power cord plug melting

DrewE wrote:

fla-gypsy wrote:

Canadian Rainbirds wrote:

Lynnmor wrote:
It sounds like he is plugging in to a 30A outlet. The 30A breaker (if there is one) would trip if he is drawing more power than his equipment is rated for. The real problem is likely high resistance at the plug due to either a burned plug or receptacle.

My thought too. (It's happened to me!)

Low voltage can result in burnt plugs also

Not directly. Low voltage causes some things (most notably the air conditioner) to use more current, which causes more power dissipation in a poor connection, which causes more heating. But that's the result of increased current flow, not of the voltage of the source. Many loads consume less current at lower voltages; heating elements and light bulbs are in this category.

Melting and burning are caused by localized heat, which is caused by localized power consumption. Electrical power consumption, in watts, is voltage (across whatever is consuming the power) multiplied by applied current. A poor connection, whatever its cause, has a higher resistance than it should, leading to a larger voltage drop, and so more power consumed at that point. If you have a 2V drop at 20A, say, it matters not whether the supply is 120V (and the load proper sees 118V while the bad connection sees 2V) or 12V (and the load sees 10V while the bad connection sees 2V). The bad connection has to somehow sink 40W of heat in either case.

While your technical explanation is correct and the time spent explaining it enlightening, I surmised the OP who claims to know little about electrical didn't need a detailed explanation and a burnt plug is still toast regardless of the role the voltage drop played it its demise directly or indirectly. A serious voltage drop can result in the OP's problem, the end result being the same.