I am doing a job at a church that is fed with a 240 Delta 3 phase 4 wire service. I am installing power for 9 -240 volt single phase A/C units. There is an existing 175 amp feeder that is 3 phase 3 wire that I want to use. Now I know the code requires a neutral at all service equipment on a grounded system but is it necessary for me to bring a neutral to a feeder panel if I don't need any neutral connections? Can I use a 3 phase 4 wire panel with a ground bar only and remove the neutral?
3 phase 3 wire panel on a 3 phase 4 wire Delta system
- Thread starter Foxm
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kwired
Electron manager
- Location
- NE Nebraska
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- EC
Is code compliant, just beware that if you have 120/240 system, it may be tempting for someone to try to connect a 120 volt circuit someday.
If you do install a neutral for limited 120 volt loads - it only needs to be same size as minimum required EGC, if it is a 200 amp feeder you could use a 6 AWG copper if the neutral load isn't more then the ampacity of 6 AWG.
If you do install a neutral for limited 120 volt loads - it only needs to be same size as minimum required EGC, if it is a 200 amp feeder you could use a 6 AWG copper if the neutral load isn't more then the ampacity of 6 AWG.
texie
Senior Member
- Location
- Fort Collins, Colorado
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- Electrician, Contractor, Inspector
As others have indicated, that is compliant. I'm guessing you intend to use all 3 phases line to line and that will require straight 240 rated breakers but that is not a big deal. While not required, I generally like to mark panels like this that there is no neutral present.
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- Placerville, CA, USA
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- Retired PV System Designer
Whether or not a neutral is used has no effect on the voltage to ground and therefore the suitability of slash rated breakers.
If it were an ungrounded, high leg, or corner grounded delta, then full rated breakers would be required.
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If it were an ungrounded, high leg, or corner grounded delta, then full rated breakers would be required.
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chris kennedy
Senior Member
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- Miami Fla.
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- 60 yr old tool twisting electrician
Sounds to me like he's got a 208 bus.
texie
Senior Member
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- Fort Collins, Colorado
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- Electrician, Contractor, Inspector
The OP has a described a 120/240, 3 phase 4 wire delta grounded service. If he intends to use the high leg with 2 pole breakers, fully rated breakers are required regardless if he has a neutral present at his subpanel or not.
kwired
Electron manager
- Location
- NE Nebraska
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- EC
full rated breakers is typically only an issue with the two pole breakers as the three pole breakers are usually 240 volt rated as standard.
Food for thought: if there is no neutral present, the high leg technically doesn't need identified either.
Food for thought: if there is no neutral present, the high leg technically doesn't need identified either.
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