Connections For Tightness, You Will
Find Others Have Loosen Up From Orignal Installation, This Is a Common Thing.
This Is Were PM (Preventive Maintenance) Of Your Electrical Equipement Is Important. Including Your Grounds.
After You Have Completed Your Check, You Will Notice This For
Future Reference.

If Your Comfortable/Experienced, Check Your House Breaker-Box.
You Most Likely Will Find Some There As Well.
***********IMPORTANT ******************
Turn OFF Main Breaker 1st, Remove Breaker Panel Cover
DONOT ATTEMPT THE MAIN BREAKER ***HOT *** SIDE !!!!!!!!
One-Side Of Main Breaker Is ALWAYS HOT
With Main Breaker OFF, Check w/Meter, Make Sure Circuit Is Dead !
Then Proceed To Verify The OTHER Breakers & White Wires/
Neut-Wires and Ground Bar Wires.
When Completed w/All Checks, Re-Install Panel Cover.
Step To One-Side Of Panel, DONOT Stand In Front Of Panel,
Turn Main Breaker Back On.
Take Your DMM Meter Goto a Outlet, Have Meter On AC, Insert
Meter Test Lead Into The Ground, Take Other Lead To Netural Wire Side Of a Duplex Outlet, Should Have ZERO Volts-AC, If You Have
20+ AC Volts You Might Have a Floating Ground, Usually The Ground Bus Bar Is Not Bonded w/ Netural Bus Bar, If You Understand This
Most Likely You Will Know How To Correct This, If Not Get a Friend Electrican From Work To Help or Call a Electrican.

Thank you PLC-Guy, DaleHair and P-J. I am going to buy some new connectors and re-use my current cable after stripping back some new conductors. I am going to recheck all my connections in the control panel and spa panel, and verify I have a good ground. Thanks for your help, I'll let you all know how it turns out.

Be sure to cut the wire back so that it is still very flexible and not burnt. On one end that may be 4-5 inches and the other may only be 1 inch.

Make sure only copper is in the clamping mechanism and no insulation is being inserted. Otherwise a poor connection can be the result which can reduce voltage to the appliance and heat up at high current.

Make sure you cut back to shiny copper.
Make sure your strip length is the same as shown on the back of the plug/connector.
Use the largest screwdriver that fits the screws properly.
It sure looks like you are close to it's max amperage, so I would check those connections often until you are comfortable they are staying secure.

It is a runaway situation once the connection gets hot.

'da Kid

The cause of this is very obviously a loose terminal on the black wire.
A 10/4 SO cord is sufficient for your load. Also if it were an over current issue you would have seen evidence of it all the way through the conductor not just at the point of connection.
An example of an over current event with your SO cord would have resulted in the entire length of the wire burned. I have seen cables burned where the conductor spirals (or twisted) through the cable burns the outer jacket in the same way.
Your 8/4 cable will be plenty big enough but I don't think it will fit in the lugs of the plug. You will need to change out to a 50 amp plug and receptacle.
You have a 30amp plug and a #8 wire is rated at 50amps @ 75 deg.
Let us know what you end up with.
Steve