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Ground fault 4000 amp GE power Break 1, Manual type

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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
 
J

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
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.
 
ron

ron

Senior Member
Location
New York, 40.7514,-73.9925
Fordean said:
Yes trying to upload
Click to expand...
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.
 
J

jim dungar

Moderator
Staff member
Location
Wisconsin
Occupation
PE (Retired) - Power Systems
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.
 
Last edited:
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F

Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
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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ron

ron

Senior Member
Location
New York, 40.7514,-73.9925
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.
 
F

Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
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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