Minimum allowed drop on ac voltage

RoyB mentioned that he uses the plugin analog AC voltmeter, one must remember that this meter sometimes needs to be set or calibrated with a known good voltage source. I have one but the MH bounces so much that it goes out of calibration occasionally . When I arrive at my destination and set up and hook up shore power I get the Fluke out and match it to the meter. You use the small slotted screwdriver in the slot at the bottom of the meter to match voltage. Digital voltmeters are much nicer, but are much more expensive. JMT

Assuming a 1500 watt heater running at 104 volts, it would be drawing about 10 amps. Further assuming an end-to-end drop of 16 volts (120 down to 104), there would be 160 watts of loss in the form of heat. If that's distributed over a long wimpy extension cord that isn't coiled up, there might not be a problem. If much of that heat is being generated in a high resistance connection or coiled-up cord, it could be enough to start a fire. Personally, I'd want to replace the assumptions with real numbers, and I wouldn't tolerate the risk of an interconnection that generates that much heat.

Where is it 104 volts?

If you are in an RV and you are measuring at an outlet OTHER than the one the heater is plugged into. 104 is below the minimum ALLOWED voltage which by the way is 105, But odds are you won't have problems as the only motor is a small fan motor and it is a bit more forgiving than say... The compressor on your air conditioner.

If you are measuring at the heater (The heater plugged in to an extension cord) no problem at all.

NOTE: a bigger extension cord might help.. My heater connects to the park with 12ga all the way. (Or one A/C does, depending on which is needed, same cord in fact) You will not plug anything other than the heater into that outlet by the way.. Special plug needed. (My choice).

Lowes, Home Depot, K-Mart, Sears all carry 12ga extension cords.

I got my last one at Ollie's Bargains.

Converters will properly function on voltages between 105V-130V AC

Circuit boards in fridges, water heaters will properly function on voltages between 10.5V-15.4V DC

LCD/LED TVs can properly function on voltages of 90V to 290V AC

Motors......stay above 108V AC

The title should be maximum drop. I hope the OP checks this soon as something is probably melted by now.

There are a couple of problems with the plug in volt meters pictured in a previous post. I have checked several with a calibrated meter and they were at best off by 2v. Also the green "Safe Range" is not the 10% + or - range.

There are really two answers to the question.

First one-- will it harm the heater-- NO.

Will it harm other 120 VAC devices you are also running-- certainly possible.

Resistance heaters are NOT voltage sensitive. But many PC boards ARE.

The good news is that most devices will tell you their voltage range if you look in the specs.

Anything below 108 volts will damage circuit boards, fridges, A/C, TVs, and power converters. It will also cause cords to get hotter and damage plug/receptacle.

Surge Guard Protectors with High and Low voltage protection trips at 132V HI and at 102V Lo.

Resistive type devices (heaters, elements) are OK with 104V

Inductive type devices (motors) can be damaged below 108V (due to the higher amp draw)

Run your space heater.
OR use a bigger gauge extension cord and run it
Just check for overheating at plug/adapters from outlet to rig

bob@29154 wrote:
It drops to around 104 volts when using. Will this cause any problems?

Yeah.. check the plugs and see if they're heating up. My bet is that they are! You're probably using an extension cord that's too small and/or too long.