charred common (white) connection on 30-50 plug

[robkathybat]

While disconnecting my 50/30 plug from the electric box, I noticed the common stab was charred around the stab and the stab was discolored. I took the 30/50 plug off the 50 amp plug and the common stab was charred around the base and the stab was discolored on the trailer cable. I've replaced the 50 amp plug on the camper cable and ordered a new 50/30 amp plug. My question is does the common wire see the same amperage that the hot wires do? My trailer 50 amp cable is original and had never caused me any problems before, and I check the other cables every time I use them. I am not sure why this would suddenly happen.

 

[mgolla]

The neutral line sees the same amperage as all the 120v loads. The char shows the outlet connection is loosening and the outlet needs to be replaced

 

[shiggs]

White common wire current.

On a 30 amp connection, the common wire and prong should have the same current as the only hot wire or prong.

On a 50 amp connection, the common wire or prong should have zero current as the two hots are 180 degrees out of phase making the common return cancel if the two hot are balanced. In real life the common should be the difference between the two hots.

If the common current is the sum, the two hots are the same phase and the outlet is incorrectly wired.