There are six 800 amp 480V disconnects used as the main service. I am planning on removing one of the 800 amp 480V service and replacing it with a 1600 amp service in order to meet the six throw rule.Is the neutral required on a three phase service if there would only be three phase motors connected?(No Load on the neutral)
Wye System -- Neutral required or not?
- Thread starter JCT1
- Start date
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Tom.Margillo
Member
Re: Wye System -- Neutral required or not?
Nope.
Nope.
- Location
- Bremerton, Washington
- Occupation
- Master Electrician
Re: Wye System -- Neutral required or not?
On the load side, no.
On the line side yes. Thinks of the grounded conductor as a white wire with an imaginary green stripe. You are not using the white wire (neutral), but rather the green wire, IE its what serves to clear a fault. Your code reference is secion 250.24(C)
On the load side, no.
On the line side yes. Thinks of the grounded conductor as a white wire with an imaginary green stripe. You are not using the white wire (neutral), but rather the green wire, IE its what serves to clear a fault. Your code reference is secion 250.24(C)
Re: Wye System -- Neutral required or not?
Are you sure?
Since this is a service panel wouldn't 200.2 apply that requires a grounded conductor. It is my understanding that the grounded conductor serves as our ground fault return path that is required by 250.5 and reinforced by 250.20. Specifically, 250.24(C) requires that the grounded conductor be brought to "each service disconnecting means". The grounded conductor would be sized using table 250.66 as instructed in 250.24(C)(1).
[ December 21, 2005, 02:44 PM: Message edited by: haskindm ]
Are you sure?
Since this is a service panel wouldn't 200.2 apply that requires a grounded conductor. It is my understanding that the grounded conductor serves as our ground fault return path that is required by 250.5 and reinforced by 250.20. Specifically, 250.24(C) requires that the grounded conductor be brought to "each service disconnecting means". The grounded conductor would be sized using table 250.66 as instructed in 250.24(C)(1).
[ December 21, 2005, 02:44 PM: Message edited by: haskindm ]
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
Re: Wye System -- Neutral required or not?
Haskin, you misunderstood the previous post; it agrees with you. He just worded it strangely.
Haskin, you misunderstood the previous post; it agrees with you. He just worded it strangely.
hurk27
Senior Member
- Location
- Portage, Indiana NEC: 2008
Re: Wye System -- Neutral required or not?
haskin
The service stops at the service disconnect (230.1), if the disconnect is a separate enclosure then the neutral can stop there, but this is where the equipment grounding starts, so a EGC would have to be brought to the remote panel.
haskin
The service stops at the service disconnect (230.1), if the disconnect is a separate enclosure then the neutral can stop there, but this is where the equipment grounding starts, so a EGC would have to be brought to the remote panel.
- Location
- New Jersey
- Occupation
- Journeyman Electrician (retired)
Re: Wye System -- Neutral required or not?
Sounds like he was responding to the post that said "Nope".
allenwayne
Senior Member
Re: Wye System -- Neutral required or not?
Larry you`re losing ground for post police
Larry you`re losing ground for post police
pierre
Senior Member
- Location
- Westchester County, New York
Re: Wye System -- Neutral required or not?
Yes a grounded (neutral conductor is required for the service that is brought to the building - up to the service disconnect.
I did not see anyone mention 230.95. (wye connected services).The OP mentions no load on the neutral, not that there would be no neutral.
This is probably why they installed 6-800 service discos to start with.
[ December 22, 2005, 06:41 AM: Message edited by: pierre ]
Yes a grounded (neutral conductor is required for the service that is brought to the building - up to the service disconnect.
I did not see anyone mention 230.95. (wye connected services).The OP mentions no load on the neutral, not that there would be no neutral.
This is probably why they installed 6-800 service discos to start with.
[ December 22, 2005, 06:41 AM: Message edited by: pierre ]
charlie
Senior Member
- Location
- Indianapolis
Re: Wye System -- Neutral required or not?
Actually, if you look at the requirements in 250.20(B)(1) & (2), you are not required to bring in the neutral unless the serving transformer has the neutral point grounded and the neutral conductor is taken as a circuit conductor.
Actually, if you look at the requirements in 250.20(B)(1) & (2), you are not required to bring in the neutral unless the serving transformer has the neutral point grounded and the neutral conductor is taken as a circuit conductor.
charlie
Senior Member
- Location
- Indianapolis
Re: Wye System -- Neutral required or not?
Thanks Steve.
Thanks Steve.
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