How much voltage drop is too much?

[David0858]

How much voltage drop house wiring is too much?

In my office not far from the breaker box on a 15A circuit and 14ga wire I just checked and with no load it runs 121.5v. It's running 117v with a space heater on low and using 4.75A, with the heater on medium it's 116v using 7A and on high it's 112.5v using 11.2A although the last time I checked on high it was down to 110 point something.

 

[wyliesdiesels]

5% is the nec recommended voltage drop so that would be 114v.

What else is on this circuit?

 

[sberry]

Is there anything else on it?

 

[David0858]

5% is the nec recommended voltage drop so that would be 114v.

What else is on this circuit?

Not much as there's no voltage drop until I turn the heater is on at least low. Maybe a lamp, maybe a lamp and my computer (If it is it uses very little). The wiring is so squirrely I'm not sure what plugins in this room are on what breakers.

 

[Jim greengo]

Start with loose connections in panel,and new outlets if old ones are loose.

 

[sberry]

That seems a bit much, I might be looking at connections too. These are the things I like to rewire and the best scene for a heater is a 12 wire, from breaker to outlet.
When I hear 14 wire I start thinking backstab.

 

[wyliesdiesels]

Not much as there's no voltage drop until I turn the heater is on at least low. Maybe a lamp, maybe a lamp and my computer (If it is it uses very little). The wiring is so squirrely I'm not sure what plugins in this room are on what breakers.

how long is the wire run?

 

[kaffine]

What is the voltage at the panel during the same time? Making sure the voltage drop is between the breaker and the outlet not the transformer and panel.

 

[pattenp]

What circuit size does the specs on the heater call for? It may need a 20A circuit.

 

[sberry]

I am not a fan of hooking heating on old general circuits. I use those heaters on occasion and I pretty much run a new wire for them on 20A. Eliminate as many old connections as I can, most of the time all of them. If this is your own home,,, which is likely since its 15A I would be tempted to run a new wire if its humanly possible.
Doubly true if you describe the wiring as "squirrelly".