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What does the label on the condensing unit have for LRA?

A gen that size might start the A/C, but it may need a soft start kit so that you still have enough amperage available to run other things too:
 

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@Glez - I'm not sure off the top of my head what the tonnage is of the central AC unit we have, but it is on a 40a breaker. Our 15kw rotary - even on natural gas - doesn't hesitate with it. You can tell when the AC kicks on easier on natural gas than you can gasoline, on gasoline you can't really tell when the AC load hits it unless you're right next to the gen.

I know that isn't a scientific answer - but I would say our 15kw is overkill. If you stack up all the house loads that could possibly run in an extended power outage, to be frank - we have no power outage. With the 15kw there is 0 reason to be picky on loads (like not running the microwave with the AC running) - it takes it all.

I would imagine you won't have too much trouble starting/running your AC on an 11.5kw starting/9.2kw running rated gen. However, you won't have the head room on wattage like we do - which is what GenKnot is getting at. A soft-start is always a good idea.

For the sake of discussion/more complete info - unless we need AC we don't need the 15kw. We've used our old 2600w rotary for emergency power in storms to run essentials - we can get by with it. That was before I got a Honda EU2200i inverter. Just recently we got a Champion 5500w inverter (120v only). The Champion will be the primary backup - it has the head room to comfortably run everything (including microwave) that the other 2 smaller gens didn't have, but with a lot better fuel consumption rates than the 15kw. The 15kw runs 1.5gal gas/hr. I am not sure what the NG consumption is off-hand, but the gas figure might give you a baseline - a lot.
 

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Im wondering if a 11.5 kw surge / 9200 kw continuous generator will run a 3 ton ac unit? The breaker on the ac is 35 amps.
Ought to.
Running a 3 Ton Coleman Echelon two stage HVAC with Hyper Engineering Sure Start. On Propane 8500 Watts Running / 11200 Watts Surge. De-rated another 21% for 6000 feet above sea level for 6700 Watts running / 8848 watts surge. HVAC starts with a noticeable tug on the generator but recovers in about 1/2 second. With AC on stage two (HI), and the house test load I am drawing a smidge over 4KW nicely balanced. There is enough head room for the microwave (1400 watts). Note that I do not have any major appliances on the transfer switch save for the refrigerator and microwave but every other outlet and light has power.
 

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@Glez: For 10 years I ran a 108 LRA heat pump on a 14 KW Generac.
The Generac died and I installed a 16 KW in its place three years ago.
In the spring we went thru an outage and the 16 KW had a difficult time starting the 108 LRA heat pump.
I managed to sneak by for the few hours that we needed the Generator.
Each time the HP started I thought the Gen was going to die.
I ordered a Soft start for the HP and just last night we had another outage that lasted well after midnight.
The Generator never balked once.
I would consider a larger Generator for the 3-ton unit.
Or anti up $350.00 for the soft start, which you will possibly have to do anyway.
 
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Discussion Starter · #10 ·
Good info and thanks for the help. The soft start is interesting and looks like a good solution if the generator can't handle the load. I may get it just because it literally takes the load of the gen.

This is my power estimate; It multiplies the # of units by the expected power need in the 2nd column. With everything running all at once I need about 5 KW no AC and 7.5 with.

KWNo AC - #KWAC - #KW
Ceiling Fan0.14
0.4​
4
0.4​
Lights0.18
0.8​
8
0.8​
TV0.32
0.6​
2
0.6​
Fridge11
1​
1
1​
Coffe Maker0.61
0.6​
1
0.6​
Garage Door Opener11
1​
1
1​
A/C Continuous3
0​
1
3​
4.4​
7.4​


The generator is a new Champion with EFI, gasoline. I expect it to be responsive to load changes.

 

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If you are looking at that size gen, I would consider the WEN. It is dual fuel, but not EFI.
 

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Discussion Starter · #13 ·
I think you are underestimating the A/C unit. It should be closer to 4,660W.
Forgot the fans. With updated numbers it doesn't leave much room if everything is running at the same time and the AC kicks on. Now, I'm a bit concerned that the gen isn't big enough. I had a 12/15 KW on order but when you bump to the next size they become pretty heavy for a "portable", 320 LB. I live in a development where a standby unit isn't allowed, has to be portable and no propane storage.

Would a larger EasyStart help, this one is for a 6 ton AC?

 

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That WEN is just about the same size as the Champion. Does it handle surges different or better?
It has a little bit more power and it is significantly cheaper. Too bad you can't use propane because long-term storage is an issue for gasoline. But the gen having dual fuel capability might make it easier to sell down the road.
 

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Since the A/C seems to be the power hog, have you considered getting by with either window or portable A/C units? I do not run my central A/C, so we get by with a 5KW GN625i. We are natural gas though, so that helps a bunch. I have converted my gen to natural gas.
We have an inverter Midea 8,000 BTU window unit. The inverter A/C units are very efficient. It won't cool the entire house of course, but in a blackout we can get by with it. Midea also makes portable dual hose units:
 

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Discussion Starter · #18 ·
Since the A/C seems to be the power hog, have you considered getting by with either window or portable A/C units?
I live in FL now, AC is a must. Came from NJ and we would loose power for a week at a time. The year before Huricane Sandy we lost it for 2 1/2 weeks in the span of 3 weeks. Sandy was another week and I was sweating out them getting propane to me cause of roads being closed so after that I put a 1000 gal propane tank in. Honsetly, they kept power on longer in Beriut then they did in Jersey. I had 6 1/2 tons of AC and a well pump. A 20 KW Kolher standby did the trick.

My plan is to put a soft start on and if I have problems I'll sell the gen and move up in power. I need to get an extra fuel tank and a pump.
 
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