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Discussion Starter #1
I have only done a few of these in my short time in biz and they were very straight forward for small houses. I'm currently trying to size one up for a larger house with multiple A/C units. Any tips or tricks of the trade from those of you who have done a lot. Not sure I trust these sites that tell you how to size them up. Think they just want you to buy a bigger genny so you spend more.
 

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What's the calculated load on the house?
What appliances are electric?
How many AC units?

How many AC units does the customer want to be able to run?

Typically, I just use a Generac 22KW (it's new, before that I used the 20KW) and load shed whatever I need to in order to bring the load down to the generator's rating.
 

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evil bastard
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Dude, if you don't do many do yourself a huge favor and wait until March to purchase it. Generac has a new load shed module that is totally awesome and will be available in march. No more load managing from the transfer switch. No more wires to each piece of equipment. I'm totally psyched.
They also have new wire available for up to a 22kw. Its one big cable with all the power wires and control wires all in one. Rated for direct burial. Many new good products in the pipeline. Oh, by the way the wire is available now. My new roll came in today.
 

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Dude, if you don't do many do yourself a huge favor and wait until March to purchase it. Generac has a new load shed module that is totally awesome and will be available in march. No more load managing from the transfer switch. No more wires to each piece of equipment. I'm totally psyched.
They also have new wire available for up to a 22kw. Its one big cable with all the power wires and control wires all in one. Rated for direct burial. Many new good products in the pipeline. Oh, by the way the wire is available now. My new roll came in today.
More info on this new load shedding, damnit!

Also, who makes and sells the cable? I just bought another 1,000' of tray cable :censored:
 

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evil bastard
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Generac sells the cable, I'll check the manufacturer.


Onto the load shedding, it's a self contained module rated at up to 50 amps. There is absolutely no control wiring. You run your branch circuit conductors through it. It monitors frequency and wave shape. It recognizes the wave shape when running on the genny. It will load shed that load if the frequency drops below threshold. Perfect for air handlers, heat pumps, water heaters, stoves, strip heat circuits. Absolutely no control wiring, amd they can be prioritized also.
 

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Generac sells the cable, I'll check the manufacturer.


Onto the load shedding, it's a self contained module rated at up to 50 amps. There is absolutely no control wiring. You run your branch circuit conductors through it. It monitors frequency and wave shape. It recognizes the wave shape when running on the genny. It will load shed that load if the frequency drops below threshold. Perfect for air handlers, heat pumps, water heaters, stoves, strip heat circuits. Absolutely no control wiring, amd they can be prioritized also.
That sounds interesting. How do you prioritize them if there is no control wiring?

What about typical AC units, will there still be low voltage contacts for them? What about when you have more than 2 AC units? Will the new ATS have provisions for connecting relays?
Thanks.
 

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evil bastard
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That sounds interesting. How do you prioritize them if there is no control wiring?

What about typical AC units, will there still be low voltage contacts for them? What about when you have more than 2 AC units? Will the new ATS have provisions for connecting relays?
Thanks.
There is a dial on the front to set the priority. I think it's done by time, like on the transfer switch. I also think the old way of load shedding will still be available inside the transfer switch.
 

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There is a dial on the front to set the priority. I think it's done by time, like on the transfer switch. I also think the old way of load shedding will still be available inside the transfer switch.
I see, so once one unit sheds the load the frequency will go back to normal. Makes sense. I like this idea.

What I really want is 4 contacts for AC units because I have had many houses with 3 or 4 units and I hate spending the money on the 50A relay and transformer just to switch the extra AC units.
 

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Small Potatoes
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Dude, if you don't do many do yourself a huge favor and wait until March to purchase it. Generac has a new load shed module that is totally awesome and will be available in march. No more load managing from the transfer switch. No more wires to each piece of equipment. I'm totally psyched.
They also have new wire available for up to a 22kw. Its one big cable with all the power wires and control wires all in one. Rated for direct burial. Many new good products in the pipeline. Oh, by the way the wire is available now. My new roll came in today.
Were you at the conference last week?
 

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Generac sells the cable, I'll check the manufacturer.


Onto the load shedding, it's a self contained module rated at up to 50 amps. There is absolutely no control wiring. You run your branch circuit conductors through it. It monitors frequency and wave shape. It recognizes the wave shape when running on the genny. It will load shed that load if the frequency drops below threshold. Perfect for air handlers, heat pumps, water heaters, stoves, strip heat circuits. Absolutely no control wiring, amd they can be prioritized also.
Got a link?


Sounds quite possible that this could be an independent unit? Do they intend to market this module as a "retrofit" for existing installs?
 

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evil bastard
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Sounds quite possible that this could be an independent unit? Do they intend to market this module as a "retrofit" for existing installs?
I don't see why it wouldn't work with most models, except for the fact that it "recognizes" the wave form to know when it's running on generator, so I really can't say if it recognizes every waveform that generac has ever created in every generator.
 

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Sure, but I would bet that what it recognizes is a waveform that is a certain % different than the POCO, which I bet is fairly standard. If so, nearly any genny would be recognized.
 

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Can't Remember
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The load shedding was pretty cool. Probably the best thing I saw. The only concern I have about the cable is the tray cable rating and not being listed for use outside of a raceway.
 

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Discussion Starter #15
What's the calculated load on the house?
What appliances are electric?
How many AC units?

How many AC units does the customer want to be able to run?

Typically, I just use a Generac 22KW (it's new, before that I used the 20KW) and load shed whatever I need to in order to bring the load down to the generator's rating.


I still need to calculate load but its a 2200 sq ft house. Water heater, range, heater, dryer all natural gas. 3 small AC units. RLA at 10a, 9a, and 8.6a. Nothing in the panel except 15s and 20s and the 2 pole 20s for the 3 AC units. 200a panel pretty full.
Customer would like everything in the house on the genny.

McClary, I wish I could wait until March for the new products but this is a rush.
 

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ET rocks
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You've got a 200A service, so you know that's your switch. i would go with the 22kW and load shed two AC's.
 

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evil bastard
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The load shedding was pretty cool. Probably the best thing I saw. The only concern I have about the cable is the tray cable rating and not being listed for use outside of a raceway.
I've been using tray cable for years now long before generac even offered it. Its legal to use outside of a raceway, just not where subject to physical damage, or underground. But it saves a ton of time in crawl spaces and basements.
 

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Discussion Starter #19
I've been using tray cable for years now long before generac even offered it. Its legal to use outside of a raceway, just not where subject to physical damage, or underground. But it saves a ton of time in crawl spaces and basements.

Any reason I cant use SER to run through crawl space from transfer sw to generator?
 
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