Bus Tie

[mstrlucky74]

The one-line shows feeders tag( 5 sets conduits) to be run from the main swbd MS-A to new 1600a switch and then to SWBD-A-B1 but the floor plan makes it look like the switch and gear are going to be set right against each other and bus tied. I assume those could be the two scenarios...?? Would they really "nipple" 5 sets if they decided to put this equipment right next to each other?

 

[templdl]

The one-line shows feeders tag( 5 sets conduits) to be run from the main swbd MS-A to new 1600a switch and then to SWBD-A-B1 but the floor plan makes it look like the switch and gear are going to be set right against each other and bus tied. I assume those could be the two scenarios...?? Would they really "nipple" 5 sets if they decided to put this equipment right next to each other?

Done often. The key is an accurately made bus transition section between the two. Consider the cost of having a qualified person the measure the existing switchgear if a set of drawings are not available to be provided to the new gear manufacturer who would engineer and supply the transition section. If not done right it could in up being a real can of worms. Think the job through.

 

[infinity]

Is MS-A a service switchboard? I ask because I don't see a main and if it is then the new disconnect switch puts you over the 6 disconnect rule unless one of the existing switches meets the exception to the 6 disconnect rule.

 

[Smart $]

Is MS-A a service switchboard? I ask because I don't see a main and if it is then the new disconnect switch puts you over the 6 disconnect rule unless one of the existing switches meets the exception to the 6 disconnect rule.

I agree.

 

[mstrlucky74]

Is MS-A a service switchboard? I ask because I don't see a main and if it is then the new disconnect switch puts you over the 6 disconnect rule unless one of the existing switches meets the exception to the 6 disconnect rule.

It is. What is the 6 disconnect rule? No more than 6 disconnects in a service switchboard?

 

[mstrlucky74]

Is MS-A a service switchboard? I ask because I don't see a main and if it is then the new disconnect switch puts you over the 6 disconnect rule unless one of the existing switches meets the exception to the 6 disconnect rule.

Found good article..

http://www.ecmag.com/section/codes-standards/rule-sixes

 

[jim dungar]

Cable, or busway, connection between a separately mounted main breaker and a distribution switchboard has become common as an Arc Flash Incident Energy mitigation method.

 

[infinity]

It is. What is the 6 disconnect rule? No more than 6 disconnects in a service switchboard?

Yes, look at 230.71. {2008 NEC}