480 volt 3 phase Switchgear

[jimmac49]

We have a design that was submitted for approval. There are two 5000 amp. main breakers supplied from different transformers with a N.O. tie between them. My concern is that the tie breaker is located on the second floor apart from the mains. There are two 5000 amp. bus ducts connecting the two mains to the tie breaker. Other then being an odd line up is there any ANSI Standards or Code violations that would prohibit this arrangement? Also anyone have an idea what 5000 amp bus would cost per ft. There is a couple hundred feet of bus duct required to do it this way. Thanks

Jim

 

[ron]

Are there interlocks to ensure an open transition?
If not, have you considered whther the two sources could be out of sync and the total fault current with both sources?

 

[jimmac49]

Ron, they are interlocked. Thanks

 

[zog]

We have a design that was submitted for approval. There are two 5000 amp. main breakers supplied from different transformers with a N.O. tie between them. My concern is that the tie breaker is located on the second floor apart from the mains. There are two 5000 amp. bus ducts connecting the two mains to the tie breaker. Other then being an odd line up is there any ANSI Standards or Code violations that would prohibit this arrangement? Also anyone have an idea what 5000 amp bus would cost per ft. There is a couple hundred feet of bus duct required to do it this way. Thanks

Jim

What was the reasoning for putting the tie on a different floor? Space?

 

[jimmac49]

Yes, there is no space

 

[HCC]

We have a design that was submitted for approval. There are two 5000 amp. main breakers supplied from different transformers with a N.O. tie between them. My concern is that the tie breaker is located on the second floor apart from the mains. There are two 5000 amp. bus ducts connecting the two mains to the tie breaker. Other then being an odd line up is there any ANSI Standards or Code violations that would prohibit this arrangement? Also anyone have an idea what 5000 amp bus would cost per ft. There is a couple hundred feet of bus duct required to do it this way. Thanks

Jim

contact me. I build custom bus duct for a living. I ca help you.
Tony Humbert

**Contact Info deleted. Please contact this person via PM**

 

[jdsmith]

We have a design that was submitted for approval. There are two 5000 amp. main breakers supplied from different transformers with a N.O. tie between them. My concern is that the tie breaker is located on the second floor apart from the mains. There are two 5000 amp. bus ducts connecting the two mains to the tie breaker. Other then being an odd line up is there any ANSI Standards or Code violations that would prohibit this arrangement? Also anyone have an idea what 5000 amp bus would cost per ft. There is a couple hundred feet of bus duct required to do it this way. Thanks

Jim

A couple hundred feet of 5000A bus? We have a project now with 3 double ended 480V lineups. That entails 4 pieces of 4000A bus about 20 feet long and 2 pieces about 30 ft long. I can check cost on that 4000A bus on Monday and give you some idea.

As far as a code issue with having the 3 source breakers in an autotransfer scheme in 2 different places, I think you're OK as long as you fall under the "industrial complex with established procedures for maintenance" category. If you're not in that category I'm not sure. We have two projects planned right now to double-end two existing single-ended switchgears in which the tie, main 2, and bus 2 would be located in adjacent structures from main 1 and bus 1.