GFI breakers

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myrshub

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central CA
We have a panel @ work that is strictly going to be used to power up pumps and lighting for some aquariums in a science classroom.

The wire was pulled to the recepts before the panel had arrived. We pulled some MWBC's with a single neutral. and filled the conduits.

Now that we have the panel my foreman noticed all the breakers are GFI type. He tried to make up the panel and when he got to the neutrals he noticed that with the MWBC's he only has one neutral for 3 circuits and has to land the neutrals on the breakers.

He wants to pigtail the neutral for all 3 circuits in the panel :roll:. Besides being "hackish" what problems would this cause? Will the breakers operate properly?
 
I agree the breakers will not work properly so install three GFCI recep. of dead front gfci's at the pumps. The line side neutral can be pigtailed to each recep. so this will work fine- use standard 3 pole breaker or 3 sp with breaker ties.
 
connecting the neutrals between the GCFI breakers will cause the breakers to trip, as the breaker will sense this as a leakage to ground, MWBC are a big problem with GFCI breakers, you can use MWBC before a GFCI device but not after one.

As was posted, if on the 2005 NEC in your area, replaceing the breakers with single pole units regular breakers and installing GFCI receptacles at the point of use, will be the most cost effective way out of this, but if they insist on GFCI breakers, then repulling the circuits will have to be done.

If your area is on the 2008 then 3-pole breakers will have to replace the single pole units.
 
hurk27 said:
If your area is on the 2008 then 3-pole breakers will have to replace the single pole units.
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Not necessarily... If 120/208 MWBC with GFI devices - the 3 pole CB's will have to stay... The 08 code does not dis-allow MWBC's but required simultaneous disconnect... (They do make 2P GFI's... ) so if using single pole breakers - nothing says they can't be handle tied - not that there would be a reason to do so.... ;)
 
e57 said:
Not necessarily... If 120/208 MWBC with GFI devices - the 3 pole CB's will have to stay... The 08 code does not dis-allow MWBC's but required simultaneous disconnect... (They do make 2P GFI's... ) so if using single pole breakers - nothing says they can't be handle tied - not that there would be a reason to do so.... ;)
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H'mmm Ok but that was what I was saying?:confused:

the OP said he has a panel loaded with single pole GFCI's, but had wired using MWBC's?
 
Another solution, depending on the load on each circuit, would be to triple up all the hots to a common pigtail and put that on one breaker along with the neutral. Otherwise, sell the GFCI breakers or swap them for 3 poles -- you'll probably come out ahead money wise.
 
I think your best way out is to pull 2 more noodles. (if feasible) You already have the breakers. One quick thought: When all 3 GFCI circuits share the same neutral, they will probably stay "on," but as soon as there is a load, one will trip. I once went behind someone who did that in a kitchen with a MWBC and he later claimed that they were working when he left the job!
 
hurk27 said:
H'mmm Ok but that was what I was saying?:confused:

the OP said he has a panel loaded with single pole GFCI's, but had wired using MWBC's?
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Hurk, the problem is you said they must be 3 pole breakers and e57 and I both stated that single poles with handle ties could be used. Essentially it is the same but the handle ties with single poles are must cheaper then a 3P breaker.
 
Mulrooney said:
Off the subject a bit, is gfi protection required for aquariums?
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No, not required. But apparently someone thought it would be a good idea to GFCI protect these outlets - maybe the engineer??

School kids, electricity, and water - not a good mix :)

I just planned out teh receptacles for a science room, and I just decided to make every receptacle GFCI. Its cheap protection. You never know what they are going to plug into these, what condition it will be in, and how the kids will be handling this equipment.
 
We were able to squeeze another neutral into one of the conduits but not the other. Were going to replace 3 of the gfi breakers with standard breakers and use gfi recept's for them.

Thanks for the info passed along.
 
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