Generator Transfer Switch

Freezer, Frig, lights, HVAC circulating pumps, AC units. 2nd frig. It's easy to exceed the capacity of a 6kw unit.

I had a 6kw standby generac. When the small motor in it died, I changed to a whole-house 20kw unit.
Forced air heat, well, two freezers, lights, hot tub… in dark and cold Alaska winter. Never any problem with my Honda 6kw. I’ll test my TX house’s AC with the generator next week. According to the spec sheet I shouldn’t have any issue with running AC and the rest of the house on 6kw.
 
We went through, and figure with the AC or the hot tub running (don't need to have both since, if it's blazing hot that we need the A/C the tub won't be in use), plus the electric stove, plus the electric dryer, the fridges, etc, we would still be fine with everything else in the house running and that was at 13k. and if I needed to run some items in the shop, I'd still be fine.

Size matters, 13kw sounds small for an ac unless it's a small ac or maybe if it's lightly loaded. A 4 ton unit is supposed to have about 17 kw, mostly to get it started.
 
We went through, and figure with the AC or the hot tub running (don't need to have both since, if it's blazing hot that we need the A/C the tub won't be in use), plus the electric stove, plus the electric dryer, the fridges, etc, we would still be fine with everything else in the house running and that was at 13k. and if I needed to run some items in the shop, I'd still be fine.
What kills mine is not the running load, but the starting draw when the old AC kicks in.
 
Time to update your AC. New multi stage compressors and variable speed fans make a huge difference in comfort and energy use.
 
What kills mine is not the running load, but the starting draw when the old AC kicks in.

Haven't had that issue. Power went out this week. A/C kicked on just fine. A/C unit is only 2-3 years old. The only 'problem' was the kids complaining that they got booted from whatever online games they were playing waiting for the standby to kick on.
 
Someone mentioned soft start addition.

You hard starters may want to look into that, might help.
 
The first time I put in a generator, the price difference between a 6000 watt generator and a 20,000+ watt generator was quite a bit.

The price of a whole-house generator has dropped quite a bit in recent years. And, interestly, the natural gas usage of a new 20000w generator is actually similar to my old 6000w generator.
 
The first time I put in a generator, the price difference between a 6000 watt generator and a 20,000+ watt generator was quite a bit.

The price of a whole-house generator has dropped quite a bit in recent years. And, interestly, the natural gas usage of a new 20000w generator is actually similar to my old 6000w generator.
Depends on the type of generator. A 24K watt Generac is about $6K installed, often including the auto-transfer switch ($700). A Harbor Freight Inverter generator at 9.5K watts is $2,500. So, the price per watt isn't wildly different. The 22.5K (15K continuous) Generac portable that I have currently is about $3K new, but it's not an inverter generator and as I mentioned, is LOUD. Kubota makes some "Lowboy" portable diesel generators that run much quieter, but they are $$$$ (like $8K for 10K watts).
 
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Depends on the type of generator. A 24K watt Generac is about $6K installed, often including the auto-transfer switch ($700). A Harbor Freight Inverter generator at 9.5K watts is $2,500. So, the price per watt isn't wildly different. The 17.5K (15K continuous) Generac portable that I have currently is about $3K new, but it's not an inverter generator and as I mentioned, is LOUD. Kubota makes some "Lowboy" portable diesel generators that run much quieter, but they are $$$$ (like $8K for 10K watts).

24 years ago, a whole-house standby generator would have been over $10,000 installed... which is the reason I went with a smaller standby generator 24 years ago.
 
My gen is rated 67 db at 23 feet. You can hear it, but certainly not like my old 5000 watt Briggs and Stratton gen
 
A Generac 24.5 kw standby generator with a 200 amp switch is listing for $6,400 today, then you have to install it.
 
My gen is rated 67 db at 23 feet. You can hear it, but certainly not like my old 5000 watt Briggs and Stratton gen

The GP15000 model specs don't list it, and on 3rd party websites is states "not measured by manufacturer" lol. That pretty much tells me they don't really want that info out there. It was loud enough that I had to walk behind my FIL's truck in order to talk to him while it was running.
 
I have a Northern Lights 6kw diesel at the cabin. We’re mostly solar powered there but when the inverter needs to charge batteries, it’s rated 120a so needs a good genset. The reason diesel is quieter than the 4kw gas Yamaha that’s next to it is diesel gensets run at 1800 rpm and non-inverter gas gensets run at 3600 rpm. My home 6kw inverter Honda (10kw surge) is the quietest unit I own, not counting my little portables. I’ll get a new Honda 7 kw inverter genset for the new TX house eventually. I’ll wear this 6 kw Generac out first. We needed it for construction so already own it. Now to see how reliable our grid power is. My standby connection is 2’ from my overhead door so a rolling generator is simple to use when needed. Wife would be ****ed to see a permanent standby genset cabinet sitting there. She was reluctant to build outside of natural gas service until I convinced her we could bury the propane tank.
 
The GP15000 model specs don't list it, and on 3rd party websites is states "not measured by manufacturer" lol. That pretty much tells me they don't really want that info out there. It was loud enough that I had to walk behind my FIL's truck in order to talk to him while it was running.

Yeah, that's a portable, those are earsplitting. No weight concerns on the standbys, big mufflers and sound deadening cabinets.
 
Thought I'd weigh in here. Here's a couple of pictures of my power setup...

53006175274_dc1646cbae_4k.jpg

53006175269_a1f87c9ef2_4k.jpg


The top picture shows the two solar inverters, a small subpanel to combine the two, and the solar disconnect (you can see the other end of the generator at the far right).

The next picture shows the 80KW Generac liquid-cooled generator, the electic meter, my service disconnect, the Geenrac automatic transfer switch. From there it goes to a large panel in the hangar which in turn feeds seven subpanels around the house.
 
Thought I'd weigh in here. Here's a couple of pictures of my power setup...

53006175274_dc1646cbae_4k.jpg

53006175269_a1f87c9ef2_4k.jpg


The top picture shows the two solar inverters, a small subpanel to combine the two, and the solar disconnect (you can see the other end of the generator at the far right).

The next picture shows the 80KW Generac liquid-cooled generator, the electic meter, my service disconnect, the Geenrac automatic transfer switch. From there it goes to a large panel in the hangar which in turn feeds seven subpanels around the house.
That is a heck of a system, lol. I'm surprised that size gas line is enough to feed an 80kw generator (assuming the line in the first pic was the feed line coming off of the regulator).
 
22kW whole house Generac was $6750 installed 9 years ago for me. Would have gone 24kW if it was available as we had a hot tub at the time and were looking at GeoThermal w/ electric heat strips for the backup. Paid for itself the first power outage. Don't worry as much about basement flooding anymore.
If you're running a whole house Generac check out GitHub - jgyates/genmon: Generac (and other models) Generator Monitoring using a Raspberry Pi and WiFi instead of paying for Generac's Mobile Link service. Handy to know when we're on generator power when not home.
With some UPS backups for the computers/modems/routers you won't skip a beat when you lose power and the gen automatically kicks on 10-15 seconds later.
 
22kW whole house Generac was $6750 installed 9 years ago for me. Would have gone 24kW if it was available as we had a hot tub at the time and were looking at GeoThermal w/ electric heat strips for the backup. Paid for itself the first power outage. Don't worry as much about basement flooding anymore.
If you're running a whole house Generac check out GitHub - jgyates/genmon: Generac (and other models) Generator Monitoring using a Raspberry Pi and WiFi instead of paying for Generac's Mobile Link service. Handy to know when we're on generator power when not home.
With some UPS backups for the computers/modems/routers you won't skip a beat when you lose power and the gen automatically kicks on 10-15 seconds later.
Agreed, a few UPS units make quick power flashes a non-event as well.
 
22kW whole house Generac was $6750 installed 9 years ago for me. Would have gone 24kW if it was available as we had a hot tub at the time and were looking at GeoThermal w/ electric heat strips for the backup. Paid for itself the first power outage. Don't worry as much about basement flooding anymore.
If you're running a whole house Generac check out GitHub - jgyates/genmon: Generac (and other models) Generator Monitoring using a Raspberry Pi and WiFi instead of paying for Generac's Mobile Link service. Handy to know when we're on generator power when not home.
With some UPS backups for the computers/modems/routers you won't skip a beat when you lose power and the gen automatically kicks on 10-15 seconds later.

We have geothermal HVAC (ground source), but no backup heat. The systems are sized enough that they keep up with out coldest days.
I have genmon for sure. Note you can only use this if your generator firmware hasn't been updated to make the modbus port proprietary.
 
Nah. I have friends with remote lodges that power guest buildings, dining halls, guide shacks, boat houses, meat sheds with lots of freezers, cater to 30+ people, and run their operations on 20kw generators as primary power. They have power to spare. Of course they have to fly fuel in so they can’t afford to be wasteful, but they can’t run short, either.
 
I can run the whole house on my 5500W Generac. Propane for heat, hot water, stove, and dryer, no AC, so the biggest loads are the well pump, laundry machines, and fridge.
 
With some UPS backups for the computers/modems/routers you won't skip a beat when you lose power and the gen automatically kicks on 10-15 seconds later.
My computers, modem, router are all on battery backups. I even have a lamp in our living room on battery back up. No searching for a flashlight in the dark.
 
So when the power is out, what are you guys planning on running that you need 24KW of backup power? If I turn EVERYTHING on in my house and workshop, I won't come close to hitting that number.
At my last house, we had a 38kw water-cooled Generac. I wanted automatic transfer and all circuits. For such a setup, code here requires capacity off 80% of connected load. Generac makes automatic load-shed modules, which we put on circuits we were really unlikely to need, but that's what we were left with.

On the current house we just have the inlet for a portable generator and the plate that prevents the main and inlet breakers from being on simultaneously. Works great, but entirely manual and will only run the small ac upstairs, fridge, and some lights.
 
At my last house, we had a 38kw water-cooled Generac. I wanted automatic transfer and all circuits. For such a setup, code here requires capacity off 80% of connected load. Generac makes automatic load-shed modules, which we put on circuits we were really unlikely to need, but that's what we were left with.

On the current house we just have the inlet for a portable generator and the plate that prevents the main and inlet breakers from being on simultaneously. Works great, but entirely manual and will only run the small ac upstairs, fridge, and some lights.

Yeah, from my brief research on the transfer switches, they are all supposed to be rated for that 80-percent connected load. I'm sure that's probably to adhere to UL-code standards across the nation. We intend on being in the current home for about 10 more years (basically to get the kids through high school). The next home will likely be wired with the automatic transfer gear and whole-house backup generator. For this exercise I'd rather have the flexibility to use a portable generator and just select the circuits I want to run (or am able to run given the generator capacity).
 
Yeah, from my brief research on the transfer switches, they are all supposed to be rated for that 80-percent connected load. I'm sure that's probably to adhere to UL-code standards across the nation. We intend on being in the current home for about 10 more years (basically to get the kids through high school). The next home will likely be wired with the automatic transfer gear and whole-house backup generator. For this exercise I'd rather have the flexibility to use a portable generator and just select the circuits I want to run (or am able to run given the generator capacity).
This is what I have now:

https://www.homedepot.com/p/Reliance-Controls-30-Amp-Power-Inlet-Box-PB30/202213702

https://a.co/d/9IzPVbZ

Easy to wire up if you're comfortable working in the panel. The input breaker has to be at the top, so you might need to move a breaker that's there. Also wouldn't be expensive to have installed.
 
In my neck of the woods they mandate metal conduit be used throughout and that's the ground.

Found the guy from the Chicago area!

Yup.

The local unions chose conduit, pre-fab housing bans, and lead pipe mandates as their hills to die on, keeping them codified in an attempt to preserve their jobs and union pay.

By then (1986) every other major city in the nation had banned lead pipes and Ballanco’s engineering organization was urging Chicago to adopt a model city code that excluded lead as well.

But the plumbers’ union stood its ground and opposed the measure, and thus it failed to win approval from the city’s aldermen.

“Lead [pipes] have proven over a long time to do the job they were designed to do,” Jim McCarthy, the union’s business manager, told the Chicago Tribune at the time. “I’m hard-pressed to understand why people are talking about lead poisoning. We’ve had lead pipe in the water system here for 100 years.”

...until the federal government banned lead pipes in 1986, Chicago continued to install them. The city’s long delay in banning the pipes is why Chicago has more lead pipes than any other city in the nation today.

“There’s still a lot of lead in Chicago,”


https://hocn.org/profiting-from-poison-how-the-us-lead-industry-knowingly-created-a-water-crisis/
 
I wanted automatic transfer and all circuits. For such a setup, code here requires capacity off 80% of connected load. .
I seriously doubt that. I hear this nonsense all the time, but the NEC doesn't say that. What the NEC says is that for optional standby systems (which your home generator is), it must be sized at 125% of the expected CONTINUOUS load (that is things expected to run non-stop for three hours or more) plus 100% of the non-continuous load. The code says that if your cutover is automatic, then it has to be sized for whatever the automatic system is going to transfer (obviously, if it's automatic you can't really do otherwise). If you have a manual transfer, it's allowed that you will throw breakers to shed the excess load prior to throwing the switch.
 
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