HELP with portable generator and Central Air

[Dave Lehnert]

Need a little help with portable generator and Central Air.

Going through the process of calculating what size portable generator I need. Know the central air is a BIG draw of power from the generator. I cant seem to translate what size unit I have and how big a generator I need to just run the central air.

I have a Carrier brand unit and the model number is 24ACB336A300. I believe the 336 is the number I need but confused with tonnage number and how to convert that into what size generator I need just for that. Example 2500KW vs 5000KW or bigger.

My thinking. Where I live the electric does not go out too often, but when it does, it is often back on in an hour or two. For this reason I dont want to drop a huge amount of $$$ on a generator that may never get used but want to be prepared. Im ok with having to turn off everything to kick the Central Air on for a few to cool the house off. So I want a generator that big enough to run the air but not so big that it runs everything.

[Kev Williams]

assuming yours is the 24-30 series, specs say 13.5 compressor and .75 fan amps, so 14.25 amps, which is roughly 3200 watts at 220 volts... locked rotor amps is 58.3, but I'm not sure how that translates to starting amps-

... an 8000w unit might be okay for your needs-- ?

[Jim Becker]

It's the starting amps that can kill you with an HVAC system. Even the large, whole house units have to account for that in how they behave...some even monitor the HVAC system startup with a small module that gets installed at the compressor.

[Larry Frank]

I thought about using a portable generator but decided against it due to concern about the electronics. I eventually got a Generac whole house generator.

[Dave Lehnert]

I thought about using a portable generator but decided against it due to concern about the electronics. I eventually got a Generac whole house generator.


They now make portable open frame inverter generators with a very low THD. 6250/500KW for about $700

[Bruce Wrenn]

Look at an Easy Start Kit for your AC. Lots of You tubes out there. Reduces starting current to a level where a 5KW generator can run your condensing unit. If you don't live in a HOA community, a 5000-6000 BTU window unit is cheaper than an Easy Start kit.

[bill godber]

No help with the size of generator but have a look at the propane fired models. A gas generator needs to be run regularly to prevent the gas from jelling, the propane not so much.

[Bill Dufour]

Do you have a smart meter on the house. My old smart meter was dumb with no useful information at all. We moved and this smart meter will show watts being used. It shifts the display every 15 seconds or so from total KWH. to instantaneous watts being drawn.It does not show voltage like my mom's did.
I think the local utility thinks we are too dumb for that information.
Bill D

[Tom Bender]

How will you connect the generator to the A/C? At my house the furnace fan and the condenser are on different circuits and different voltages. A whole house transfer switch would make the most sense, but not an automatic one due to the need to reduce load first by switching off some circuits. That would allow running some other things when the A/C is not on, like the sump pump, the heat, lights, TV, etc. You are feeling the heat right now but in a few days you will feel the cold.

For years I waffled on a good approach and finally bit the bullet and installed a Generac. Have not regretted it.