Generac 10000e and flourescent lighitng causing Nuisance tripping

[JFletcher]

Wouldnt the building grounds be bonded to the POCO neutral? and if there is power on the building, wouldnt a few mA or more from the building try to find all paths to source, including thru its grounds, its steel, thru your MC cable or grounded lights into your bond at the generator, which would trip a GFCI?

 

[NjWireMan]

Most of my test are with the lighting load only. All the lights are on 1 breaker, 1 phase. 10 lights. Standard 2ft by 4ft troffer flourescent lights that work with either 120 or 277v. Pre wired with bulbs installed out of box. Installed hundreds of them.
This particular generator was picked for its true power.


At this i am just going to plug the leads to the light right into the generator and see if it trips. If it trips I will have to disconnect the bond in the generator. If that doesnt work than I will have to disconnect the gfci. I guess????

 

[GoldDigger]

Wouldnt the building grounds be bonded to the POCO neutral? and if there is power on the building, wouldnt a few mA or more from the building try to find all paths to source, including thru its grounds, its steel, thru your MC cable or grounded lights into your bond at the generator, which would trip a GFCI?

The typical (that is actually all) GFCIs do not pay any attention to current on the EGC. In fact they do not even require an EGC connection.
As long as the current going out the hot balances exactly with the current coming back in the neutral there will not be a trip.
Note that excess current from another circuit coming back over this neutral would trip the GFCI. But current in the EGC, no.

 

[JFletcher]

The typical (that is actually all) GFCIs do not pay any attention to current on the EGC. In fact they do not even require an EGC connection.
As long as the current going out the hot balances exactly with the current coming back in the neutral there will not be a trip.
Note that excess current from another circuit coming back over this neutral would trip the GFCI. But current in the EGC, no.

All true; GFCI wont care about the grounding wire, whether its there or not, carrying current or not. However, the bond on the generator provides a path from EGC to neutral. Perhaps I didnt phrase my question the way I intended: with the bonding jumper on the generator, would current on the building's grounds (which are tied to the generator neutral) cause the generator GFCI to trip? The shop vac the OP plugged in is isolated and did not trip the breaker, which is expected. If the same shop vac was plugged into an outlet fed from the subpanel, wouldnt it trip its breaker?

 

[GoldDigger]

All true; GFCI wont care about the grounding wire, whether its there or not, carrying current or not. However, the bond on the generator provides a path from EGC to neutral. Perhaps I didnt phrase my question the way I intended: with the bonding jumper on the generator, would current on the building's grounds (which are tied to the generator neutral) cause the generator GFCI to trip? The shop vac the OP plugged in is isolated and did not trip the breaker, which is expected. If the same shop vac was plugged into an outlet fed from the subpanel, wouldnt it trip its breaker?

With the bonding jumper on the generator AND no connection between the generator-driven neutrals and the building neutrals AND no other ground/neutral bond downstream of the generator, any current traveling on the generator EGC will not have a parallel path to travel over the generator neutral, so no trip.

If the shop vac is plugged into a generator driven circuit and does not have excessive leakage current it will not cause a trip whether it has an EGC associated with it or not.
If the shop vac has a three wire connection and enough leakage to trip the possibly over sensitive GFCI, then it could trip the generator breaker.
If it has leakage to building ground or directly to earth, it will trip the generator GFCI even without an EGC in its cord.

the building's grounds (which are tied to the generator neutral)

The only tie between the generator neutral and the building neutral will come from the fact that the building neutral is tied to the building ground which is in turn tied to the generator ground and also therefore to generator neutral. But if the only two bonds are at the generator and at the service panel you can try all you want to find a path for building neutral current to travel on the generator neutral or generator neutral current to travel on the building neutral and it is just not there.

 

[Sahib]

The neutral of the generator is bonded to its frame. If you could measure the leakage ground current through that portion of the neutral wire with a sensitive clamp meter after temporarily bypassing the GFCI, you may check
(1)Whether the GFCI is okay
(2)Individual ground leakage current contribution from light fixtures.

 

[NjWireMan]

I havent been back to the generator yet but I talked to a service technician and he seems to think that my generators are set to 50 hertz and not 60 hertz. Something about a slower engine speed and draining to much power and the system is tripping the generator to protect it.

I will test the hertz when I see them.

I still think for some reason there is stray current coming from the building back to the generator through the ground and ground/bond that is in the generator.

What is unfortunate about this situation is this should be just a plug and play scenario.

 

[qcroanoke]

I havent been back to the generator yet but I talked to a service technician and he seems to think that my generators are set to 50 hertz and not 60 hertz. Something about a slower engine speed and draining to much power and the system is tripping the generator to protect it.

I will test the hertz when I see them.

I would be surprised if the engine RPM's are adjustable. I think 3600 rpms is 60 hz. Not sure what rpm is 50 hz.
Engine speed may affect voltage too.

 

[GoldDigger]

I would be surprised if the engine RPM's are adjustable. I think 3600 rpms is 60 hz. Not sure what rpm is 50 hz.
Engine speed may affect voltage too.

50 Hz = 50 cycles per second = 3000 cycles per minute = 3000 revolutions per minute for a two pole generator, 1500 RPM for a four pole generator.

Commercial and full load standby equipment is often four pole to allow a lower engine RPM without gearing for longer engine life.

The change in speed would require at least a 20% offset range available in the voltage regulator circuitry of the generator.

 

[NjWireMan]

I went there this afternoon to do some trial and error on the Generators. I disconnected the bond at the generator and I had the same problem. Whether I used the ground back to the generator or I used the ground to steel the GFCI still tripped.

I could not perform the Hertz test because my multimeter does not have that function. I will get back to that tomorrow morning with a different meter.:thumbsdown:


Since I disconnected the Bond in the Generator should I now bond the neutral to the ground in the Breaker Panel???????

 

[tsparks1]

Can you change the personnel gfci to an equipment gfci. This will give you 30mA of unbalanced current verses 6mA for personnel protection.


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[tsparks1]

Can you change the personnel gfci out for an equipment gfci? This will give you 30mA of unbalance verses 6mA.


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[NjWireMan]

Unfortunately No. Without being a certified generac repair man I technically cannot make any changes.
I will test the hertz today and if that checks out okay I will disconnect the GFCI feature and make it like any other poertable generator. Hopefully that is tyat goes smoothly??

 

[NjWireMan]

Hertz checked out okay with the meter I have.

I have a question. If I disconnect the bond in the generator should I make the bond in my panel??? Remember this panel has no connection to utility. Stand alone panel fed from generator..