A/C soft start

[Hughman]

Anybody install a soft start device on their central a/c? Looking at one of these:

EasyStart™ Flex: Soft Start AC Home Starter

Micro-Air Home AC Soft Starter lets air conditioners and heat pumps up to 6 tons run smoothly on backup generators, ensuring comfort even during power outages.

www.microair.net

Thinking it might allow me to start the a/c while running the house on my PTO generator (15kw WinCo). The a/c is a 5 ton unit.

 

[grsthegreat]

ive installed them, but not that brand..\

i used hyper engineering brand.

Soft Start Single-Phase | Eltwin

www.eltwin.com

 

[grsthegreat]

a soft start takes about 60% of the starting load off of the air conditioner. it dropped mine from nearly a 100 amp start load to under 30 amp peak.

5 ton on a 22kw generac

 

[ponytug]

+1 on hyper-engineering, but I know that there are several other close competitors out there.

All the best, Peter

 

[caver]

Micro Air has been selling them for RV's for many years. People that have installed them seem to be happy with them. It allows an RV A/C to be started using smaller inverter generators. For what one was going to cost me I elected to sell my old Honda 2000i and get a chinesium Champion 3500 unit.

 

[RayIN]

Look at how they work before buying. I think they shorten the lifespan of the compressor motor.
Compare a soft-start to a hard-start vs standard start.

 

[Phil Timmons]

Anybody install a soft start device on their central a/c? Looking at one of these:

EasyStart™ Flex: Soft Start AC Home Starter

Micro-Air Home AC Soft Starter lets air conditioners and heat pumps up to 6 tons run smoothly on backup generators, ensuring comfort even during power outages.

www.microair.net

Thinking it might allow me to start the a/c while running the house on my PTO generator (15kw WinCo). The a/c is a 5 ton unit.

Yeah, generally a good idea when a compressor motor is a generator load. We recommend and use them with Solar PV + Battery systems, as well.

Particular issue with the specific one you have there . . . they seem to leak. Water, that is, if left outside. IRRC, there is an O-Ring that looks like it should seal around the surface, but we always see water and vapor in them when left outdoors. May leak rainwater around the screws, dunno -- never dug in that far. So when we see them, we dry them out and then get them indoors or in an enclosure.

 

[Phil Timmons]

Look at how they work before buying. I think they shorten the lifespan of the compressor motor.
Compare a soft-start to a hard-start vs standard start.

They take the peak off from the Inrush Current. When a compressor or pump (air, water, freon, whatever) starts up from zero with existing head pressure, rotation is slowed by the existing load, and it acts like a Locked Rotor, which makes the AC current see the motor as a DC short. Makes the current or amps jump to 6X or more the full operation current. Soft starters limit the Inrush Current, and bring the speed of the motor up to full speed across a time delay.

 

[grsthegreat]

Look at how they work before buying. I think they shorten the lifespan of the compressor motor.
Compare a soft-start to a hard-start vs standard start.

No, they lengthen the life of the compressors. Hard starters are used as a last resort for failing compressors

 

[RayIN]

No, they lengthen the life of the compressors. Hard starters are used as a last resort for failing compressors

I wonder why RVP/ ColemanMach model 6535 basement air conditioners come from the factory with hard-start units atop the capacitors?
Like Phil Timmons said, a soft-start unit extends start-up time, which is supposedly harder on the most motors.

 

[ponytug]

I wonder why RVP/ ColemanMach model 6535 basement air conditioners come from the factory with hard-start units atop the capacitors?
Like Phil Timmons said, a soft-start unit extends start-up time, which is supposedly harder on the most motors.

This may be word use/labelling.

That said, a factory might install relay controlled hard start devices on new units if the anticipated use was for short cycling, or in a low voltage environment, but I would distinguish between relay switched starting capacitors (useful, and good for the compressor), and what are generally referred to as hard starters with PTC (positive temperature control) that leave too much current in the motor for to long. The latter are harmful as they are universal and not motor specific...

This Coleman optional "hard starter kit" appears to me to be a PTC hard start, so I hope it is not like this from the factory.

9333-9021 / 8333-9021 / 8333A9021 - Coleman Mach Start Device

Air Conditioner Capacitor; Hard Start Kit; Replacement For Coleman Mach 46413/ 48203/ 48204/ 48207/ 48208/ 48213/ 48253/ 48254/ 48257/ 48263/ 48264/ 48268/ 6633/ 6636/ 7333/ 7633/ 8333/ 8335/ 8433/ 8534/ 8535/ 8632/ 8633/ 9013/ 9021/ 9031/ 9201/ 9202/ 9232/ 6799/ 46515/ 48004/ 48008/ 48014/...

www.rvproductsshop.com

This would be additive to a factory relay controlled starter by the looks of the schematics.

So, I don't know, but I think that the factory might install a good "hard starter" with a relay, and offer up the other for adding to it for problem installations, with short cycling (failing compressor/refrigerant issues) or low system voltage.

All the best,

Peter

 

[grsthegreat]

I wonder why RVP/ ColemanMach model 6535 basement air conditioners come from the factory with hard-start units atop the capacitors?
Like Phil Timmons said, a soft-start unit extends start-up time, which is supposedly harder on the most motors.

High end ac units, like lennox include soft starters to extend motor use. We also place soft starts on deep well pumps to extend their life.

Why would you think they harm motors.

 

[Phil Timmons]

I wonder why RVP/ ColemanMach model 6535 basement air conditioners come from the factory with hard-start units atop the capacitors?
Like Phil Timmons said, a soft-start unit extends start-up time, which is supposedly harder on the most motors.

whoa.

Sorry, not the intended concept. The high INRUSH Current is what damages motors under load.

Generally -- Soft Start = GOOD.

But if you are operating on a Generator, this is all more about keeping the load lighter on the Generator. THAT is why you are doing this. Should have no adverse effect on the Air Conditioning Compressor motor