800 amp question

[milemaker13]

We will be installing a new press line in the near future. The press itself requires a 200 amp 480v service. There will also be ancillary equipment suck as a decoiler, straightner, feeder, stacker, ect.

Future planes also call for a coil sheeting line.

Our main service panel in this building has an 800 amp breaker that was installed for this project. My question is how to best handle the 800 amps from the main panel to the new press area.

I was asked to provide the 200 amp drop for the press. I figure I have 2 options: Buy more breakers for the service panel and run everything individually, or bring the 800 amps to the area and use a tap box to power two 400 amp breaker panels.

I am leaning towards the tap box and using either 400 amp breaker panels, or seperate fused disconnects for each machine.

The main panel is about 140' from the press area. I'd be looking at maybe 170' of pipe to run a tap box situation (depending of course where thay decide to put this electrical equipment.

For 800 amps I would plan to use two networks of 500mcm cable each in 3" EMT.

Thoughts?

 

[petersonra]

I am a fan of running one feeder over multiple branch circuits just because it is almost inevitable that you will end up needing more branch circuits in the area down the road at some point and it should be simpler to add them locally.

In this case it is only a relatively short distance so it is not as big of a deal. If cost wise it is not all that much difference, i would be inclined toward running the feeder.

To save some money you might want to consider installing only one of the 400A panels at this time, although the guts of one without breakers probably is not horribly expensive.

Is it cheaper to run pairs of 500MCM over six 1/0s?

 

[Smart $]

Probably best to "distribute" closer to area of use.

Another option is to put two 400A breakers in main panel and a run of 500's to each of two 400A MLO panels.

 

[MarineTech]

We will be installing a new press line in the near future. The press itself requires a 200 amp 480v service. There will also be ancillary equipment suck as a decoiler, straightner, feeder, stacker, ect.

Future planes also call for a coil sheeting line.

Our main service panel in this building has an 800 amp breaker that was installed for this project. My question is how to best handle the 800 amps from the main panel to the new press area.

I was asked to provide the 200 amp drop for the press. I figure I have 2 options: Buy more breakers for the service panel and run everything individually, or bring the 800 amps to the area and use a tap box to power two 400 amp breaker panels.

I am leaning towards the tap box and using either 400 amp breaker panels, or seperate fused disconnects for each machine.

The main panel is about 140' from the press area. I'd be looking at maybe 170' of pipe to run a tap box situation (depending of course where thay decide to put this electrical equipment.

For 800 amps I would plan to use two networks of 500mcm cable each in 3" EMT.

Thoughts?

In terms of layout, please consider NFPA 70E and NFPA 70B. Look at electrical safety, ease of repair and maintenance as important items per the overall install.

MarineTech

 

[milemaker13]

OK, so we all seem to think its a way better idea to just run the feeder for several reasons. I agree. I will probably go with the 800a breaker simply because it is alreay installed. I will probably only install one breaker box at this time.

I will have to compare cost of running two 500s, four 3/0 and six 1/0. I'll also have to check the installed breaker to see how many terminal holes it has. That is a good suggestion, thanks.

In reguards to 70E (which I am at least fairly familiar with) and 70B (which I am not): What in particular are you looking at? I will go ahead and read up some more, but what do you have in mind?

The tap boxes we installed for our laser systems are nice manufactured units. But if I under stand correctly, I can use a standard large J box and split bolts. Yes?

Keep it coming- I really appreciate it!:thumbsup:

 

[ptonsparky]

I have found that a panelboard complete with breakers is a good deal less expensive than a panelboard alone, or just a couple breakers, so if you have any idea at all about future needs, order them now.