Ground fault 4000 amp GE power Break 1, Manual type

F

Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Had a call on a 4000 amp Main breaker. It has tripped 2 times. This past tuesday. and 6 months ago.
Happened at 200 am, They company employees Tried to Reset breaker. But after charge, Would not close, And remained open. And 3 attempts 2 hr later,
It finally reset.
I viewed the screen on the Microversa Trip plus trip unit. And it looks to have a error code displayed, .23 I believe GF code, Which is ground fault. Any input,

They want to remove this breaker. And replaced.

GE TP4040TR Power break 1 type.
4000 amp CT Chip in Micro switch
Microversa Trip plus trip unit
 
I had a similar call from an insurance company headquarters.
The GF setting of the main had never been coordinated with downstream branch breakers. When set to minimum it would trip before a 30A branch breaker. So this was the first thing we 'adjusted' followed by field testing, before replacing the breaker.

The GF was eventually traced to a new set of duct heaters, when enough banks were on the system faulted, when only one or two banks were on things ran fine.
 
Fordean said:
Yes trying to upload
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If the sensor is 4000A, then it is showing a 920A GF (0.23x4000). That is a pretty good amount. I would investigate for GF, and do primary injection testing on the breaker before replacement.
The maximum setting permitted is 1200A, so even if there was a coordination problem, you don't have too far to move it up.
 
ron said:
If the sensor is 4000A, then it is showing a 920A GF (0.23x4000). That is a pretty good amount. I would investigate for GF, and do primary injection testing on the breaker before replacement.
The maximum setting permitted is 1200A, so even if there was a coordination problem, you don't have too far to move it up.
Click to expand...
Don't forget the time delay element. This often has a bigger impact than the pick up value.

Consider adding a second level of GF to feeder breakers, this will reduce the area affected by a trip as well as help to locate an intermittent fault. Not that hard to do with today's electronic breakers, so I don't know why it is not more common, definitely cheaper than an unplanned outage.
 
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Attached is a copy of the job work order from GE 30 years ago. The 2000 amp and 4000 amp breakers tied with Kirk key I believe. The 4000 amp is online. and the 2000amp is off. The 4000 amp would not reset. Can we switch to the 2000 in Emergency. The Generator is 1 meg i believe.
 

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Fordean said:
Attached is a copy of the job work order from GE 30 years ago. The 2000 amp and 4000 amp breakers tied with Kirk key I believe. The 4000 amp is online. and the 2000amp is off. The 4000 amp would not reset. Can we switch to the 2000 in Emergency. The Generator is 1 meg i believe.
Click to expand...
You'll need a oneline to show what the 2000A and 4000A are fed from to figure it out. It would seem odd to have a 4000A and 2000A breaker from the same size utility service.
 
ron said:
You'll need a oneline to show what the 2000A and 4000A are fed from to figure it out. It would seem odd to have a 4000A and 2000A breaker from the same size utility service.
Click to expand...
4000 is utility 2000 is a em gen back up

If Gen and utility both fail
 
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