5 volt difference between legs

Generac, Guardian, Honeywell, Siemens, Centurion, Watchdog, Bryant, & Carrier Air Cooled Home Standby generator troubleshooting and repair questions
Post Reply
JP$
New Member
New Member
Posts: 1
Joined: Fri May 22, 2020 2:15 pm

Just installed a 22kw Guardian and when testing power I noticed there is a 5 volt diff between the two legs 245v (125/120). It doesn't sound out of limits, but I ask because during ops checks I lost a sump pump and a furnace blower. Both motors were over 12 years old and ran a LOT so I'm inclined to think that they were just old and the power switching just put them over the edge. I can find no other issue in the gen except the voltage beta. Grid power is a solid ,if not slightly high, 250v (125/125) 60hz and when the gen is running its a consistent 245v (125/120) 60hz, load and no load. Any thoughts on the this topic would be appreciated. Thanks
Chris
Site Admin
Site Admin
Posts: 1859
Joined: Sat Aug 04, 2018 8:46 pm
Location: Clawson, MI
Contact:

It sounds more like a loose neutral connection somewhere. Did you check the voltage at the furnace and sump pump during the test? A sump pump motor is pretty forgiving for voltage variations since it's just a motor and has no controls.
Generac tech for over 12 years. I'm here to help!
"The only source of knowledge is experience" -Albert Einstein
Looking for Generac parts? Gentek Power offers the full line of Generac replacement parts! Shop Gentek Power Generac Parts
A list of my favorite Generator & Electrical Tools! https://www.amazon.com/shop/gentek_power
Birken Vogt
Top Contributor
Top Contributor
Posts: 139
Joined: Sun Nov 11, 2018 12:02 am

Also a single phase motor does not care if legs are unbalanced so long as its 2 terminals stay within spec. 120+125 = 245 which would be fine for that motor. It may be a symptom of another problem or it may just be the way it is.
Post Reply