Hi, we have a system that has a C ph. grounded, it's a 480v delta with corner ground. Why is this done and what color would you phase it, since there is no stinger leg? This feeds 2 transformers one with ph. A&B with both legs being protected by a breaker, and the other with ph. A&C and only ph. A being fused. If both are hot legs, why is ph. C not protected? Thank You Dennis Price
480v delta with corner ground
- Thread starter dhp1282
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charlie
Senior Member
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- Indianapolis
Re: 480v delta with corner ground
Treat the grounded phase about the same as you would a neutral. You may switch it if you switch it with the other phase conductors. If it goes through a fused disconnect, you can purchase a "slug" for the grounded phase. You need to take a grounding class to learn all the "whys" to the rules in Article 250 on this subject.
Treat the grounded phase about the same as you would a neutral. You may switch it if you switch it with the other phase conductors. If it goes through a fused disconnect, you can purchase a "slug" for the grounded phase. You need to take a grounding class to learn all the "whys" to the rules in Article 250 on this subject.
Re: 480v delta with corner ground
Why is this done and what color would you phase it, since there is no stinger leg?
Because it is a grounded system. Same color as any grounded circuit conductor. White comes to mind.
If both are hot legs, why is ph. C not protected?
Because you cannot fuse a grounded circuit conductor.
[ March 11, 2004, 10:36 AM: Message edited by: dereckbc ]
Why is this done and what color would you phase it, since there is no stinger leg?
Because it is a grounded system. Same color as any grounded circuit conductor. White comes to mind.
If both are hot legs, why is ph. C not protected?
Because you cannot fuse a grounded circuit conductor.
[ March 11, 2004, 10:36 AM: Message edited by: dereckbc ]
Re: 480v delta with corner ground
In SE Wis we have something similar--240 3ph, 3w, grounded 'B'.
If you saw the service it would look just lke a single phase 120/240. In fact at one point in time some contractors were actually installing SqD 100Amp Main breaker QO panels for 240 grounded B. This is, of course, not allowed. The main is not rated for 240 to ground. You also need to use "H" breakers as these are rated 240v to ground.
In SE Wis we have something similar--240 3ph, 3w, grounded 'B'.
If you saw the service it would look just lke a single phase 120/240. In fact at one point in time some contractors were actually installing SqD 100Amp Main breaker QO panels for 240 grounded B. This is, of course, not allowed. The main is not rated for 240 to ground. You also need to use "H" breakers as these are rated 240v to ground.
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