Convoluted service upgrade

[hillbilly1]

You're welcome. We went over such things as hole-sawing between panels to relocate generator circuits to one panel, how to fit one ATS and one disconnect in the wall-space, how to explain options to the customer, etc.

I recommended providing an estimate for a full-capacity system with a 400a ATS and 70-75kw genny, as well as a realistic system with only one panel serving loads that really can't wait for normal power to be restored.

I also suggested sitting with the customer and going over every circuit, and assign each to one of three columns: Definitely on the genny, Definitely not on the genny, and Optional depending on leftover capacity or space.

One thing I didn't bring up was the additional gas volume required for either size. A larger generator increases the likelihood that the existing gas line and meter will have to be up-sized to provide the necessary BTU for the genny.


Well, there's your 100a emergency capacity. You could either supply the 100a panel and avoid load-shedding if you can narrow down the generator list enough, or supply the 200a panel and incorporate load-shedding.

Yeah, 70-75 kw would require a 2 lb gas meter, along with a regulator of sufficient size. The 26 kw may also need an upgrade too, but from the sounds of it, natural gas may not be available because of the service and load sizes. This may mean LP.

 

[hillbilly1]

I looked up a chart earlier to find the gas supply size for various generators. Likely 1.5" or 2" for 50-60kw generator.

Most gas lines here are only 1 inch from the street. That would add a very substantial cost.

Fuel Pipe Sizing

Fuel Pipe Sizing

www.generatorjoe.net

It can be changed to a high pressure meter, so a smaller line from the street will probably be sufficient.

 

[electrofelon]

Had a good chat with @LarryFine on the phone earlier today. Good input. Thanks, brother

And I think I've got a lead on a 26kw generator that comes with a service rated ATS - thanks @electrofelon for the mention of the Smart Management Modules. Now to convince the customer that roughing it means no hot tub and no steam shower

Thanks for all the input

Yeah full disclaimer, I have never used them, but they seem super handy and easy for shedding larger items.

 

[marmathsen]

Gas usage (load?) is often a double edged sword. More gas appliances mean smaller generator. But more gas appliances also mean there might not be enough headroom on the gas service to supply the generator.

Obviously the inverse is true too. Mostly electric heating loads means bigger generator and again, there might not be enough headroom on the gas service to supply the generator (because now you have a larger generator).

You might need to do a calculation on the gas appliance BTU/CFH usage and compare it to the meter size, or have a gas contractor do it.

Rob G

 

[James L]

Yeah full disclaimer, I have never used them, but they seem super handy and easy for shedding larger items.

After looking into them a bit, they probably aren't going to work. They mount outside the panels, and they're about the size of an air conditioner disconnect. I don't have any provision for installing them because the panels are inside a finished wall.

I'm back to looking at a manual transfer switch so the customer can control the load, or full size genny.

Larry suggested a nipple or two between panels (there's one stud between them) and move circuits to have one genny panel, but I don't think I have a clear shot in both panels.

 

[electrofelon]

After looking into them a bit, they probably aren't going to work. They mount outside the panels, and they're about the size of an air conditioner disconnect. I don't have any provision for installing them because the panels are inside a finished wall.

I'm back to looking at a manual transfer switch so the customer can control the load, or full size genny.

Larry suggested a nipple or two between panels (there's one stud between them) and move circuits to have one genny panel, but I don't think I have a clear shot in both panels.

Maybe just cutting a little drywall is the solution here. I get obsessed just as much as the other guy about not cutting drywall sometimes, but really how much does a little drywall patch cost? Seems like getting some stuff moved betwixt those panels is what's got to happen. It seems like buying a giant generator is on the table but $100 drywall patch isn't?

 

[Buck Parrish]

My thoughts on natural gas generators. Are you using it for weather emergencies? Because if the US is ever attacked by another country. The utilities will be the first to get bombed. Their goes your natural gas.
While diesel and gas will still be bought and sold whether on the black market or not. Plus, you can stock up on it.

 

[James L]

It seems like buying a giant generator is on the table but $100 drywall patch isn't?

Now why'd you have to go and get all logical?

 

[kwired]

My thoughts on natural gas generators. Are you using it for weather emergencies? Because if the US is ever attacked by another country. The utilities will be the first to get bombed. Their goes your natural gas.
While diesel and gas will still be bought and sold whether on the black market or not. Plus, you can stock up on it.

LP will also be whatever you have on site plus what you are able to get after the fact. And it won't go bad in longer term storage like gasoline or diesel can.

 

[kwired]

Gas usage (load?) is often a double edged sword. More gas appliances mean smaller generator. But more gas appliances also mean there might not be enough headroom on the gas service to supply the generator.

Obviously the inverse is true too. Mostly electric heating loads means bigger generator and again, there might not be enough headroom on the gas service to supply the generator (because now you have a larger generator).

You might need to do a calculation on the gas appliance BTU/CFH usage and compare it to the meter size, or have a gas contractor do it.

Rob G

For dwellings this usually is easily solved by using higher supply pressure and placing end use regulators closer to appliances.

For LP you do have to increase tank capacity sometimes though. Too high of usage rate from a LP tank can cause lines to freeze up.

 

[marmathsen]

For dwellings this usually is easily solved by using higher supply pressure and placing end use regulators closer to appliances.

For LP you do have to increase tank capacity sometimes though. Too high of usage rate from a LP tank can cause lines to freeze up.

My utility has never offered high pressure as a possibility on past projects. We have needed to increase the supply line from the street as well as install a larger gas meter.

Although I wasn't aware of the high pressure possibility. I'm guessing they would have offered it as a solution if it was possible. But maybe you just have to know what to ask.

Rob G

 

[kwired]

My utility has never offered high pressure as a possibility on past projects. We have needed to increase the supply line from the street as well as install a larger gas meter.

Although I wasn't aware of the high pressure possibility. I'm guessing they would have offered it as a solution if it was possible. But maybe you just have to know what to ask.

Rob G

Being a possibility and not wanting to do so are two different things. They maybe have some sort of policy of not delivering anything but 7 inch WC. If so more usage means larger piping is going to be necessary.

 

[hillbilly1]

My utility has never offered high pressure as a possibility on past projects. We have needed to increase the supply line from the street as well as install a larger gas meter.

Although I wasn't aware of the high pressure possibility. I'm guessing they would have offered it as a solution if it was possible. But maybe you just have to know what to ask.

Rob G

Pretty common in the Atlanta area. There is two ways to do it, 2 psi meter (red meter face) with two large regulators, one for the house, one for the generator. But the most common is separate regulators at all of the appliances, which means the inside existing gas lines have an increase from 7-11 inches WC, to 2 psi, which may be why your utility doesn’t like to do it.