Was trouble shooting some equipment the other day and ran into a Square D Ground fault detector. Was a small unit with a separate CT sensing unit. This is a 480/277 400 amp service. My question as never seeing one of these, is how would you?go about finding the wire that's going to ground. This unit was tripping intermittently.
Ground Detectors
- Thread starter ken987
- Start date
- Status
petersonra
Senior Member
- Location
- Northern illinois
- Occupation
- engineer
Re: Ground Detectors
I'm not sure there is any indication of which leg is causing the trip.
Maybe a late night session with the megger when you can schedule a shutdown.
I'm not sure there is any indication of which leg is causing the trip.
Maybe a late night session with the megger when you can schedule a shutdown.
charlie tuna
Senior Member
- Location
- Florida
Re: Ground Detectors
since the problem is "intermittent" you might have a hard time finding it. i am assuming the voltage is 480/277? first thing i would consider is what has changed that may have caused some type of "ground" to occur. water is a prime suspect, or even dampness? maybe a new piece of equipment? maybe a change in the electrical system like a tenant build out? then i would meggar those suspected areas after hours when the power can be shutdown. i would set the meggar on the highest voltage reading to ground. another suspect might be the ground fault module itself? they do go bad! check the inside of the switchgear could have a new family of mice moved in from the cold weather???
since the problem is "intermittent" you might have a hard time finding it. i am assuming the voltage is 480/277? first thing i would consider is what has changed that may have caused some type of "ground" to occur. water is a prime suspect, or even dampness? maybe a new piece of equipment? maybe a change in the electrical system like a tenant build out? then i would meggar those suspected areas after hours when the power can be shutdown. i would set the meggar on the highest voltage reading to ground. another suspect might be the ground fault module itself? they do go bad! check the inside of the switchgear could have a new family of mice moved in from the cold weather???
- Status