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Motor Circuit
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Author:  Kimo [ Mon Nov 07, 2011 10:36 am ]
Post subject:  Motor Circuit

I have an existing contrition and conflicting opinions as to whether this is Code compliant or not. Please take a look at the attached PDF and comment on the wire and circuit protection sizing. Is this correct, Why or Why Not?

Thanks!!!

Attachments:
PDP Example.png
PDP Example.png [ 22.23 KiB | Viewed 7523 times ]

Author:  glen1971 [ Mon Nov 07, 2011 8:48 pm ]
Post subject: 

- What type of wire are you using?
- By "2-1/C-4/0" do you mean 2 parallel runs of 4/0?
- Are there any other settings on the ABB S6H breaker?

By a quick look it looks not bad, but the more info you can provide the better...

Author:  Kimo [ Wed Nov 09, 2011 2:12 pm ]
Post subject: 

Further Clarification

Thanks for your reply Glen,
Let me shed a little more light on the situation & system (I had asked the question very open/generalized as to not to lead anyone, I wanted honest interpolations/options first). This is an existing system that we are performing an Fault Current, Coordination & Arc Flash Hazard Study on. During a review the existing circuit breaker sizes vs. the wire sizes were questioned and it was suggested that the either the wire sizes or breaker sizes needed to be changed, but this is not everyone’s option. Some believe that from the Switchboard to the Starter cabinet is a feeder others believe this is a Motor Branch Circuit. I can not find in the Code where it makes a clear distinction as to how this particular installation/application would be classified. Any further clarification or comments would be greatly appreciated. See the attached sheets for more detail regarding the existing installation.

Attachments:
Logo FlashTrack 8-15-12.jpg
Logo FlashTrack 8-15-12.jpg [ 9.79 KiB | Viewed 7494 times ]

Author:  glen1971 [ Thu Nov 10, 2011 6:33 am ]
Post subject: 

Thanx for the additional info... I did some checking with a program that is one of the best I've used for voltage drop, and conductor sizing. It shows that the conductors are sized properly for the load. I have included the link for the program I used..

http://www.mc-group.ca/voltage_drop_calculator.htm

As I am from Canada, I'm not sure that any code clarification I could provide would be relevant. I guess the easiest way I would determine if it was a feeder or a branch circuit (from the switchboard to the starter) would be - what if the starter was another distribution panel, then what would it be called? What if it went to another distribution transformer, what would it be called? In my thinking, it doesn't matter and is a feeder...

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