I have a customer who has a service receptacle under the main panel outside... It is on a single pole 20 amp breaker all by itself and is reading 220 volts ... The neutral is connected to the neutral bar ,, hot to breaker and ground to the separate grounding bar ... When they put a meter on the neutral bar and the ground bar ,, its reading 117 v ..
Service receptacle getting 220
- Thread starter rydan
- Start date
- Status
Daniel malack
Senior Member
- Location
- Amissville, Virginia USA
What is the voltage phase to phase? And each phase to ground/ neutral?
Sent from my SM-T350 using Tapatalk
Sent from my SM-T350 using Tapatalk
JFletcher
Senior Member
- Location
- Williamsburg, VA
What NEMA configuration is that receptacle?
220V is too high for a high leg, and 120V neutral to ground in the panel doesnt jive either... you sure they traced the wires correctly/have correct readings?
eta: is the panel a main or a sub? 1ph or 3? and did they take any other readings on the receptacle,
Last edited:
Daniel malack
Senior Member
- Location
- Amissville, Virginia USA
Also if this is a main panel not a subpanel, the ground and neutral should be connected.
Sent from my SM-T350 using Tapatalk
kwired
Electron manager
- Location
- NE Nebraska
Sounds like either bad neutral - which would give you odd voltages on other circuits and it would vary depending on load conditions, or maybe if someone had been working on it they may have crossed neutral and an ungrounded lead.
Measurements between all lines, with load as well as without load, and reporting that to us would help a lot in narrowing down the issue, and description of what is supplying this panel.
If it is something that had been working but recently developed this issue - I'd look into an open neutral first.
mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
Or the neutral opened and resulted in one leg going up and the other going way down.
JFletcher
Senior Member
- Location
- Williamsburg, VA
They/you placed a service call that was addressed and corrected in little over an hour, on a Sunday? :huh:
Although I can visualize an inadvertent connection between the neutral and 1 phase, I dont see how that would create 120V on the neutral and the readings obtained, unless the neutral was lost at the pole.
In any case, glad the problem was found.
Me neither- if the neutral was still intact up at the pole, there would a short with either opened co's or burning wires if a skinned hot and neutral on the drop touched each other.
I was surprised as well .. Lake Worth Utilities are generally slow... they have a hot line to call .. She sent me a picture of the branch the worker had to chop down .. From the looks of it ,, it melted thru the lines causing the neutral to energize . As well ,, its a simple 2 phase outdoor Nema 3 panel (old home) No inside panel.. Siemens . She stated after they replaced the lines she had everything up and running... What got me , was she had a window shaker unit, 220v that was working when nothing else in the house worked ,,, I'm figuring cause it wasnt connected to the neut.
mbrooke
Batteries Included
- Location
- United States
- Occupation
- Technician
Also broke the neutral to in the process. If the neutral coming back to the utility remained intact, you would have had an interesting fire works show. Glad you got this resolved.
JFletcher
Senior Member
- Location
- Williamsburg, VA
You figure correctly. Pure 240V loads like water heaters and HVAC units have no neutral and therefore do not need a service neutral to function. Matter of fact, all loads, 120 or 120/240V, will work to some degree w/o the service neutral. With no neutral, 120V loads on opposite legs work in series instead of parallel. It's only when the load on each leg is highly imbalanced that losing a service neutral will fry equipment.
and it's center tapped single phase or split phase - 2 phase is an old, obsolete system.
kwired
Electron manager
- Location
- NE Nebraska
Two phase was probably never utility company distributed anywhere in Florida.You figure correctly. Pure 240V loads like water heaters and HVAC units have no neutral and therefore do not need a service neutral to function. Matter of fact, all loads, 120 or 120/240V, will work to some degree w/o the service neutral. With no neutral, 120V loads on opposite legs work in series instead of parallel. It's only when the load on each leg is highly imbalanced that losing a service neutral will fry equipment.
and it's center tapped single phase or split phase - 2 phase is an old, obsolete system.
- Status