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URGENT :( connecting Motivator/Generator to Switch then to MCC
2

URGENT :( connecting Motivator/Generator to Switch then to MCC

URGENT :( connecting Motivator/Generator to Switch then to MCC

(OP)
I am pretty new in this forum and also pretty new in the electrical stuff.
I just got assigned a project and basically, I need to come up with a back up power for some MCC we have in here.
We working on a 4160V line. We have a portable motivator (generator) and I am about to order an Automatic Transfer Switch. I have already sized all the cables (from Motivator and pole to Switch, and from switch to MCC).
However, I am a little confused on the CONNECTION. Besides the cables, what do I really need to connect the motivator or pole to the switch??
I was told I might need some sort of receptacle male and female.
This might sound elementary to you guys since you are advanced in this but this is my first time.

RE: URGENT :( connecting Motivator/Generator to Switch then to MCC

If it is possible to connect the cable from the generator directly into the ATS that would save you some money on the plug/receptacle.

On the other hand, it is much quicker to disconnect and relocated your portable generator if it was connected vita a plug and receptacle. The maximum i hear of is rated for 30A, which at 4120V is roughly 200kVA...

up to your budget, conditions of installation, frequency of mobility, permissible down time while connecting disconnecting cables, you urgency to have the installation up and running or  just placing the order.

I wonder how you sized the cables if you are new to electrical stuff, have you sized the circuit breaker in the ATS as well, did you specify what metering or protections you want in the ATS.

RE: URGENT :( connecting Motivator/Generator to Switch then to MCC

(OP)
Thanks Auslee for your reply.
I do have experiences in cable sizing from school and my few first weeks at work.
The budget is not the main issue since the company has to implement it.
The ATS will be made by GE and it's breaker should be a 500-600A I believe. But the manufacturer is taking care of it.
I would rather use the receptacle to connect the Generator (2000KVa, 4160V, 277A rating) to the switch.
But, how do I select the appropriate receptacle?

RE: URGENT :( connecting Motivator/Generator to Switch then to MCC

I think it is going to have to be hard connected.  At medium voltage things are far different than at low voltage.  You could provide bus bars that the connections bolt into, but you're not going to find a plug and receptacle (at least not that I'm aware of).

RE: URGENT :( connecting Motivator/Generator to Switch then to MCC

(OP)
davidbeach,
that bus bar you mentioned. are we going to have one in the generator and one in the switch ?

RE: URGENT :( connecting Motivator/Generator to Switch then to MCC

I hate the idea of "plugs" in Medium Voltage! Think it through a little, someone could theoretically be walking around with a live plug in their hands, looking for a receptacle? Not in my world!

But that said, they are made.
http://pfisterer.com/p-mvconnex.php?nav=cablesystem&bc=710&land=19

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RE: URGENT :( connecting Motivator/Generator to Switch then to MCC

I've used MV plugs and receptacles before as well.  Usually these will have some low-voltage pilot connections that must show continuity to allow energization of the assembly.  Because these wind up being 15" long and wiegh 40 pounds or so, people generally don't wander around with them looking for a connection.  The plugs and receptacles should be purchased with insulated dummy covers.  The locking rings are drilled and so can be locked into position.

RE: URGENT :( connecting Motivator/Generator to Switch then to MCC

You will need two or more control wires from the generator to the ATS to start and stop the Gen set. Ground fault protection may be an issue. You may be able to use a solid neutral, but some ground protection schemes will require the use of a four pole transfer switch.
A three pole transfer switch is cheaper and avoids possible open neutral issues. I have seen damage done a couple of times by an open neutral in a neutral switched transfer switch.
If you have a three pole system you should be good with a three wire transfer switch.
Even though you may have a three wire system, some three wire systems may require a neutral conductor to be run from the generator to the main panel for metering and/or protection.

Bill
--------------------
"Why not the best?"
Jimmy Carter

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