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Generac Purchase and Install Questions

timc930

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Sep 11, 2018
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Mount Pleasant, SC
Looking at a Generac 28kw air cooled generator. We had the generac 200amp transfer switch and propane port installed when we built the house. Called Generac and they sent one of their local reseller/installer out and he quoted us $15k for the generator and installation. This seems high considering I can buy the generator at Home Depot for $7k. He offered us 5% off if we signed up the day he was here telling us if we did not he might be hard to get in touch with. Sounds like a timeshare racket to me. Any reason not to buy the generator from HD and find a licensed Electrician/Plumber to install since the gas and Transfer box are already installed?
 
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steves_001

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Southern MN / Northern MN
Costco has Honeywell generators (generac rebadge). I bought a 22kw for just under 5k delivered. Propane add on piping was 750 and the electrician was about 2 k and he had the special wire to run from transfer sw to genset.
When setup to the mothership (generac) it’s all the same start up process. Costco even had extended warranty. Works like a charm and a whole lot less money. Might be worth checking that out.
 

SILVERPLATE

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Fort Worth, Texas
I bought mine from a Generac dealer two years ago for 6800 including a transfer switch and 2800 to a local electrician to install. Got the zero percent interest of the generator and got it paid off in 14 months.
 

Sumboodie

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What are you running in a house that you need 115 amps of power?

I have a 7.5kw and it's more than enough.
Heat, few lights, fridges/freezer, well pump... and still plenty left.

I can see around a 12-14kw if you have A/C and "need" it.
 

moab11

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Thunder Bay, Ontario
What are you running in a house that you need 115 amps of power?

I have a 7.5kw and it's more than enough.
Heat, few lights, fridges/freezer, well pump... and still plenty left.

I can see around a 12-14kw if you have A/C and "need" it.
Depends on outage frequency and duration. Bigger generators are liquid cooled, so handle long outages better.
If you get frequent long outages, then being able to cook and such becomes more important, and justifies the larger generator.
 

Sbusmech

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Texas
Yikes! I've thinking about a back up generator for some time. I do hate the high pressure sales tactics though. I think I think I'll get a good generator at Harbor Freight then have an electrician get me a plug in to my power.
 
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jade97

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What are you running in a house that you need 115 amps of power?

I have a 7.5kw and it's more than enough.
Heat, few lights, fridges/freezer, well pump... and still plenty left.

I can see around a 12-14kw if you have A/C and "need" it.
So you're saying my 38kw is too large?

All electric house (4t heat pump w/electric back up, electric water heater, well, septic, electric appliances, electric fireplace....)

Not everyone's situations are the same
 

Sumboodie

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So you're saying my 38kw is too large?

All electric house (4t heat pump w/electric back up, electric water heater, well, septic, electric appliances, electric fireplace....)

Not everyone's situations are the same
100 amp service is all we get.
 

My Old Tools

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Hamrick Lake, TX
So you're saying my 38kw is too large?

All electric house (4t heat pump w/electric back up, electric water heater, well, septic, electric appliances, electric fireplace....)

Not everyone's situations are the same
I love my 37kw water cooled. That Mitsubishi 4 cylinder just quietly chugs along.
 

dcg9381

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Austin, TX
Called Generac and they sent one of their local reseller/installer out and he quoted us $15k for the generator and installation. This seems high considering I can buy the generator at Home Depot for $7k. He offered us 5% off if we signed up the day he was here telling us if we did not he might be hard to get in touch with. Sounds like a timeshare racket to me. Any reason not to buy the generator from HD and find a licensed Electrician/Plumber to install since the gas and Transfer box are already installed?
$15k-$20k is the going rate around here. They seem to quote at that across the board. Which is a big ridiculous if you've got the ATS already wired in and propane at the pad.. Crazy.

I did what you did, bought the ATS - had it added during construction. Hardest part was it took 4 people to carry the generator about 30 feet uphill to the pad. Plumber ran a gas line. Total install cost $2k, if that...
 

Sumboodie

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I love my 37kw water cooled. That Mitsubishi 4 cylinder just quietly chugs along.
An oversize gen set isn't good either.

At the shop we had a ~300kw (i may be off,it's been some years) unit we got in trade for $$ owed. Had a 220 Cummins, which is like 12 liter? (I forget now)
It would wet stack just powering the shop. Was fine to run the 5 head planer though. (Cheaper to run the generator than get 3 phase power)
 
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Jackfre

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N CA
I installed my own. When after a couple years I wanted a trained guy to look it over he hit me pretty good, but it was worth it. I saved a lot up front and developed the trained tech where needed.
 

astrohip

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Mar 7, 2015
Messages
340
Location
Brenham TX
What are you running in a house that you need 115 amps of power?

I have a 7.5kw and it's more than enough.
Heat, few lights, fridges/freezer, well pump... and still plenty left.

I can see around a 12-14kw if you have A/C and "need" it.
I'm glad a 7.5 works for you. For many of us, it won't. Heck, my 2HP well pump would use 1/3 of that before anything else gets to say hello.

A/C if we "need" it? When you lose power in TX in the summer, you "need" it. We have four AC units, but only run two if we lose power. Between the AC and pump, your 7.5 is one and done.

Lose power for an hour or two, sure you can get by. I've lost power multiple times, the longest was 8 days after a tropical storm. Unless you want to live like a hermit, you'll need the washer/dryer, well pump, AC, refr, oven, etc.

I have friends who can struggle by with a portable gen, and I'm happy it works for them. I have two 200 amp panels, and one 100 amp panel. I need a standby generator.
 

dcg9381

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I'm glad a 7.5 works for you. For many of us, it won't. Heck, my 2HP well pump would use 1/3 of that before anything else gets to say hello.
And there is start surge.
But it's a fair point. I've got a 20kW generator... I'm sure if I ran a load calc, it'd say that I'm under-provisioned. But reality is that my annual peak power pull for this year is 15kW - which is across the house and shop... At $7k not much price difference between 20k and 28k though, so maybe that's the right answer.

ATS makes everything way easier... Worth it.
 

PoorUB

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Fargo, ND
I used to sell and install Generac.

I thought about putting one on my house, then decided the ever ten years longer power outage didn't justify it. I have a 7,000 watt portable that works just fine for my situation.
We have been in this house for 35 years and have had one power outage that lasted two days. We have had very few last more than a couple hours. No sump pump to deal with. Really the 7,000 watt is too large and I would prefer a smaller unit, about half the size. Easier to move around.

As for the OP, make certain the plumber or electrician read the manual, and have a Generac tech for startup for warranty. Pretty sure a trained tech is required for startup. The gas hook up can be tricky, but it should be all in the manual. They take a huge amount of gas and many installers run to small of pipe.
 
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Bert_

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I've got a little 4kw portable. Can't run the stove or dryer, can still cook with other appliances and even run the a/c.
 

Sumboodie

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AK
I'm glad a 7.5 works for you. For many of us, it won't. Heck, my 2HP well pump would use 1/3 of that before anything else gets to say hello.

A/C if we "need" it? When you lose power in TX in the summer, you "need" it. We have four AC units, but only run two if we lose power. Between the AC and pump, your 7.5 is one and done.

Lose power for an hour or two, sure you can get by. I've lost power multiple times, the longest was 8 days after a tropical storm. Unless you want to live like a hermit, you'll need the washer/dryer, well pump, AC, refr, oven, etc.

I have friends who can struggle by with a portable gen, and I'm happy it works for them. I have two 200 amp panels, and one 100 amp panel. I need a standby generator.
I lived in Houston, San Antonio and Witchia Falls. No A/C
Same in Idaho where normal summers temps are in the 100s.

Wasn't fun, but I didn't die (least I think i didn't). I get sweaty at above 65* so not like the southerners that act like 10* is deathly frigid and 90* is comfy haha.

Even if a/c is "required", that's what, 30 amps?

You all buying 10k, 20k... $30,000 gen sets for the maybe once a year few days (if that) power outage are for sure not anywhere near my tax bracket!
And don't even start about the power outage for 2 weeks back in 1996 or whatever like it happens every few months.
I have under $500 in mine.

Point I was making is size it properly. There's no need to expect every power draw will be on while on emergency power.

Even my "tiny" (normal size) 7500 watt needed a gas meter upsize to handle.

35,000 watts would be commercial gas service, which is expensive. The monthly feed is more and the rates are higher.

Do whatever you want, not my money, but it was asked.
 
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racecougar

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Missouri
Even if a/c is "required", that's what, 30 amps?
Depends on the unit of course. Mine is on a 50A 240V breaker. Heat is on two 60A 240V breakers. Needless to say, I don't power up the heat pump when I'm running my portable generator, though I can power up much of the rest of the house.
 

dcg9381

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I lived in Houston, San Antonio and Witchia Falls. No A/C
Even if a/c is "required", that's what, 30 amps?
No AC in Texas? Glad we don't kink shame...

There is a big AC in-rush, so running current and starting current may be different things. Could always do soft-starts.

And I've got a "portable" generator with an interlock for the shop, I ain't throwing stones. Depends on what your goal is. The OP has already installed the ATS and has a gas line, so it's not going to cost a fortune (despite his quotes).

Biggest power draw typical on TX homes is actually for our emergency heat strips since builders typically install heat pumps that don't work worth a darn in really cold weather... You know for the 4 days every few years that it gets really cold in TX.

As it's hot as hell here, you never know how LONG the power will be down - could be 2 minutes, 2 hours, 2 days... The auto-start and ATS system prevents a bunch of manual labor in the 100 degree heat. There is some value in that.
 

Bert_

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My parents have an heat pump. Got a 25kw pto generator, but that would burn to much diesel to run continuously though.

They have a little propane wall heater for power outages. Big enough to keep that half of the house warm. Don't think they have ever used it but it's there.
 

Snapped-off

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I lived in Houston, San Antonio and Witchia Falls. No A/C
Same in Idaho where normal summers temps are in the 100s.

Wasn't fun, but I didn't die (least I think i didn't). I get sweaty at above 65* so not like the southerners that act like 10* is deathly frigid and 90* is comfy haha.

Even if a/c is "required", that's what, 30 amps?

You all buying 10k, 20k... $30,000 gen sets for the maybe once a year few days (if that) power outage are for sure not anywhere near my tax bracket!
And don't even start about the power outage for 2 weeks back in 1996 or whatever like it happens every few months.
I have under $500 in mine.

Point I was making is size it properly. There's no need to expect every power draw will be on while on emergency power.

Even my "tiny" (normal size) 7500 watt needed a gas meter upsize to handle.

35,000 watts would be commercial gas service, which is expensive. The monthly feed is more and the rates are higher.

Do whatever you want, not my money, but it was asked.
Mine was just out for 5 days a few weeks ago. Buddy a few towns over was down for 12 days.

Mines a 16kw natural gas, but it came with the house. Both neighbors lost all the food in their fridges and freezers, as their portable gens were only running for the well and sump pumps. I would've offered up my spare fridge and deep freeze if I knew. They both know for the next outage though.

I'd still go whole house though if I ever move, 16-20kw is plenty for me.
 

Snapped-off

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Indiana
Looking at a Generac 28kw air cooled generator. We had the generac 200amp transfer switch and propane port installed when we built the house. Called Generac and they sent one of their local reseller/installer out and he quoted us $15k for the generator and installation. This seems high considering I can buy the generator at Home Depot for $7k. He offered us 5% off if we signed up the day he was here telling us if we did not he might be hard to get in touch with. Sounds like a timeshare racket to me. Any reason not to buy the generator from HD and find a licensed Electrician/Plumber to install since the gas and Transfer box are already installed?
My mom was just quoted $12k for a 24kw/200A ATS installed.

Can get the gen and ATS for $7k at Menards.
 

Worsedog

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Central FL
An oversize gen set isn't good either.

At the shop we had a ~300kw (i may be off,it's been some years) unit we got in trade for $$ owed. Had a 220 Cummins, which is like 12 liter? (I forget now)
It would wet stack just powering the shop. Was fine to run the 5 head planer though. (Cheaper to run the generator than get 3 phase power)
Many places require full capacity if on an ATS, or some kind of load shedding.

Never seen a gas generator wet stack, but I've not seen everything.
 

dcg9381

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Austin, TX
My parents have an heat pump. Got a 25kw pto generator, but that would burn to much diesel to run continuously though.
Do they have a means to wire in 25kW and by-pass the grid?
They have a little propane wall heater for power outages. Big enough to keep that half of the house warm. Don't think they have ever used it but it's there.
Honestly, this is what I do here in TX when it's really cold. Our heat pumps are terribly inefficient in cold weather and the emergency heat that kicks in below freezing result in bigger bills that summer. I branched two drops for the tankless water heater and the a gas stove (which is induction). With one 30k unit on the lower floors, it heats the whole house... I literally switch to ventless propane for the 2-7 days in the winter when it's really cold. I get some moisture collection on windows, so it's not a good long term solution, but economically for a $200 ventless heater and the option to be "out of power" for long term, it's my backup...
 

phred

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Apr 23, 2009
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NC
That price doesn’t seem unreasonable however make sure you research the genset you choose and make sure they have updated the specs. Myself and my neighbor had 20kw genset installed in the past couple of years. Mine is a cummins and his is a generac. Both wouldn’t run and it took the cummins and generac techs a couple weeks to sort it out. For some odd reason both manufacturers changed the gas pressure requirements for the engines and didn’t change the pressure regulators listed in the specs. Very frustrating and odd that for both of us to have the same issues.
 

My Old Tools

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I lived in Houston, San Antonio and Witchia Falls. No A/C
Same in Idaho where normal summers temps are in the 100s.

Wasn't fun, but I didn't die (least I think i didn't). I get sweaty at above 65* so not like the southerners that act like 10* is deathly frigid and 90* is comfy haha.

Even if a/c is "required", that's what, 30 amps?

You all buying 10k, 20k... $30,000 gen sets for the maybe once a year few days (if that) power outage are for sure not anywhere near my tax bracket!
And don't even start about the power outage for 2 weeks back in 1996 or whatever like it happens every few months.
I have under $500 in mine.

Point I was making is size it properly. There's no need to expect every power draw will be on while on emergency power.

Even my "tiny" (normal size) 7500 watt needed a gas meter upsize to handle.

35,000 watts would be commercial gas service, which is expensive. The monthly feed is more and the rates are higher.

Do whatever you want, not my money, but it was asked.
No, 37kw doesn't require commercial gas service. Mine runs great on a propane tank and a 5/8" gas line. Oversized doesn't mean you're pulling full power all the time. Most of the time its just loafing along and sipping fuel. Water cools are just more efficient. And yes, HVAC is required. I run a geothermal heatpump system year around. When you have an ice storm and every power line for 100 miles goes down, it can take days to weeks to get back up. A hurricane in the gulf can take out power over hundreds of miles and take weeks to restore, meanwhile Houston has evacuated and every motel for 200 miles is full. It doesn't happen every few months, but its often enough that having the generator keeps you from losing freezers full of food and having every water line freeze and break in the winter.
 

Sumboodie

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AK
No, 37kw doesn't require commercial gas service. Mine runs great on a propane tank and a 5/8" gas line. Oversized doesn't mean you're pulling full power all the time. Most of the time its just loafing along and sipping fuel. Water cools are just more efficient. And yes, HVAC is required. I run a geothermal heatpump system year around. When you have an ice storm and every power line for 100 miles goes down, it can take days to weeks to get back up. A hurricane in the gulf can take out power over hundreds of miles and take weeks to restore, meanwhile Houston has evacuated and every motel for 200 miles is full. It doesn't happen every few months, but its often enough that having the generator keeps you from losing freezers full of food and having every water line freeze and break in the winter.
It does here.

Running mine and heat required a different regulator almost the larger gas meter, which puts it to commercial service. Or a seperate feed/meter JUST to the gen set, which is ~$25 a month just to have.

A 37kw gen set is roughly equal to running a 550,000 BTU furnace. That would need a 2" feed, or the pressure kicked up a fair bit.
Std service here is good to around 300k btu.

Point being, there maybe alot of added costs, if even possible to put in a huge Gen set.
Propane isn't practical here, may as well go diesel at that point, it's near half the price and far easier to get.
 
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PoorUB

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Fargo, ND
A 37kw gen set is roughly equal to running a 550,000 BTU furnace. That would need a 2" feed, or the pressure kicked up a fair bit.
Std service here is good to around 300k btu.
Where I live the gas supplier doesn't twitch until the residence gets somewhere over 1mil BTU. Seems to me we ran into a house that the total load was 1.7mil and the largest meter the utility had for residential was 1.5mil. Over that is was the huge rotary commercial meter. We have added generators to many houses that bumped them well over the 550,000 you mention. No 2" pipe needed either. 3/4
at 2 PSI will do it easily.

I forget what the utility feeds from the street, but I think it was 3/4" and a decent PSI, maybe 40 PSI? But I forget. Either way we have never had a home where the supply from the street wasn't large enough. After the meter all new construction is 2 PSI and older homes can be bumped up to 2 PSI after a pressure test and of course adding regulators.

3/4" pipe at 2 PSI at 100 feet will supply roughly 1mil BTU so rarely is there a need to larger pipe sizes in residential. There are a lot of homes in the area piped completely with 1/2" CSST.
 

Sumboodie

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It's .25psi here. To step up to 2psi requires a new regulator and $$.

And obviously I realize "here" doesn't mean everywhere.

It's just something to consider when sizing and pricing a unit.
 
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