Hello, I just installed a 10 KW 240 volt heater in my garage. I used 4 GA wire and a 60 Amp breaker. Everything seems to work fine. However when I checked the current draw with my clamp-on ammeter, I see 41.7 amps on each hot wire and 26 amps on my neutral/ground wire. How can that be? I expected to see no current in the ground/neutral wire? Can anyone explain this to me?
Thanks,
Tuffguy23

Something's is wired a little weird, the Neutral should read the difference of both hots, being the same, it should be zero?
Do you really need a Neutral? You are going to have to separate the ground and neutral, be careful, and see which is drawing current, neutral or ground. An internal short, or missconnected?

Verify you have 240 volts between both hots.

There should be no neutral on an electric heater of this size, unless of course it has a fan or other load that is 120v. Even then it is highly doubtful that anything 120v would draw 26A.

Where did you terminate the neutral?
Does the heater have a fan?

Do you have the make and model number of the heater?

Any chance you have a 3 phase service?

OK, UPDATE: Thanks for the answers. This is a single phase heater and service. My first post was a measurement inside my house service panel. Today I measured the current again, but from inside the heater itself. This time I get 41.7 Amps on both hots, and zero on the ground/neutral as I expect. I measure again at the main service panel and get 41.7 on both hots and again 26 Amps in the ground ( tied to the neutral bus bar ). Seems like there is some weird induced current into the ground wire from the hot wire. I did run 2 conduits to the heater. One contains a hot wire, and the other contains the ground and the other hot wire. I can't think of any other explanation. The heater does work fine, although the conduit with the 2 wires in it gets slightly warm after a short time and the other conduit ( with one hot wire only) stays cold. Go figure?
Thanks.

The 2 hots and ground need to be in 1 conduit, separate the hot and ground. Do not put the hot to ground.

Tuffguy, WHY would you run two conduits and separate the conductors??

PLEASE correct this by running all three conductors in the same conduit. I bet this is where your mystery current is coming from.

#4 is overkill, 6's would work. However, overkill on a wire is not a bad thing, reduces voltage drop, and more expensive.
Is the #4's why it won't fit in 3/4" Greenfield?

Thank you for these answers. Yes, 4 gauge is overkill. I was planning to add a second heater if needed so I was planning ahead. I used 2 conduits to reduce any need for derating due to heat buildup. But I will re-pull the wires into one pipe and report the findings. Thanks again!

1" would work, I don't think anything is induced, I feel something is contacting ground accidentally, or hooked to a hot.
To confirm, this other load is through the Neutral or ground?
What happens when this is not connected,
And like Above, What exactly do you have?

OK, Final Update: Thank you guys, you are a wealth of information. My heater is a Fostoria model FES-1024-1ca. 240v 10kw 1ph. I repulled the wires into a single conduit as you suggested, and the 'phantom' 26 amps in my ground wire is gone. It seems I put too much thought into separating the wires into 2 conduits to improve theoretical operation. This only maybe created a weired induced current. Anyway, thanks again. You guys are great!

Good example why all circuit conductors must be run together, never separated.
I am going to guess the conduit was plastic and not metal. Metal conduit would get warm or even hot with a conductor separated from it's partners.

Real glad you noticed the induced current and asked the question.