i HAVE BEEN ASKED TO QUOTE ON A BACK UP GENERATOR INSTALL.MY QUESTION IS,TWO BUSINESS,S WANT TO SHARE THE COST OF ONE BACK UP GENERATOR FOR BOTH BUSINESS,EACH UNIT HAS A 100A 120/208 3PHASE PANEL AND BOTH HAVE THEIR OWN METERS.IS THERE AWAY THAT EACH CAN HAVE THEIR OWN TRANSFER SWITCH.HAS ANYONE DONE A PROJECT LIKE THIS?
I HAVE PHONE THE ELECTRICAL INSPECTOR AND IAM TALKING TO HIM IN THE MORNING.IS THIS PROJECT POSSIBLE OR IS TWO BACK UP GENERATORS REQUIRED?
THIS PROJECT IS ON VANCOUVER ISLAND (NANAIMO)

I think your caps lock is on

Never done it or seen it, but I like it.

They would have to have their own Transfer Switches.

I'm wondering if you are allowed to tie two separate loads to one set of Generator lugs... unless the Generator has Load1 AND Load2... and they are split evenly?
Like I said, I've never done it..

I'm thinking... feed a panel(outside, or in a shack) and sub-feed the two Transfer Switches from there..

There is another Generator topic, where the neutral was brought up... If the Generator has it's own main ground and bonded neutral, then the neutral needs to be switched in the Transfer Switch along with the feeds. 4 pole breaker in your case.

Anyways, a few things to run by Inspector.

I'm interested to know how this will turn out
Good luck.

What are the loads? Is the standby on the same property fed from the same utility service?
Any emergency loads like exit lights, smoke fans, fire fighter elevators, emergency lighting needs a seperate transfer switch, Fire pump needs a seperate transfer switch, Standby power for non emergency use like a computer or refridgerator requires a separate transfer switch.

From your post I am guessing this is just for standby power and no emergency systems? You can build a small emergency distribution too. 1 main to 2 distribution breakers or switches and 2 transfer switches to each unit with a normal and standby feed in with a protected feeder out to the regular panel. If you are not protecting all the circuits in each unit then you need to add another panel with just protected circuits installed. Remember the generator must be sized to carry all the load connected to it. So for example you have 100 amp out put and each space has a 100 amp panel the generator can only carry 50 amps for each so there would have to be a protected panel and only circuits up to 50 amps could be connected in a power failure in each unit. that requires a bunch more work and profit too.
So start with the loads and work back to the generator.

Have fun and get smarter at the same time.

I talked the electrical inspector this morning and he felt that the only way to do this project is to feed both business's from one load centre and use one transfer switch and two sub panels.This for a Dr. office and a pharmacy.The loads are lights two fridges and all the PC equipment.The load is about 35amp per business.The problem with using only one panel to feed both business,s is thatthis load will only be metered by one business.Would two ups be a better solution?
Jack

First there is no requirement to meter the output of the generator, the utility does not make you pay for electricity you produce. They just don't want you to give it to them without a whole lot of safety requirements.
The utility does not want to charge 2 customers for their electricity through 1 meter they want 1 for each customer and the Code requires this in most cases.
Each customer gets normal through a meter and to a load center through the normal power in the transfer switch.
The generator can have two output breakers or 1 to a combination panel with two load breakers. one to the dentist transfer switch and the other to the pharmacy transfer switch. In a power failure the generator starts, both transfer switches transfer the power to the generator and the utility is disconnected until normal power is restored. the generator shuts off and customer pay hydro again. It is the responsibility of the customers to share the maintenance cost of the generator and its fuel.
2 utility services and 1 generator with two loads.
Private message me and I'll fax you a diagram you can take to your inspector

Metering?

Put meters on the sub-feeds to each building.
I could see needing them, if one business goes out, and the other doesn't.
But that decision should be up to the customers, and how willing they are to trust.

I don't like your inspectors idea.

I can see why two TS's may be an issue though.... if one is paranoid that the two hydro services could somehow short to eachother.... but that would be a miracle.

Ups? personally, I wouldn't upsell those to my customers. I'd find a deal on two generators, if I had go that route. Probably cheaper anyway. Fancy things break easy.

Good luck

One generator, 2 transfer switches is the way to go. We have used 3 or 4 switches with one genset before. With multiple switches if something happens to the utility service lateral(drop) on one building it can start the genset and be powered that way, without powering all buildings. The transfer switch start wires are connected in paralell so any switch can start the genset, but power has to be restored to all of them before the genset will shut down. Never had any problems doing it this way, but I am not in Canada. just my 2 cents.

They may be willing to split the costs for installation, but if the only thing that they are sharing is the generator, each tenant can take responsibility for installing and maintaining their own ATS.
That way the only business penalized for neglecting their maintenance would be the one who is fed from it, inlcuding everything in their branch of the generator system.
I'd run the generator output to either a tap box or a small panel (check with the AHJ) and then to each tenant's panel via their own individual ATS.
BTW, tell them that they will need a small plug-in UPS for anything that's PC-based. The brief outage that they will get when switching from Utility to generator will be enough to shut down the computers and they'll lose their work and need to restart them. If the electrical system is feeding the UPS, the computer will never see the outage.

They may be willing to split the costs for installation, but if the only thing that they are sharing is the generator, each tenant can take responsibility for installing and maintaining their own ATS.

They will also be sharing the costs of maintenance, fuel, insurance, liability, inspections, etc.

That's a good point, Larry.
I was just trying to point out that it's a good idea to minimize the amount of shared stuff. If you're sharing 1 ATS with other people who turn out to be deadbeats, you're up the creek. If their frugality only hurts them but leaves your store in good shape, so much the better.

I install mostly Generac and Kohler sets, either can be ordered with lugs on the breaker that will accept multiple wires, eliminating the need for a dist. panel or wireway. Each tennant can have a complete run from genset to transfer switch with no joint in it.

Thanks for all the good info guys,I will order a generac with the extra lugs on the breaker,if I get this contract.They want
the generator mounted on the roof of the building,what is the best way to install it on the roof?

Before you can mount the generator on the roof there are few thing you will need to check it out with the building engineer to make sure they can support the weight of generator unit and other requirement needs.

and get a rough idea how big the generator size wise you want and let us know or concat the generator manufacter they will give you a listing of weights of the units and footprint size as well so you will know much weight it will sit on the roof.

I am not too suprised there are some case you may have to add addtional support braces or beams to handle addtional loads.

And mount them with viberation isolators to keep the noise down.

If this is Natural Gaz it is not too bad but with Diesel fuel you may have to find a way to bring up fuel to the unit so that is the other item you may have to look at it.

I have installed couple units on the roof and I will say run by the buiding engineer first to make sure they can support as I mention earlier.

Merci.
Marc

Marc is sure right about that!
I put a 450kW unit on the roof of a lab building and it involved the structure, vibration, and a host of other issues. They even had to coordinate the generator testing schedule with the lab's experiments because the vibration was enough even through the isolators to disturb the mixtures that they were working on.
Subsequent maintenance was a nightmare working on a generator in the rain and winter on the roof; not to mention that fact that they kept getting visits from the local authorities whenever it ran because the sound traveled to houses over a block away since the genset was on the roof.
Oh, and the Fire Department would only accept it if it was natural gas. No way were they going to buy off on a rooftop fire that could drip diesel fuel down from the roof of a burning building.