Home AC on Generator-WORKS!

[capkmo]

Are there any options to run my home air conditioner on the 7.2kw generator?
I bought a SoftStartHome today and it almost gets the AC started before the breaker trips on the truck.
I started looking at a Hard Start Kit (basically a large capacitor) for the AC unit as well but I’m not sure it’ll work
Any other options?
AC model if helpful: 4TTR3043A1000NA

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[fwunder]

Looks like you are not alone:

 

[adyaro77]

So what you're dealing with is startup surge as you may know. For over 20 years I have been installing home generators. Startup surge is extremely important. Even with a soft start. If you don't have enough startup surge you're just damaging the generator. I have installed generators sized properly. Years later as the capacitor goes bad in the condenser, the customer started noticing the generator wouldn't start with the AC on. So if you ever purchased a generator before... you'll see running watts and surge Watts. So before I install a generator I do what is called a load study. Up until electrical vehicle chargers A/C's were the biggest issue. For example some people will purchase a smaller generator and then put the AC condenser on what's called load shed. These are devices that don't let the AC start when the generator is running. So you need to figure out what your surge watts are. The easiest way to figure out the amp/watt spike from the A/C is with an amp probe. Have someone turn on the AC while you hold the amp probe. With some simple electrical math you can figure out the starting watts.

I think you're going to be shocked on how high it is. Also obviously having a more efficient air conditioner is extremely important. I have done generator installs where we upgrade the air conditioner as well just to drop start up watts. Usually they need a new one anyways.... Not upselling.

 

[capkmo]

Thank you, it doesn’t sound like there’s any easy solution on there that I haven’t tried yet but glad to see it’s not just me

 

[capkmo]

So what you're dealing with is startup surge as you may know. For over 20 years I have been installing home generators. Startup surge is extremely important. Even with a soft start. If you don't have enough startup surge you're just damaging the generator. I have installed generators sized properly. Years later as the capacitor goes bad in the condenser, the customer started noticing the generator wouldn't start with the AC on. So if you ever purchased a generator before... you'll see running watts and surge Watts. So before I install a generator I do what is called a load study. Up until electrical vehicle chargers A/C's were the biggest issue. For example some people will purchase a smaller generator and then put the AC condenser on what's called load shed. These are devices that don't let the AC start when the generator is running. So you need to figure out what your surge watts are. The easiest way to figure out the amp/watt spike from the A/C is with an amp probe. Have someone turn on the AC while you hold the amp probe. With some simple electrical math you can figure out the starting watts.

I think you're going to be shocked on how high it is. Also obviously having a more efficient air conditioner is extremely important. I have done generator installs where we upgrade the air conditioner as well just to drop start up watts. Usually they need a new one anyways.... Not upselling.

I was really hopeful that SoftStartHome would at least allow it to kick on once. I’ll have to keep looking for other options or just get some portable units for emergency use

 

[adyaro77]

I was really hopeful that SoftStartHome would at least allow it to kick on once. I’ll have to keep looking for other options or just get some portable units for emergency use

The smallest generator that I personally ever installed that ran a customer's air conditioner was 10K. If I remember right It had a minimum circuit ampacity of approximately 15 amps. There's a lot of different contributing factors, but your A/C startup is probably right around 1200 watts more at a minimum than it's running watts.

Definitely pay attention to the surge Watts.

 

[capkmo]

The smallest generator that I personally ever installed that ran a customer's air conditioner was 10K. If I remember right It had a minimum circuit ampacity of approximately 15 amps. There's a lot of different contributing factors, but your A/C startup is probably right around 1200 watts more at a minimum than it's running watts.

Definitely pay attention to the surge Watts.

This is extremely helpful, thank you! Sounds like the most straight forward answer is that I won’t be able to run the AC using the powerboost- which is fine since everything else in the house runs great on the truck

 

[adyaro77]

This is extremely helpful, thank you! Sounds like the most straight forward answer is that I won’t be able to run the AC using the powerboost- which is fine since everything else in the house runs great on the truck

My pleasure. I attached just for an example of a 9,500 watt Generac generator that shows its surge/starting Watts. 3000 starting watts is fantastic by the way.

 

[FaaWrenchBndr]

I was really hopeful that SoftStartHome would at least allow it to kick on once. I’ll have to keep looking for other options or just get some portable units for emergency use

Yeah, we have everything set up to wear. We will just utilize one room, kitchen and the bathroom.
If need be the window unit we have will suffice

 

[Powerboost_Law]

I know better than to have the A/C on when I get the equipment to hook my Powerboost to my house, just as it is now the lights give a flicker when my A/C starts, my unit is a Bryant it is 25 years old however works fabulous, I have a 200 amp panel and my house is 5 bedroom 2,200 Sq/ft. I'm a little worried about the truck being able to handle the well pump, I hooked a well pump that had a control box to the truck, it had a capacitor in it and it just tripped the truck breaker, yet when hooked to the house once it worked just fine. we'll see how this plays out this summer when I get all the equipment to hook my truck up.

 

[Phil823]

100% install a soft start! Better for condenser motor and allows you to run your house of a far smaller generator in general.

I setup a westing house 11500trifuel on NG with a remote start button that can run the whole house is a matter of seconds. All for about 2k$. Wayyy cheaper than a generac.

 

[capkmo]

BIG UPDATE: I got the 3.5 Ton Trane AC to run on the PowerBoost!!
Huge shoutout to Micro-Air EasyStart which is what made this happen and took 15 minutes to hookup (to note, EasyStartHome did not work and they blamed the truck)
Photos taken are with only the A/C running, all other breakers off but obviously room to run more

3.5 Ton A/C unit: 4TTR3043A1000NA
EasyStart: https://www.microair.net/products/easystart-flex-home-ac-soft-starter

 

[tsigwing]

I have the same easy start on my 3.5ton home unit, but my start up amps are over 30.

 

[m_bt54]

I have the same easy start on my 3.5ton home unit, but my start up amps are over 30.

Same

 

[Gros Ventre]

A good rule of thumb for starting surge is 2 1/2 times running current.

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