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Drive panels in arc flash hazard analysis.
https://brainfiller.com/arcflashforum/viewtopic.php?f=4&t=472		 Page 1 of 1
Author:  levans [ Wed Jun 17, 2009 8:07 am ]
Post subject:  Drive panels in arc flash hazard analysis.
I am doing my first hazard analysis and I have a question on how to handle two panels. One panel is fed from a switchboard breaker and then has a local fused disconnect switch. The panel has a main breaker, 2 vf drives and 3 small motor starters (10hp). When using the EasyPower software, do I just setup a bus with the rating of the fused disconnect or do I add a additional bus which shows the internal breaker feeding the vf drives and starters?

The second panel is similar in that is fed from the same switchboard and has a local fused disconnect. The panel itself has a main breaker and fused starters for 2 motors. Same question. Do I dog-off the analysis with a bus at the fused disconnect or do I have to drill down and show all the components in the panel? Voltage on both is 480VAC, 3 phase.
Author:  TxEngr [ Wed Jun 17, 2009 11:00 am ]
Post subject: 
For me, I would create a bus off of the fused disconnect and rate the whole cabinet for that rating. It reduces confusion and I can't think of any reason that anything downstream would require a label. Since at least one component in the cabinet has an AF rating of the incoming feed, just label the entire cabinet the same value. Same for both cabinets. Don't forget to label the fused disconnect as well since it's incoming side will have a AF boundry as well.

TxEngr
Author:  WDeanN [ Thu Jun 18, 2009 12:05 pm ]
Post subject: 
Three buses each.
One for the disconnect.
One for the bus (above the main breaker).
One for the bus (below the main breaker).

Two labels.
One for the disconnect, One for the bus (above the main breaker).
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