First Generac Install with ATS

[AC\DC]

Hello, I have a customer that has a 22kw Guardian Generac and a 100 amp Service rated ATS. He has had it for over a years and no one want to install for him.
He wants his whole house powered off this.
Went to 220.87 to determine Maximum demand load. I had the POCO get me a Maximum Demand for 4 years span. I just to see what to expect in the future. His usage has doubled. Highest this year is 27.89kw.
So was looking around the site at old post and saw they have Smart Management modules. So from my understanding they can be used on old and new Generacs.
That should take care of that problem for now.

I think I have it figured out from looking through 702 and 455.
The problem I can't seem to figure out how to come off his Meter main. This is what he has

CMBE88B200BTS | Eaton meter breaker EUSERC | Eaton

CMBE88B200BTS - Eaton Meter Breaker EUSERC Type CH, CSR2200N main breaker, Distribution section, 200 A, 120/240V, 8 spaces, 8 circuits, 22 kAIC, Surface mounting, Box size A, Al bus, OH/UG feed, 4-jaws, 1 socket, #6-250 kcmil line, #6-250 kcmil ground

www.eaton.com

If the Disconnect was separate from the meter I could make it work.
I Don't know if I would void any listing for this if I removed the load side wire feeding the main and feed the ATS. Then go back to feed the Main breaker. Would that setup also violate 230.7 They are not considered service conductors any more past the ATS correct. Cause they only way to feed that Main breakers is to come in from the meter side.

Also I asked my AHJ about the house being oversized for the Generator. He told me the Generator Disconnect that is 100amp will protect the Generator from overloading. Is that true. The Generator at 91.6 amps will have to run for a while past 100 amps to trip the breaker.. Does not seem safe. Was wondering about that.

Thank you for any help. I have 4 customers that need this done and until I do one I won't be confident.

 

[RD35]

Okay, so here is what I know at this point. Customer has a 200A service with equipment you listed above. Now I will make assumptions and you can tell me if I get any of this wrong. Your customer has a 22KW Generac Guardian air cooled generator and a Service Rated 100A Smart Transfer Switch. Is the switch a model number RXSW100A3? If so, then it has load shed capabilities built into it.
So, first about the service. Most likely you cannot rewire the conductors within the that meter/panel without losing the listing on it. My opinon is to avoid doing it that way.
As for overloading the generator, the generator disconnect should, indeed, protect the generator although it might be better to use the load shedding features in the switch for added protection. You could also purchase smart management modules (SSM's) (if the switch that he has is not what I assumed...and has no load shed capabilities). However, those modules do not function when on utility power. They only work on generator power. How...you might ask? Well...those SMM 's sense frequency. When the generator load increases to the point it pulls down the engine speed (frequency) to below 58hz then the module opens the circuit to which it is attached....like, say, a water heater or A/C load. Utility power always stays at 60hz and cannot activate the load shed. The load shed function inside the RXSW100A3 switch works the same way. So you cannot protect from overloads by using these load shedding devices when in utility power.
If you already know all of this then I apologize for the long post.
As for your question about how to come off the service, I'd just put a 100A breaker in the main 8-circuit panel and feed the transfer switch utility lugs from that 100A breaker. If there is more than just one branch feeder/circuit being fed from from the service panel then I'd set a 125A MLO sub panel and extend the circuits in the main panel over to the sub panel. Lastly, I'd remove the bonding jumper in the transfer switch since it's not being used as the service entrance. Only thing strange would be the fact that you are feeding a 100A breaker from a 100A breaker....Duplicate over current protection...but it shouldn't be a problem.

 

[RD35]

Oh also, if your demand calc method is to be from 220.87 then my suggestion above needs to be changed to a 150A breaker and feeder...and the 125A subpanel needs to be a 200A. (Sorry I got so wrapped up in answering the generator part I didn't look closely at the service calc stuff....my bad.)

 

[AC\DC]

This is his ATS

Generac Power Systems - PWRview Automatic Transfer Switch

Generac Guardian Series home generators are the #1 selling line of home generators in the United States. Find out why!

www.generac.com

If i come off the Panel with 100amp and feed the ATS on N1/N2.Then i have to go back to the panel with another 100 amp from T1/T2 that is what your saying correct.
I got so hung up on trying to use the service condutors.

The smart managment moduals from what i read will only kick load off like you said when it hits 58hz for 3 seconds or 50hz for 1/2 second. When the generator is off they still supply power to what might latter be shed.
Just started reading the manual for the smart managment
Thanks for the reply .

 

[hillbilly1]

What I have done with Generacs before they had the smart module, was to put a RIB relay powered from the utility sense fuses in the tswitch. Interlocking whatever loads I need to shed while on generator (usually the emergency heat strips if it is a heat pump)

 

[AC\DC]

I have more research and thinking to do. If I was to come off with the 100 amp from the meter main. I can't then back feed the Meter main with another 100 cause if you turn the 100 feeding the ATS off you could have both Gen and power running at same time. I could interlock them but than that makes The ATS kind of useless.
Don't mean to ramble. Got not one else to talk to
.

 

[hillbilly1]

Hello, I have a customer that has a 22kw Guardian Generac and a 100 amp Service rated ATS. He has had it for over a years and no one want to install for him.
He wants his whole house powered off this.
Went to 220.87 to determine Maximum demand load. I had the POCO get me a Maximum Demand for 4 years span. I just to see what to expect in the future. His usage has doubled. Highest this year is 27.89kw.
So was looking around the site at old post and saw they have Smart Management modules. So from my understanding they can be used on old and new Generacs.
That should take care of that problem for now.

I think I have it figured out from looking through 702 and 455.
The problem I can't seem to figure out how to come off his Meter main. This is what he has

CMBE88B200BTS | Eaton meter breaker EUSERC | Eaton

CMBE88B200BTS - Eaton Meter Breaker EUSERC Type CH, CSR2200N main breaker, Distribution section, 200 A, 120/240V, 8 spaces, 8 circuits, 22 kAIC, Surface mounting, Box size A, Al bus, OH/UG feed, 4-jaws, 1 socket, #6-250 kcmil line, #6-250 kcmil ground

www.eaton.com

Also I asked my AHJ about the house being oversized for the Generator. He told me the Generator Disconnect that is 100amp will protect the Generator from overloading. Is that true. The Generator at 91.6 amps will have to run for a while past 100 amps to trip the breaker.. Does not seem safe. Was wondering about that.

Thank you for any help. I have 4 customers that need this done and until I do one I won't be confident.

Being a Generac, I doubt you would reach even 90 amps before the motor shut down! LOL!

 

[AC\DC]

Thank you for help. Re read the post and sat down and drew it out. makes sense now.

 

[Stebs]

Is this propane or nat gas? The Generac’s don’t put out full capacity on nat gas. The 22’s (I have one too) are only rated to like 18.5 or 19kw on nat gas.

Also, did your customer piece this combo together? I thought the 22kw kits came with a 200 amp switch.

 

[AC\DC]

Its propane. owner bought all parts at once from a dealer

 

[Strombea]

We do this all the time. As far as the confusion on the panels and transfer switch,
You have to take all loads and put the in a sub panel, the load side of ATS feeds sub panel
there is no need or a way to back feed meter main. Generac sells wireless load shed modules too. They also sell a ATS combo with a 20-30 space BR sub panel. This allows for using less wall space.

 

[AC\DC]

Thanks for the Input. How's the drawing look. Will just splice in the Old meter main. For the house wire and Sub panel.
Thanks again.