Soft Start vs Hard Start for Compressors/Motors?

[ultrarunner]

With many of us wanting to do more with smaller generators or limited power I'm hoping those in the know will post the good and bad along with pitfalls to avoid when sizing and buying.

It almost seems like magic simply adding a small electronic gizmo let's smaller generators do the heavy start up often required for motors.

Aside from cost is there a downside to limiting starting amps?

Do Hard Start and Soft Start kits perform the same function?

Goodman sells a Hard Start kit for $60... Some of the Soft Start or Easy Start kits sold to RV trade sell for $300.

Are the dozens of products offered about the same or do some cut corners?

 

[om21braz]

You'll get some more technical advice than I have, but it all depends on the load which device is "best" or needed. An unloaded motor, say a motor turning a grinding rock versus one starting a compressor in a best case scenario require different methods of starting to most efficiently start and aid longevity. Determine exactly what the application is and that (energy efficiency, reliability, quick startup, etc.) will heavily factor in to if an additional device is helpful or maybe a necessity. I'll leave startup amp loads, high inertia loads, etc. particulars to those better equipped to explain the fine details.

 

[caver]

Look into Leaders in Custom Marine & RV A/C Controls, Soft Starters & Displays – Micro-Air, Inc.. I was going to get one for my last RV but then I sold it and just bought a bigger genny to replace my HondaEU2000i

 

[ultrarunner]

Yep... I'd like to do more with my Honda EU 2200i to power a small portable compressor.

Thinking larger it would be nice to be able to power Central A/C with the EM 5000.

Have yet to put my meter on the A/C to measure start up load.

Thinking larger... At work electricity is billed using demand factor... Been able to mitigate years ago by staggering start times and later with Johnson controls optimum Start/Stop.

At one time everything in the clinic started at 5 am... 6 package units, ventilation, etc... quite a spike.

 

[Industrial Toys]

I am just playing with my Powerbox, trying to get it ready for sale. Brand new, Generator, Welder, American Eagle Compressor. Trying to figure it out. Noticed an unloader valve, not connected to the pressure switch. Never knew such a thing existed.

Anyway, For soft start, one would have to somehow keep pressure off the pump until it came up to speed.

 

[grsthegreat]

Believe me, after many, many generator installs for owners having AC AND HEAT PUMPS. Look into Hyper Engineering soft start. After installing one of these in my own 4 ton ac unit, i went from near 97 amp starting load to around 22 amp(as i recall...about 22 amp). My generator hardly notices the ac starting up.

Look at post #4258. Heres an actual example of cheap hard start kit vs true soft start capabilities. https://www.tractorbynet.com/forums...-your-last-generator-maintenance-run-107.html

 

[ultrarunner]

Your endorsement is good enough for me...

Is there a difference between Hard Start and Soft Start or is it marketing?

 

[Industrial Toys]

Of course there is a difference. A motor can take many times it's running current to get started. Not with soft start.

Downside is complexity and cost. And another pice of expensive equipment that you cannot possibly repair when it fails. Then you are stuck with nothing in an emergency.

 

[ultrarunner]

Of course there is a difference. A motor can take many times it's running current to get started. Not with soft start.

Downside is complexity and cost. And another pice of expensive equipment that you cannot possibly repair when it fails. Then you are stuck with nothing in an emergency.

Here is a link to Goodman Hard Start Kit

GOODMAN Hard-Start Kit, Compressor Saver, Hard-Start Kit - 38GM4'|'CSR-U-1 - Grainger

Seems this Hard Start Kit and Soft Start both designed to assist with starting load.

 

[Popgadget]

Here’s a recap of my post on the other thread. I just installed a Hyper Engineering “Sure Start” soft start device on a Goodman 3-1/2 ton heat pump. I had previously installed a 521 Hard Start kit. Here are the peak measurements from each as captured on my Fluke clamp on. I have to say that I was surprised and impressed with the outcome. I would say that the soft start is worth the $275 price tag.
To be clear, the first measurement was with the hard start kit installed.