GFCI breaker required for an Oven that doesn't use a neutral

M

mabrunga

New User
Location
Denver
Occupation
Professional Engineer
I've got the following situation on my hands

I need a new connection to a 50A/3P oven, 208V/3P
- Manufacturer calls for a 15-50P with 3 hots and a neutral
-NEC 210.8(B) says i need a GFCI breaker
- GFCI breakers call for a neutral, but the oven doesn't take one.

Please advise.
 
augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
The breaker needs to connect to the neutral buss in the panel. There is no requirement that the neural be connected on the LOAD side. The GFCI still functions.
 
J

jap

Senior Member
Occupation
Electrician
mabrunga said:
I've got the following situation on my hands

I need a new connection to a 50A/3P oven, 208V/3P
- Manufacturer calls for a 15-50P with 3 hots and a neutral
-NEC 210.8(B) says i need a GFCI breaker
- GFCI breakers call for a neutral, but the oven doesn't take one.

Please advise.
Click to expand...

Why would the manufacturer be calling for 3 hots and a neutral if the oven doesen't take one?

Should be 3 hots and an EGC.

JAP>
 
P

PD1972

Member
Location
New York (2017 NEC)
Occupation
engineer
mabrunga said:
I need a new connection to a 50A/3P oven, 208V/3P
- Manufacturer calls for a 15-50P with 3 hots and a neutral
Click to expand...
Which manufacturer? I am assuming the receptacle manufacturer as you note that the oven doesn't take a neutral? Receptacles are labeled with #-Poles, #-Wires where the #-wires indicates how many prongs the plug has and the #-poles indicates how many of those prongs are current carrying. A NEMA 15-50R is noted as a 3-phase 3P,4W receptacle by manufacturers. The 3P, 4W-wire designation does not mean that a 3-phase, 4-wire circuit with a neutral is required. Because the ground is counted as one of the wires (one of the prongs), no neutral is required.

As noted by post #2, GFCI 3-phase circuit breakers do not require a neutral be ran to the load, only that the neutral bus be connected to the circuit breaker. Look up the installation instructions of a 3P GFCI circuit breaker and you can confirm this to be true.

I don't think there is any problem with the situation but maybe I'm missing something.
 
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