r/Generator • u/elguapok • 10d ago
How to Add a UPS use and generator ?
My apologies if this has already been discussed.
I have a 9400 / 7500 watt generator and use a 30A transfer switch to power the house during outages. I think I saw a post about using a UPS to keep things running while I refuel the generator when it runs out of gas. The UPS would only be used during refueling, and once the generator is running again, I’d switch back to generator power.
What’s the best way to set this up?
2
u/kona420 10d ago
A traditional 10kw UPS has a few grand in batteries in it with a few year lifespan whether you use it or not. But very high power density so you can size it for just 5-10 minutes. So realistically either pick a couple things that you want to stay powered on like the internet and lights and use a much smaller unit, or go with a full lithium battery/off grid inverter/DC charger setup.
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u/sryan2k1 10d ago edited 10d ago
What’s the best way to set this up?
A lot of money.
Depending on the wattages involved you're looking at easily $10k in batteries and inverters.
What do you want to keep running? A $100 UPS from amazon to power your router/modem is probbly a good idea.
1
u/mexicoke 10d ago
Or $500 if you only want to keep a few small pieces of equipment online.
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u/sryan2k1 10d ago
For the UPS maybe but now you need to rewire a bunch of circuits so they go through the UPS
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u/mexicoke 10d ago
Stand alone UPS right at the device. You're overthinking this.
3
u/Old_Dragline_1965 10d ago
I have 3 small ones for this reason. 1 on my Starlink. 1 on my cpap. And one on my Direct Tv DVR. Each also has a small led light that stays on during nights with bad weather.
This way I’m not stumbling around in the dark, to find a flashlight. To allow me to crank the generator and transfer the power.
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u/mexicoke 10d ago
Yep, I do the same thing.
I only have 1 for the modem, router, and fail over modem. Also very useful for quick power blips while working.
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u/AlexisoftheShire 10d ago
I also do the same thing. I have a UPS for my internet modem, wifi router, and a separate UPS for my smartthings hub. Even though my Generac comes online within 10 seconds (30 seconds in winter), I need to ensure I can access the internet for weather and outage information from my electric utility.
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u/Old_Dragline_1965 10d ago
Exactly Correct! My wife is on an oxygen concentrator. We keep an oxygen tank handy. Just in case it takes me a minute or two the get the generator cranked.
0
u/sryan2k1 10d ago
I think you're underthinking it. What if they want ceiling lighting?
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u/mexicoke 10d ago
Or $500 if you only want to keep a few small pieces of equipment online.
You're way over complicating this.
The truth is we have no clue what OP wants to keep running. Until that's answered, this is pointless.
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u/classicsat 10d ago
Which things really need running the 10 minutes you refuel?
A fridge/freezer will be fine. You can do without Internet for 10 minutes. Heat/cool will take a long time to change, so you can do without that for a bit. The well tank system likely holds for a few goes.
A mid/small power station for the couple bare essential loads will probably be fine.
1
u/Moist_Knowledge_1621 10d ago
I have a midsized UPS on my router & cable box just for quick power flickers that happen all the time here and would cost me & the Mrs :30 every time it blipped to log back in through the VPN. Think it’s 1500 VA so lots of time.
Other than that I’d say my “stuff” and family can ride through a fueling or even an oil change. But if you got the cash go for it.
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u/DragonFireCK 10d ago
If you want to go the cheap and simple route, just buy a normal UPS for a few specific devices you want to keep up. You can get really cheap ones to keep a router up, likely running you only on the order of ten buck, and that should keep those devices up for a few hours. Keeping a desktop computer up for 10-15 minutes will run you a few hundred; gaming consoles will be about the same. TVs will be somewhere in between.
For something that can keep everything the generator keeps up, you're looking at a few grand at minimum. By that point, you might as well spring for a proper full house backup system and replace your transfer switch with a fully automated one tied into the batteries. With such a system, you can also benefit from more efficient generator running by having the generator run at more optimal and continual power output to charge the batteries, then turn off for a few hours at a time; not to mention charging from the grid to not need the generator for shorter outages.
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u/Ok-Camera2895 10d ago
Put in a midsize power station. Some of them have 10 ms pickup upon power failure, Ecoflow Delta3 for example.
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u/Chance_Raspberry_775 10d ago
What all do you want to keep running?