Minimum allowed drop on ac voltage

I suspect you may using a extension cord not rated high enough for your use. My 50-foot extension cord plugged into my 120VAC 20AMP Garage receptacle is a HD 10-GUAGE Contractor (10-3) type extension cord.


I have used a 12-gauge size but would definitely NOT go any smaller than this. The RED ORANGE WALMART specials are usually 14-16 gauge size which will give you too much voltage drop especially for a 1500WATT heater.

I also always used the long dogbone type RV30A-15A adapter between the 50-foot extension cord and the RV 30AMP trailer shore power cable. The smaller black round RV30AMP adapter always got hot on me and may burn up rather easy.


I do not use these styles of adapters


You do not want your 30AMP Shore Power to end up like this photo - trust me...


Inside the trailer I like to use one of these RV 120VAC plug-in voltmeter. These have the SAFE ZONE marked in "GREEN" which you can glance at to make sure the 120VAC is within it correct level.


My 120VAC 15-20AMP Garage shore power connection story... This is what works great for me...

Roy Ken

Dick_B wrote:
I'm no expert (flunked out of Electrical Engineering) but the normal range of voltage is +/- 10% which is 108 volts.
My guess is that it will not cause any problem with your electric heater since it is mostly a resistive load (as opposed to a motor load) BUT I'd be more concerned as to why such a large voltage drop. Could it be that the wiring to the heater is too small ie. 14 gauge instead of 12 gauge, etc. or old or the connections are not good?

x2

120v devices are designed to operate safely at + or - 10% so 108v to 132v is the safe range.

what is the voltage with the heater off? plug it into another outlet (not in the trailer) and what is the voltage there? I would guess either a loose connection in a plug somewhere, or you are on a VERY long (and possible to small) extension cord.

If it is just a heater, 104 won't hurt it, bot there may be other things in the trailer that don't like that low voltage - I would trip the rest of the breakers, and google the specs on your converter to see the minimum required voltage.

Moved from Forum Technical Support

I'm no expert (flunked out of Electrical Engineering) but the normal range of voltage is +/- 10% which is 108 volts.
My guess is that it will not cause any problem with your electric heater since it is mostly a resistive load (as opposed to a motor load) BUT I'd be more concerned as to why such a large voltage drop. Could it be that the wiring to the heater is too small ie. 14 gauge instead of 12 gauge, etc. or old or the connections are not good?