Generator - A/C

[Texanreloader]

I installed a 50Amp box to hook up my Generator to the house. I have a 4 ton a/c unit w/a 9500/12,500 generator. Will this run the a/c?
Is there more information I can post that will help? I am seeing answers all over the place, something definitive would be great. Thanks.

 

[RPH]

Data plates on both would help answer this. Start up current maybe an issue.

 

[mike93lx]

Without a soft start, I seriously doubt it

 

[MongoTA]

Agree with soft start.
Example:

 

[PoorUB]

I sold and serviced generators for some time. I seriously doubt it will start a 4 ton AC. Plus, don't forget the 3/4HP blower motor in the air handler. You are starting close to 5 HP.

Also consider what else is on for a load too. IMO, you need twice that! A soft start might help.

If you were my customer I would have recommended a 15K just for the AC, then add what ever loads you may have running, Microwave, refrigerator, freezer. 20K easily.

 

[Texanreloader]

Data plates on both would help answer this. Start up current maybe an issue.

 

[mike93lx]

It makes enough power to run it, but not start it.

Soft start will give you the best chance

 

[AA/FC]

According to the data plate, your A/C unit is rated to pull 109 amps on startup.... That is over 26000 watts at 240 volts. Your generator does not have a chance to START that compressor.

I have the MicroAir "Easy Start" on my A/C unit and it works great.

There are other brands of soft starters on the market but the MicroAir is the industry leader and they were the first to make a device that helps A/C units start when operating on generator power. It even has a built-in bluetooth module to connect with your phone to see a bunch of different data about your air conditioner.... and it can upload technical data to MicroAir over your phone's internet connection to help diagnose any problem that you might be having. All other brands are copies of the MicroAir, and none of the others have the bluetooth feature. (that I am aware of, anyway) I have no experience with the other brands, I can't say how well they work, or how much they can lower the inrush amperage draw of your A/C unit.... but I know the MicroAir works excellent. It goes through a 5 startup learning process to get your inrush aperage as low as possible.... I do not beleive any of the other brands do the leaning process.

Also, do not get "easy start" or "soft start" confused with a "hard start" kit. They are not the same. A hard start kit is simply an additional capacitor to give your compressor a harder kick on start-up.... which CAN reduce the life of your compressor. The easy start will slowly ramp up the current and it CAN actually extend the life of your compressor. Hard start kits were invented to install on tired old compressors that are almost dead just to get a few extra years of service (maybe?) out of them before they finally need to be replaced. They are usually used in a worst case scenerio. You wouldn't be doing yourself any favors by adding a hard start kit to a compressor (just to see if it will help your generator start it) that wouldn't need it normally.

Easy start = good. No down sides to using one excpet for initial price.
Hard Start = not good (and it doesn't really do much to start your compressor on generator power)

 

[Rick1953]

Without a soft start, I seriously doubt it

Really My brother in Law who is heating and Cooling and certified electrician . Says Soft starts are a pain and often lead to issues

 

[mike93lx]

Really My brother in Law who is heating and Cooling and certified electrician . Says Soft starts are a pain and often lead to issues

I said nothing about how well they work long term

 

[Rick1953]

I installed a 50Amp box to hook up my Generator to the house. I have a 4 ton a/c unit w/a 9500/12,500 generator. Will this run the a/c?
Is there more information I can post that will help? I am seeing answers all over the place, something definitive would be great. Thanks.

what size home

I said nothing about how well they work long term

He's not going to be able to run a 5 ton unit period . I just looked it up and 2 ton units pull 7000 watts . That's if they are brand New and eco friendly . Central air takes some juice . I bought 11.500 running watts and it satisfies 2 freezers ,refrig, almost all my outlets ,sump, water heater ,furnace etc. But central air ? No way unless you have 20,000 watts plus. Generators were never a real issue in the past . These days storms are intentionally generated . I've lived in the country 30 years . We lost power before once in 25 years . Since 2020 7 times . I live in the Farthest Area West that's possible in Michigan. We get snow, but until recently intense storms were a rarity

 

[mike93lx]

what size home

He's not going to be able to run a 5 ton unit period . I just looked it up and 2 ton units pull 7000 watts . That's if they are brand New and eco friendly . Central air takes some juice . I bought 11.500 running watts and it satisfies 2 freezers ,refrig, almost all my outlets ,sump, water heater ,furnace etc. But central air ? No way unless you have 20,000 watts plus. Generators were never a real issue in the past . These days storms are intentionally generated . I've lived in the country 30 years . We lost power before once in 25 years . Since 2020 7 times . I live in the Farthest Area West that's possible in Michigan. We get snow, but until recently intense storms were a rarity

Shenanigans.

My cheapie 2.5 ton 14 seer units are pulling 2150 watts runnning. 7000? No idea how you came up with that.

My 10 ton pool heat pump plus the 2hp pump only pulls 7900. That little spike is the chlorinator turning on

Here is real data instead of google searches

 

[theoldwizard1]

Agree with soft start.
Example:

Not familiar with that brand, but this is BUYER BEWARE territory !

Some "soft start" A/C addons are not TRUE soft start ! A true soft start LIMITS the amount of current the A/C draws for the first couple hundred msec.

I have the MicroAir "Easy Start" on my A/C unit and it works great.

Well known, highly rated, brand

 

[AA/FC]

Really My brother in Law who is heating and Cooling and certified electrician . Says Soft starts are a pain and often lead to issues

He's getting "soft starter" or "easy starter" confused with "hard starter"

Soft starters use digital logic (for lack of a better term) to decrease the the amp spike and by controlling the amount of current allowed to be pulled by an electric motor and spreads it out over time. If you look at a normal electric motor "start" on a graph, it's a instant spike of amperage that can be 5 times (give or take) the amount of current required to "run" the electric motor. That spike is only for a fraction of a second on the graph. A soft starter greatly lowers the current spike and spreads it out over a longer length of time. Don't get me wrong, it's still very quick, but it slows it down just enough to let a generator get the job done. (still less than one second)

A "hard starter" is simply an additional start capacitor wired in parallel to double the "kick" that is provided by the capacitor. This works fine to get tired old compressors going but it CAN greatly shorten the life of the motor/compressor....... this is what your electrician BIL is referring to.

A "soft starter" actually makes the "starting" of an electric motor LESS violent, and therefore they CAN lengthen the life of a compressor.

A "hard starter" actually makes the "starting" or an electric motor MORE violent, and therefore reduces the life of the compressor/motor.

There has never been ANY proof that a true "soft starter" is harmful to a compressor..... but it is generally known industry wide that "hard starters" will eventually kill a compressor. They were invented to get a little bit more service life from a compressor before they ultimately need to be replaced.

 

[Rick1953]

He's getting "soft starter" or "easy starter" confused with "hard starter"

Soft starters use digital logic (for lack of a better term) to decrease the the amp spike and by controlling the amount of current allowed to be pulled by an electric motor and spreads it out over time. If you look at a normal electric motor "start" on a graph, it's a instant spike of amperage that can be 5 times (give or take) the amount of current required to "run" the electric motor. That spike is only for a fraction of a second on the graph. A soft starter greatly lowers the current spike and spreads it out over a longer length of time. Don't get me wrong, it's still very quick, but it slows it down just enough to let a generator get the job done. (still less than one second)

A "hard starter" is simply an additional start capacitor wired in parallel to double the "kick" that is provided by the capacitor. This works fine to get tired old compressors going but it CAN greatly shorten the life of the motor/compressor....... this is what your electrician BIL is referring to.

A "soft starter" actually makes the "starting" of an electric motor LESS violent, and therefore they CAN lengthen the life of a compressor.

A "hard starter" actually makes the "starting" or an electric motor MORE violent, and therefore reduces the life of the compressor/motor.

There has never been ANY proof that a true "soft starter" is harmful to a compressor..... but it is generally known industry wide that "hard starters" will eventually kill a compressor. They were invented to get a little bit more service life from a compressor before they ultimately need to be replaced.

Thank you

 

[PCustoms]

Generators were never a real issue in the past . These days storms are intentionally generated .

My 8500W portable will run 2 dehumidifiers, deep well pump and combined 18,000btu window units no problem. It does not like when I add in the microwave...

Have not tried it on the new 18kbtu mini split yet.

 

[danski0224]

I have an Easy Air soft start on my 3 ton 2 stage unit, and it still pulls 30 amps.

 

[Dakotadadv8]

Shenanigans.

My cheapie 2.5 ton 14 seer units are pulling 2150 watts runnning. 7000? No idea how you came up with that.

My 10 ton pool heat pump plus the 2hp pump only pulls 7900. That little spike is the chlorinator turning on

Here is real data instead of google searches

agree so much BS info on the forum.

 

[WildBill]

Putting the Easy Start on my 20 year old, 3 ton, 13 seer AC dropped startup amps from around 70 to around 20, and running amps from around 17 to around 11. So I went from needing a 17K generator to about a 5k one to start and run my house AC. My 9k generator now starts and runs my AC easily when it wouldn't before, and has extra juice to run a bunch of other stuff at the same time. Also my lights no longer dim when the AC kicks on, it's very noticeably quieter running, and my summer power bill dropped about 30 percent compared to previous years.

 

[mike93lx]

Putting the Easy Start on my 20 year old, 3 ton, 13 seer AC dropped startup amps from around 70 to around 20, and running amps from around 17 to around 11. So I went from needing a 17K generator to about a 5k one to start and run my house AC. My 9k generator now starts and runs my AC easily when it wouldn't before, and has extra juice to run a bunch of other stuff at the same time. Also my lights no longer dim when the AC kicks on, it's very noticeably quieter running, and my summer power bill dropped about 30 percent compared to previous years.

How does a soft start change running amps?

 

[WildBill]

How does a soft start change running amps?

No idea, but it did. Measured using a good Fluke, which agreed with the Soft Start data.

I had the Fluke setup to see if their bluetooth app before and after numbers were accurate, which they were. Then I completely disconnected the Soft Start to make sure I wasn't nuts, and the start/running amps went back up to 70/17 from 20/11 with it installed.

 

[mike93lx]

No idea, but it did. Measured using a good Fluke, which agreed with the Soft Start data.

I had the Fluke setup to see if their bluetooth app before and after numbers were accurate, which they were. Then I completely disconnected the Soft Start to make sure I wasn't nuts, and the start/running amps went back up to 70/17 from 20/11 with it installed.

Must be magic.

Where was that power previously going? Unless the old cap was putting out a ton of heat, I cant picture how this works for running draw.

 

[WildBill]

Must be magic.

Where was that power previously going? Unless the old cap was putting out a ton of heat, I cant picture how this works for running draw.

It isn't supposed to lower running amps, I wasn't expecting it to, and it makes zero sense. This was done with a new cap and contacter installed on the AC, I had replaced both the week before. I am by no means an expert, but I do my own wiring and work as an industrial electronic tech, so I understand enough to be confused by it.

I installed it last spring but was adding R22 to my system for the first time last weekend and checked it, app and Fluke both still agree at 20/11.

 

[dscheidt]

Must be magic.

Where was that power previously going? Unless the old cap was putting out a ton of heat, I cant picture how this works for running draw.

it's an induction motor, it's got a power factor much less than one, which increases the observed current. I expect the he has a bad run cap, and the easy start is masking that, and improving the power factor.

 

[WildBill]

it's an induction motor, it's got a power factor much less than one, which increases the observed current. I expect the he has a bad run cap, and the easy start is masking that, and improving the power factor.

Was a new cap before the Easy Start was installed, and I had taken amp readings multiple times before I got the Easy Start with two different caps when troubleshooting the cap issue, which were very consistent. Whatever that's worth. I did notice it goes up by an amp or two when its been running all day and its really warm out, but that's the only variance I've seen in the with/without numbers. This was today, pretty hot out. It is 20 years old, maybe there is a compressor issue the Easy Start is masking somehow. Whatever its doing its pretty awesome, highly recommended even if it only reduces starting amperage.

 

[mike93lx]

Was a new cap before the Easy Start was installed, and I had taken amp readings multiple times before I got the Easy Start with two different caps when troubleshooting the cap issue, which were very consistent. Whatever that's worth. I did notice it goes up by an amp or two when its been running all day and its really warm out, but that's the only variance I've seen in the with/without numbers. This was today, pretty hot out. It is 20 years old, maybe there is a compressor issue the Easy Start is masking somehow. Whatever its doing its pretty awesome, highly recommended even if it only reduces starting amperage.

I am confident something else is at play. The soft start just cannot reduce running amps, plus it would be a huge marketing angle for them. They even explicitly call out that it won't do anything beside cutting peak demand

If you are not in a peak demand market, EasyStart will not save any money on your bill but is still can provide benefits like reduced surging and brownouts, quieter starts, and operation on smaller power sources.

 

[WildBill]

I am confident something else is at play. The soft start just cannot reduce running amps, plus it would be a huge marketing angle for them. They even explicitly call out that it won't do anything beside cutting peak demand

I wish I could figure out what, as I said already I know its not supposed to and I didn't expect it to. If I tell the Easy Start to relearn or remove it the running amps jump back up to around 20. I can watch the amps step down from 20 to 11 on my fluke and the app while its doing its five starts learning process. I'm thinking my ancient compressor is doing something weird. I'm really surprised every summer when it doesn't die. I just got around to checking the refrigerant after 20 years and it was about 50% short on R22, but somehow still putting out 45F air with a 20 degree delta between return air duct and floor registers (I usually keep my house between 64-68F). It is running a lot less to maintain temps now that I added some, and sounds smoother. But still pulling same amps.

 

[PCustoms]

Is your fluke somehow picking up on the harmonics?

 

[WildBill]

Is your fluke somehow picking up on the harmonics?

Both it and the Easy Start read the same, but I can try a different meter. My Fluke is the only one I have designed to measure start up amperage accurately but I have a couple I can check the running amps with. I'll check tomorrow if I still have all my fingers.

 

[larry4406]

@WildBill what brand/model easy start did you install?

 

[WildBill]

@WildBill what brand/model easy start did you install?

ASY-368-X48-BLUE

Amazon.com

 

[PCustoms]

ASY-368-X48-BLUE

Amazon.com

For that price I'll put one on my main line, ought to pay for itself in a few months with the reduced kW usage!

 

[Texanreloader]

Hey all!!! Finally got my Micro-Air soft start! Yay! Just hooked it up. Data panel showed LRA at 109. Connected to the Bluetooth in the unit and it shows peak 37. I am terrible at math. What does that work out to in watts? Will my Westinghouse 9500/12500 run it now? Y'all been great! Thank you.

 

[mike93lx]

Hey all!!! Finally got my Micro-Air soft start! Yay! Just hooked it up. Data panel showed LRA at 109. Connected to the Bluetooth in the unit and it shows peak 37. I am terrible at math. What does that work out to in watts? Will my Westinghouse 9500/12500 run it now? Y'all been great! Thank you.

37a x240v = 8880w

I think you are going to have problems as the generator will have to respond very quickly or it will brown out and trip, but it might work. Need to try

 

[Texanreloader]

37a x240v = 8880w

I think you are going to have problems as the generator will have to respond very quickly or it will brown out and trip, but it might work. Need to try

****

 

[mike93lx]

if its all setup, give it a try. really nothing to lose at this point

 

[Texanreloader]

if its all setup, give it a try. really nothing to lose at this point

Probably tomorrow. Just got everything cleaned up and put away after Beryl. Kind of tired of hearing it run.

 

[shaeff]

Update? I've been looking into these off and on for a few years now ever since reading about them on a different forum.

I've got two 2 Ton units. One has an LRA 62.9, the other is LRA 45. They were installed at different times, several years apart. I run them both off my Porter Cable H1000-ISW, 10,000 running watts, 19,500 surge. I make sure to run only one at a time, as one is for upstairs where bedrooms are, other is downstairs/main living area.

Generator takes it no problem but it grunts for about 2 seconds. Once running, all's well, no indication that I'm on generator power power aside from the buzz outside. Figured it'd be easier on the generator and the compressor when the thermostat calls for AC with one of the soft start units installed.

Lastly, I was under the impression that the Hyper Engineering Sure Start was the one to get, but after reading here... maybe not so much?

 

[Texanreloader]

Update? I've been looking into these off and on for a few years now ever since reading about them on a different forum.

I've got two 2 Ton units. One has an LRA 62.9, the other is LRA 45. They were installed at different times, several years apart. I run them both off my Porter Cable H1000-ISW, 10,000 running watts, 19,500 surge. I make sure to run only one at a time, as one is for upstairs where bedrooms are, other is downstairs/main living area.

Generator takes it no problem but it grunts for about 2 seconds. Once running, all's well, no indication that I'm on generator power power aside from the buzz outside. Figured it'd be easier on the generator and the compressor when the thermostat calls for AC with one of the soft start units installed.

Lastly, I was under the impression that the Hyper Engineering Sure Start was the one to get, but after reading here... maybe not so much?

From the Bluetooth read out, went from LRA 119 to LRA of 34.0 t0 34.6. Have not used it w/generator yet. Hopefully will never have to, but its there if I need it. 4Ton unit. Super easy install and C.S is right there if you need them.

 

[mike93lx]

From the Bluetooth read out, went from LRA 119 to LRA of 34.0 t0 34.6. Have not used it w/generator yet. Hopefully will never have to, but its there if I need it. 4Ton unit. Super easy install and C.S is right there if you need them.

Test it before you need it...