240 volts across hot to nutral

Status
Not open for further replies.
S

strauby21

Member
Hello,

I have a panel (Its a old panel Starts wirh Z). When one of three separate single pole breakers are turned on the lights get bright and blow bulbs. when you check for voltage I get 240 from hot to nutural and nothing across the other hot to nutral. Im thinking a bad panel. any help would help thanks,

jim
 
strauby21 said:
Hello,

I have a panel (Its a old panel Starts wirh Z). When one of three separate single pole breakers are turned on the lights get bright and blow bulbs. when you check for voltage I get 240 from hot to nutural and nothing across the other hot to nutral. Im thinking a bad panel. any help would help thanks,

jim
Click to expand...


Bad panel???? Did you check the neutrals in this scenario?????
 
strauby21 said:
I have a panel (Its a old panel Starts wirh Z). When one of three separate single pole breakers are turned on the lights get bright and blow bulbs. when you check for voltage I get 240 from hot to nutural and nothing across the other hot to nutral. Im thinking a bad panel. any help would help thanks.
Click to expand...

You need to give (or get) more information.

What other voltage readings do you have?
a-b? b-c? c-a? a-n? b-n? c-n?

Is the panel marked for what voltage is **supposed** to be feeding it?
What is upstream of this panel?
What sort of installation is it? Use?
 
panel.jpg
 
strauby21 said:
Im thinking a bad panel. any help would help thanks,
Click to expand...
If it starts with Z, it probably is a bad panel, but that's not your problem. Fix your open neutral, then replace the panel with one that starts with a C or an S.
 
do you have 120 or 240 when you measure between hots? what about measuring to ground? is it single phase or 3 phase? are you measuring the wild leg of a 120/240v 3 phase system? or do you have a missing neutral either in the meter socket or utility side?
 
strauby21 said:
Hello,

I have a panel (Its a old panel Starts wirh Z). When one of three separate single pole breakers are turned on the lights get bright and blow bulbs. when you check for voltage I get 240 from hot to nutural and nothing across the other hot to nutral. Im thinking a bad panel. any help would help thanks,

jim
Click to expand...


If it's an old panel, it's probably an overhead service. Check the lateral and the service drop for a broken messenger wire (neutral). Pull the meter and check voltage at the meter. If you get the proper voltages, then proceed troubleshooting the panel.
 
This is a single phase residential service. There is a 200 amp disconnect under the meter. At the panel I have 240v from hot -hot. 120v from hot -N until I turn a single pole breaker on the I get 240v hot-n and 0volts from other hot-N
again thanks for all the info

jim
 
Sounds like you might be backfeeding one leg 120V on the neutral when you turn that one circuit on

Which should in theory trip your breaker or main, unless there is no grounding system at the residence

Does the readings change when you turn just a certain circuit on or any breaker?
 
Last edited:
mdshunk said:
If it starts with Z, it probably is a bad panel, but that's not your problem. Fix your open neutral, then replace the panel with one that starts with a C or an S.
Click to expand...


I like your thinking but a c panel should have the brown handles IMHO.
 
Sorry.

My brain needs every bit of info to process troubleshooting. I understand the 240V thing as an open neutral but am losing it on the phase that somehow loses voltage.

Start at the source. Check everything phase to phase on both sides of over current devices.
 
strauby21 said:
This is a single phase residential service. There is a 200 amp disconnect under the meter. At the panel I have 240v from hot -hot. 120v from hot -N until I turn a single pole breaker on the I get 240v hot-n and 0volts from other hot-N
again thanks for all the info

jim
Click to expand...

the fastest way to verify if you have bad netral in the system is turn off all the 240 volts devices off then check the voltage L1-N and L2-N .

at the same time check the EGC as well. [ that can get overlook if not carefull with it ]

Merci, Marc
 
Thanks for your advice I called power company and the problem was at the
pole (Broken neutral) and I am putting in a panel that starts with S.

Thanks

Jim
 
mdshunk said:
If it starts with Z, it probably is a bad panel, but that's not your problem. Fix your open neutral, then replace the panel with one that starts with a C or an S.
Click to expand...

I've got some used challenger's and stab-loks you can buy. Used but minimal scorching.;)
 
Is everything wired in 12 wire? Other than that you have an open neutral you had better call the power company imediately and get it fixed imediately before you burn the house down. Check the batterys in the smokes and sleep with one eye open if you must.
 
Status
Not open for further replies.
Top