Temp generator hooked to bus bars wires live on normal power

[hockeyoligist2]

We have a temporary generator 480v directly connected to the bus bars on a mcc. So the wires, which are laying on the ground and floor are energized while on normal power.

We have a power share agreement with poco. Due to the unusual cold weather they are requiring us to operate the gen on a one hour notice, not enough time for an electrician to respond, make up the connections and get poco offline.

There are concerns of safety with this setup. It is basically the same safety hazard as a drop cord, only 480 v, which scares non-electricians. The breaker on the gen is locked out to prevent any non-qualified (our electricians) to turn it on, which would be a disaster if the poco side was still on!

I'm not completely comfortable with the setup myself because things happen.

Thoughts?

 

[Jraef]

Is your concern here just the power cords on the ground? I have other issues but I don't know if you have already addressed them.

But to this cord issue, it's done all the time in portable power plants for things like on-site rock crushers, construction compressors etc. I typically put the cables in a trench, then cover them with a 1/2 culvert and gravel, but that's because I would have tractors and equipment driving around.

 

[petersonra]

Is there a transfer switch involved so that only either the generator or POCO can supply power? the "directly connected to the bus bars" statement makes me pretty nervous.

I don't really care about the cords much, as long as they are not subject to damage.

 

[mikeames]

which scares non-electricians.
Thoughts?

480 Sacres me to....

On a serious note as you indicated its a potential bomb if both are online at the same time. It would seem to me that there needs to be another step aside from just a LOTO breaker.

What size generator is this, or what size are these wires on the floor? I am trying to get a feel as to how these are tied to the buss.

 

[ceb58]

The thing is 702.6 Exception allows for this set up. As long as the cords are rated for the voltage and conditions then it is OK.

 

[Thedroid]

Nothing wrong with it as long as only responsible people are going to be performing the switch. Make a procedure checklist and have one person read the steps and another follow them. I hooked up a generator the exact same way earlier this year to a 1500 kva transformer while we worked on the incoming MV bus.