Category5
Our 17.5 kw generator has 26.5kw starting power and last storm our generator bogged down when starting the AC.  Also, after 36 hours we had a fried regulator (which ay have to do with trying to run a tankless heater, just a single leg, for a lukewarm shower).

I got a Hyper Soft Start, 16-32RLA version since my AC says it is rated at 27.5 RLA.  Couldn't find anyone to install it until today, I finally had a guy come to do it, and he called Johnstone (he had never seen one) for guidance and they told him not to install it if we have a variable speed compressor.

I had sent the AC unit label to Hyper Engineering and they recommended the model, so I am confused.  Is Johnstone and our AC guy right?  Or is this thing still the answer to our issue?

Thanks!
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Category5
By the way, the unit is a Goodman 5 ton, with variable compressor.  It has a pretty big circuit board in there by the capacitor.  The AC tech told me variable speed compressor usually start slow anyway, and ramp up, so shouldn't even need a soft start.
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Cobranut
Are you sure the compressor is variable SPEED, and not multi stage? 
Many air handler fans are variable speed, but most compressors I'm aware of have 2 or more stages of bypass, but still turn at a constant speed. 
I'd suspect controlling noise and harmonics would be a challenge for a variable speed unit. 
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Category5
IMG_7591.jpg    

https://www.goodmanmfg.com/products/air-conditioners/18-seer-dsxc18
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Cobranut
According to that link the compressor is a 2-stage.
Basically, it has a bypass that can open to allow part of the refrigerant to recirculate back to the inlet, reducing head pressure and load on the motor when full cooling or heat output isn't needed. 
The motor still runs at the same speed, so I see no reason a soft-start kit wouldn't work on it.
BTW, I suspect these usually startup with the bypass open, which would shorten the duration of the starting current spike.
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78buckshot
The Soft Start kit comes with detailed install instructions, not hard to follow. Johnstone Supply is an HVAC distributor, they handle Goodman among other brands of equipment and parts. The counter sales folks may have some prior field experience but are generally not HVAC techs. It would be best to contact Goodman again with all of the info you can provide and get their blessing on modifications to the condensing unit. The compressor is probably compatible with the Soft Start but the control board/s may not be happy with it and they are a little pricey to use on an experimental basis.
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Category5
Hmmm.  So since it’s a dual stage it should work.  I guess the problem was the mis identification of the compressor as variable instead of multi speed.  

Goodman is of no help.  They don’t know what a hyper soft start is.  Lol
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BillM
I've had bad luck with Goodman, I used to gravitate to them like a hooker at a USMC convention because I don't think there is a cheaper HVAC unit on the globe and I'm as cheap as they come.  The support from the factory and the regional rep was horrible when I needed help from them on pairing their unit with a different furnace.  But I just recently installed a Sure Start I bought online from Ziller.  I think my pucker factor hit a 3 at one step, but the install went smoothly and right away I could 'hear' a difference in the start.  Quieter.  I totally recommend you install it if it's compatible of course.  When you read all the 'features' of it, which is nearly 2 pages long, it seems like a must have.
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78buckshot
Category5, if it is single speed, two stage you should be good to go as Cobranut said. I didn't research your model number but most of the newer two stage are scroll single speed motors that unload part of the refrigerant back into the suction side of the compressor. It is accomplished by opening an internal valve with 24 VAC on low stage and closing that valve on high stage, it reduces the head pressure when unloading thus reducing the current needed to turn the compressor with a surmised energy savings.
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Category5
Thanks for all the replies guys.  I am still out of town but will get the unit installed when I get back.  I contacted hyper engineering directly as well, and they got back to me stating the soft start would indeed reduce my load on the generator and would be an ideal fit for my unit.  Too bad more ac companies don’t know about this device.  I’m sure they’d upsell them just about every time they did a new install.  
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