gfi tripping for boat lift new construction

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Dennis Alwon

Dennis Alwon

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fred trueblood said:
2 pole gfi breaker tripping when ground from 10/2 uf is connected ground from either motor using a Gem controller
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What is the egc connected to? If it is connected to the ground bar and the white wire from the dp is connected to a neutral bar then you have current leakage to ground either in the wiring or the equipment
 
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fred trueblood said:
both gfi white tail and grounded conductor connected at same grounding bar
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For a GFCI breaker the neutral for that branch must be connected directly (and only) to the pigtail. That is the only way to force only that branch's neutral current to go through the differential CT inside the breaker.
 
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fred trueblood

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unit has been installed 3 weeks earlier it was just a nuseance trip ocassionaly, tripping bu now i cannot make a connection to the ground from the motors if the ground is omitted gfi works coarse this is a no no
 
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fred trueblood said:
unit has been installed 3 weeks earlier it was just a nuseance trip ocassionaly, tripping bu now i cannot make a connection to the ground from the motors if the ground is omitted gfi works coarse this is a no no
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If you wire the neutral pigtail from the breaker properly and you still cannot connect the EGC at the motor without a trip, then either the wiring is wrong (parallel neutral paths) or the motor has gone bad and is leaking current!

Be very careful as this is a critical safety issue.
 
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fred trueblood said:
have replaced gfi with new not that are you or anyone familiar with Gem
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Tell us one more time about how you connected the neutral pigtail on the breaker? And is it a two pole 240 breaker for a 240V lift motor?

If you do anything other than connect the circuit neutral to the breaker neutral terminal and then connect the breaker pigtail to the neutral bar, you will not get the GFCI to work correctly.
 
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fred trueblood said:
Gem ties both motors together with acontactor and has a loe voltage tran with a circuit board gives you the ability to funtion remotely
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Make sure that the common wire in the low voltage control circuit does not form a parallel path to the power circuit neutral.
That is, make sure that you do not ground the remote control circuit's neutral anywhere along its route.
 
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fred trueblood said:
pigtail is connected to grounding bar grounding conductor fron 10 2 is connected to middle lug of gfi why did it work some before but not at all now
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Because a leakage path has developed during the time the lift and motor have been in place and used?

1. Disconnect the branch neutral (after opening the supply of course). You should not see any continuity between that neutral wire and earth/ground/EGC. If you do, the wiring is messed up.
2. Consider meggering the lift motor(s), being careful not to blow up the controls. :(
 
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fred trueblood said:
are you talking about the grounded conductor it is connected to the motors whitch are grounded to the metal frame of the lift do not have a nuteral
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If there is no neutral wire to the motors, then the circuit neutral is just there to power the control board(s)?

When I say neutral, I mean the white wire which is connected (eventually) to the service neutral from POCO.
That is also referred to as the grounded conductor.
The other conductor involved is the Equipment Grounding Conductor (EGC) which is the usually green wire used to bond the lift frame, motor frame, etc. to the main bonding point back at the service and to the local ground electrodes. Also called the grounding conductor.
For all GFCIs to work correctly, the green wire(s) should not be connected to the neutral bar at any place except back at the service disconnect.
The role of EGC may also be served by metallic conduit or other raceway, but for a marina environment I like to see a wire EGC for good measure.

But basically what the GFCI trip is telling you is that current is going out one of the hot wires and is not coming back through either the other hot or the neutral. That is the definition of leakage current in this situation.
It might be going from part of the motor winding to the motor frame (a defect!) or it might be going through the control transformer primary and to some grounded metal instead of the wire neutral.
 
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fred trueblood said:
thelow voltage transformer has a nuteral were should it be connected
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To the neutral that goes back to the breaker terminal. It should NOT be grounded anywhere. That means that if one side of the low voltage secondary is also connected to the neutral in the control box you must not let that common LV wire touch grounded metal anywhere along the remote control wiring.

If you disconnect the remote control and can still activate the motor, does that trip the GFCI?
If you just connect everything but do not try to actually run the motor does that trip the GFCI? Is so the problem is not likely to be in the motor itself.
 
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