Large residential auto backup generator

[Strummed]

Hey guys, nice forum you have here.

I have installed a few residential automatic backup generators, but I have a new situation coming up that I would appreciate some advice.

A friend who is also a contractor gave me a good lead to a job that is a bit too big for him, I'd like to take a shot at it. Right now I only know what he has told me, I won't go look at the job until Thursday, but I would like to have some ideas ready so that I could take a better look at the house for what I need.

It's a $4mil house with a 600A service. There is a 600A main breaker MDP with 9 branch circuits ranging from 100-200A feeding individual panels around the house. There is an elevator and front gate that the person wants powered by the generator because they are disabled. I am not sure what else they want to be on the generator, I assume as much as they could reasonably get.

A 600A ATS is going to cost an arm and a leg and then it will involve way too much load shedding unless I install a monster generator. I've never done it before, but I have been told that you can link multiple Generac ATS's together and run them off of one generator. Can you do this with Kohler's too? I would prefer Kohler, I was told that the customer isn't too fussy with money and would rather pay more for something better. Is there a limit to how many ATS's you can parallel? If I could use 3-4 ATS's to power 3-4 of the 9 panels, that would probably be enough for the customer, or so I am assuming.

I'd appreciate suggestions on this. I will learn a lot more after I go see the job and find out exactly what she wants to run off the generator, but for now I'm just trying to figure out the different routes I can take.

 

[Strummed]

 

[augie47]

Keep in mind that Art 702.5 requires that your generator must be sized for the calculated load when using an ATS.
The cost of a 600 amp ATS would be insignificant compared to the cost of a 100kw generator
From your picture it appears you might have sub-panels in various locations so I can see a real challenge.
Sound like you and the owner need to determine which panels need to have the back-up and go with the multiple ATS as you mention unless momney is no object.

 

[Strummed]

Augie, I agree 100% about the generator size for a 600A ATS. That's what I meant when I said that I would have to do way too much load shedding (to avoid such a huge generator).

I posted a picture, apparently you saw it since you mentioned it in your post, but I can't see it? :?

 

[infinity]

I would check with your supplier. If you're looking at buying multiple ATS switches and a generator I would assume that you're using someone who's familiar with multiple ATS installations. You can check out these guys in Northern NJ. And IMO I would stay away from Generac.

http://www.electricalpowersys.com/

 

[Strummed]

Up until now the biggest I have installed was 20kw and I have purchased all of them from Norwall's since they beat the prices on all the supply houses that I have tried.

I am going to try EPS, thanks for the reference.

 

[gk351]

I would find your nearest Caterpillar or Cummins Power Gen dealer. They will be able to do this the right way, and especially if cost is not a huge issue. I have seen I believe 2000 Amp Cummins ATS, (I have worked in 1600A units). But I agree this is past a generac type install, and it would be well worth the money to do it right! just my opinion....

 

[Strummed]

I would check with your supplier. If you're looking at buying multiple ATS switches and a generator I would assume that you're using someone who's familiar with multiple ATS installations. You can check out these guys in Northern NJ. And IMO I would stay away from Generac.

http://www.electricalpowersys.com/

You use EPS as a supplier or you sub out to them?

 

[ceb58]

If I could use 3-4 ATS's to power 3-4 of the 9 panels

With Generac they say no more than 3 ATS.

 

[infinity]

You use EPS as a supplier or you sub out to them?

I haven't used them but I have a friend who's a local electrical contractor who uses them as a supplier (he installs Cummins Onan for most of his clients). They also provide the start up which is best left to a pro.

 

[shortcircuit2]

Looks like you have room for transfer switches near the main panel. Relocate the feeders from the main panel thru a transfer switch for each sub-panel. I prefer Kohler equipment. You could consider multiple smaller generators sized for the loads and shut generatos down when not needed in those areas to save fuel consumption.

 

[Leestarkweather]

Multiple Generacs

Multiple Generacs

First of all, Generac only makes 3-phase gensets for their "mod power" line, which each have an output contactor, and you can parallel them without paralleling switchgear.
Next, the smallest size is 300KW (Each genset) on natural gas, 400KW on diesel. Only the 300KW size comes in 208Y/120V, all bigger ones are 480Y/277V. It looks like your Sq D. I-Line panel is single phase (as would be normal for a house), so I don't think you are going to be able to parellel gensets.

I put in twin 400A diesels about 10 years ago, they do work.

This is a Sec. 702 (Optional Standby) application. You have room to reroute some of the many panel feeds to a new dist. board (300 or 400A?), then install one ATS and a genset to handle those loads. It is much cheaper to put in the generator fed sub and one ATS than multiple ATS's. And to feed multiple ATS's you would need a dist. panel for the output of the genset, with a generator feeder CB for each ATS. Soon you will have that room filled up, and spend lots and lots of $$$. You only need to feed whatever panels the customer wants for their use in an outage, not the whole load of the house.

Good Luck. I, too, would recommend CAT, Cummins, or Kohler. After more than 30 Generac Installs, IMO they are not that great.

 

[shortcircuit2]

And to feed multiple ATS's you would need a dist. panel for the output of the genset, with a generator feeder CB for each ATS. Soon you will have that room filled up, and spend lots and lots of $$$.

I don't use a "dist. panel" to feed multiple transfer switches from a gen-set feeder. All I use is a juction box to split the feeder from a gen-set into the multiple transfer switches.

 

[masterinbama]

Can you get a 120/240 3 phase delta unit large enough to carry the whole load? I know they make them as I put one on a large single phase radio transmitter site not too long ago.

 

[Strummed]

Right now I am still not sure if that is 3 phase or not. I'll find out more tomorrow when I actually look at it myself.

 

[shortcircuit2]

You had better consult with the gas company. Someone posted on another Forum that so many generators are being installed in NJ, that the street gas isn't able to supply the demand.

 

[hillbilly1]

Can you get a 120/240 3 phase delta unit large enough to carry the whole load? I know they make them as I put one on a large single phase radio transmitter site not too long ago.

Kohler is pretty good at having multiple outputs by just changing taps, can't say that about Generac. The Kohler I have is configurable for 480 wye, 120/240 delta, or 120/240 single phase by just rearranging the generator leads.

 

[Strummed]

I got a look at the house today, although we were rushed out by the homeowner because of the snow. It's 120/240V single phase.

My helper took pictures of the elevator eqipment, but I am having a hard time making it out on my old crappy computer. Can anyone make anything out on these?

The first 2 are from the panel on the wall and the compressor on the floor:

http://tinypic.com/r/zn97xg/6
http://tinypic.com/r/b53d4x/6
http://tinypic.com/r/v3k4rc/6

The other thing that I don't know about is the ejector pumps. I thought he had pulled them (how gross, ewww) but he only wrote down some info from the panel. There's 2 pumps with 25A Square D QO breakers.

I'd hate to have to go back...

 

[John120/240]

I can't tell diddly squat about your pictures. Zoeller pumps are a popular reliable brand. Here is a link http://www.zoellerpumps.com/ProductByCategory.aspx?CategoryID=2