GFI receptacles for outdoor locations
- Thread starter Pitt123
- Start date
- Status
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
The GFCI can share a neutral on the line side but not the load side.
Look at art.210.8(B) for GFCI requirements for non dwelling
Look at art.210.8(B) for GFCI requirements for non dwelling
Can you clarify what you are calling the load and line side of the receptacle and why the neutral cannot be shared on the load side?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
A gfci recep. has a line and load terminals. A gfci breakers line side is the buss bar and the load terminals go to the circuit.
In the case of a gfci breaker you could use a DP gfci breaker and the load side would work with a MWBC.
In the case of a GFCI recep. tyou could not connect the load side of a GFCI to the second circuit of a MWBC. You would have to make that connection on the line side of the device.
In the case of a gfci breaker you could use a DP gfci breaker and the load side would work with a MWBC.
In the case of a GFCI recep. tyou could not connect the load side of a GFCI to the second circuit of a MWBC. You would have to make that connection on the line side of the device.
So if I have other non GFCI receptcales on the MWBC I can connect these receptacles on the load side terminals of the initial GFCI receptacle and these receptacles will then be considered GFCI protected?
However if the other receptacles are GFCI recepts then they must be connected to the line side of the first GFCI recpt? They could use the same neutral but would just need to be connected on the line side of the recpt?
Can you explain the reason for this?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I am confused by your setup. Lets assume we have gfci receptacles and not GFCI breakers. If you run a MWBC you are running 2 circuits that share a neutral. If cir. #1 feeds a GFCI breaker then all the regular recep. installed on the load side of that gfci are protected.
If you want to use Cir. #2 you must connect the neutral to the line side of the and not thru the GFCI of cir. #1. You can the add a gfci downstream of that point or just have a plain non gfci circuit.
You would not need gfci recep. on the load side of a gfci. You would install
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Absolutely.
Yes. A shared neutral must be split ahead of each 2-wire-supplied GFCI receptacle, effectively pigtailed as you would with any shared neutral.
A GFCI device trips when the current in one conductor is not returned by another circuit conductor(s). All circuit conductors must pass through the current-sensing ring in the GFCI.
A shared neutral has no way of knowing how much of its current is being supplied by its line conductor, and how much of it by another, so all current will appear as an imbalance.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Gesundheit!
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
I see what you are saying here. I was confusing terminology with a 2wire consisting of a hot and neutral and a MWBC consisting of multiple hots and a shared neutral.
If I just have one circuit with a hot and neutral then I can connect other receptacles either GFI or non-GFI onto the load side of the first GFI receptacle and connect the other receptacles in parallel with this hot and neutral.
If however there are other receptacles being fed from a second hot circuit then the shared neutral needs to be connected onto the line side of the GFI receptacle. As long as it is connected on the line side then I assume you can use the same neutral to feed other GFI's downstream of the first using a second circuit for the other receptacles.
How about for a GFI breaker? How does it see the neutral current coming back? Can you used a shared neutral with circuits protected from GFI breakers?
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
Seems like you got the first part correct. I thought there was some confusion going on because of the wording of the question.
It would be no different than a GFCI receptacle. You cannot share the neutral of a GFCI circuit unless both circuits are GFCI protected and you use a DP GFCI breaker. If you share a neutral on a MWBC with a single gfci breaker and a regular breaker then you will have constant tripping of the device because this device is looking for currents in on the hot to be the same as the current out on the neutral. This would not be the case with a shared neutral.
- Location
- Chapel Hill, NC
- Occupation
- Retired Electrical Contractor
On a 2 wire circuit with a load of, say, 10 amps, the GFCI reads 10 amps in on the ungrounded conductor and 10 amps out on the grounded (neutral) conductor.
On a MWBC the neutral will read the difference between the 2 different phases. Thus cir #1 has 10 amps and say cir#2 has 5 amps then the neutral will read 10-5=5 amps. This will cause the gfci to trip-- I believe the GFCI will trip on a difference of about 5ma.
On a MWBC the neutral will read the difference between the 2 different phases. Thus cir #1 has 10 amps and say cir#2 has 5 amps then the neutral will read 10-5=5 amps. This will cause the gfci to trip-- I believe the GFCI will trip on a difference of about 5ma.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Yes. What matters is that only a two-wire (no shared conductors) circuit be connected to the load terminals of a GFCI receptacle.
Only with a 2-pole GFCI breaker, which passes all of the circuit conductors through the current-sensing ring.
There are no 3-pole GFCI breakers that I'm aware of, so beware.
- Status