I am an on-site technician performing routine maintenance and repairs on mechanical and electrical equipment. I’ve found that testing for continuity between ground and line (hot/positive), with the breaker off of course, I regularly read about 100 ohms. I would be more worried if it wasn’t consistent for most all the circuits I try this on, but it is. Is this standard breaker panel set up for commercial facilities? Couldn’t find solid answers on other forum posts here and elsewhere. I apologize if this is being posted in the wrong category.

 

It's a relatively meaningless number. Any device connected shows up as resistance, Motors would show up as resistance and not inductance.

 

Circuit breakers simply open-circuit and disconnect Line. With the breaker off, load's resistance will take Line down to the Neutral potential. You might just be seeing a lamp ballast's resistance.

Instead of resistance, try measure ACV (breaker off) from Line and Neutral to GND. Usually there is some potential between Neutral and GND, and this causes ohmeters to read incorrectly, which you might be seeing. Like reading ohms from Neutral to GND.
I'm not sure why you are taking these readings, they don't give useful information?
P.S. I don't recommend reading ever reading resistance on Line, it's dangerous especially with cheap multimeters.

 

It's a relatively meaningless number. Any device connected shows up as resistance, Motors would show up as resistance and not inductance.

Sorry, I should’ve been more clear. The specific spots I was taking this measurement from lately were between a disconnected line that powers a wire heater and the metal wall of a walk-in freezer. Come to think of it though, there are multiple loads on this circuit so perhaps those are what’s showing up on that’s reading?

 

I’ve found that testing for continuity between ground and line (hot/positive), with the breaker off of course, I regularly read about 100 ohms. I would be more worried if it wasn’t consistent for most all the circuits I try this on, but it is. Is this standard breaker panel set up for commercial facilities?

That's a meaningless measurement. It will depend on what's on that circuit and is switched on.

 

Circuit breakers simply open-circuit and disconnect Line. With the breaker off, load's resistance will take Line down to the Neutral potential. You might just be seeing a lamp ballast's resistance.

Instead of resistance, try measure ACV (breaker off) from Line and Neutral to GND. Usually there is some potential between Neutral and GND, and this causes ohmeters to read incorrectly, which you might be seeing. Like reading ohms from Neutral to GND.
I'm not sure why you are taking these readings, they don't give useful information?
P.S. I don't recommend reading ever reading resistance on Line, it's dangerous especially with cheap multimeters.

Thank you! I typically do so, but best practices always need reminding. “Sorry, I should’ve been more clear. The specific spots I was taking this measurement from lately were between a disconnected line that powers a wire heater and the metal wall of a walk-in freezer. Come to think of it though, there are multiple loads on this circuit so perhaps those are what’s showing up on that’s reading?”
I was taking readings here partly out of curiosity, but also to see if there might’ve been anything anomalous affecting the current running to my heating wire. I already figured there was an issue with the hearing wire itself; just an attempt at thoroughness. I assumed my reading was a panel set up thing only because if that reading was accurate when the breaker was turned on it’d most likely immediately trip or cause a fire or some such issue lol. Reading between ground and neutral here always shows next to no resistance because they’re connected in our breaker panels.

 

That's a meaningless measurement. It will depend on what's on that circuit and is switched on.

That is certainly seeming to be the case. There is are two light fixtures, a heater wire and a thermometer/temp alarm on this circuit. When I take this reading everything is off. It’s more of a fun curiosity thing for me at this point.

 

Quick example. There is step-down control transformer connected. You could be reading the DC resistance of the winding, not the AC impeadance. Since the "current in an inductor cannot change instantaneously", that DC resistance is the cause of the "surge current" when an inductive load is switched on.

 

Come to think of it though, there are multiple loads on this circuit so perhaps those are what’s showing up on that’s reading?

That would be my guess. Mains breaker off. I measure line to neutral at the breaker. I will see whatever load resistances are out there on the branch circuit.

Ron