Anyone use soft starters?

Old buddy of mine was talking about a capacitor-enabled "green outlet" that an HVAC contractor installed for the motor starter on his mother's furnace. After spending a few minutes barking down internet rabbit holes, I found these thing-um-bobs, among others:

https://www.raymondinnovations.com/?...UaApiPEALw_wcB

I'm curious to know whether anyone here has used such devices on a planer, table saw, or equivalent "biggish" tool, and if so whether your experience was positive, neutral, or negative (no electrical puns intended, I swear).

So... any thoughts?

Thanks.

Cheers,

Jack

I'm not sure what problem you're trying to solve. I haven't heard of any problems with jointers, table saws, dust collectors, etc. from immediate starting. I suppose a more gentle start would put less stress on the belts or other drive equipment but I think most tools are designed to take the immediate start stress.

At least I haven't heard anyone complain about breakage that might be associated with a rapid start.

Some tools, such as routers, have a soft start but that's more for the person holding the tool than for the tool itself. On routers it's to prevent the tool from jerking out of your hands on start.

Mike

All of my big tools start relatively "softly" as it is...nature of induction motors. Any tools I have that feature "soft start" are universal motors (screamers), such as routers.

Those units achieve the soft start by providing a reduced voltage function. That's great for universal motors, but an induction motor is actually happier with full voltage starting. The better way, and the method used in virtually all industrial applications, is to use variable frequency to provide the soft start.

And Jack, keep the puns coming. There is no higher form of humor :)

I’ve used soft start methods for motors in excess of 100 HP, they’re not normally required for small motors.....Rod.

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Originally Posted by Jim Becker

All of my big tools start relatively "softly" as it is...nature of induction motors. Any tools I have that feature "soft start" are universal motors (screamers), such as routers.

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My Unisaw used to "bang" pretty hard on startup, since new. The SawStop that replaced it just kinda grunts and gets going.

The only tool I've got that I've got to really pay attention to on startup is my old Skil 77 worm drive. That little beastie gets put on the line after it's already spun up, because there's no way a 220-lb. lightweight like me can keep it from jumping when it's triggered. :eek:

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Originally Posted by Mike Henderson

I'm not sure what problem you're trying to solve.

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Trying to resolve my curiosity.

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I haven't heard of any problems with jointers, table saws, dust collectors, etc. from immediate starting. I suppose a more gentle start would put less stress on the belts or other drive equipment but I think most tools are designed to take the immediate start stress.

At least I haven't heard anyone complain about breakage that might be associated with a rapid start.

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Nor had I, so I thought I'd ask you guys. :D

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Some tools, such as routers, have a soft start but that's more for the person holding the tool than for the tool itself. On routers it's to prevent the tool from jerking out of your hands on start.

Mike

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Yes, I get that. I'm down to one handheld router, and it's a soft-start. The big honkin' old school router lives upside down, like a sleeping bat. I still have one 690 in a box, but I never did like clicking that toggle switch while trying to hold onto a pair of shiny doorknobs, and I find lately that my grip is not improving.

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Originally Posted by Rod Sheridan

I’ve used soft start methods for motors in excess of 100 HP, they’re not normally required for small motors.....Rod.

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That makes sense. I thought it kinda looked like a solution in search of a problem.

Thanks!

Many three phase machines over 5 hp come equipped with some sort of soft start. Star Delta starters are common. you can hear when they change over. The purpose is to reduce the startup amperage draw. Most of Felder's three phase machines are a soft start. The older German machines often had a manual wye delta start. Hold the switch until the motor spooled up and then swap to the second position for full power. Dave

I'll second Mr Kumm's post. Soft-Start circuits are (were?) common on industrial systems starting very large inertial loads - think big flywheel, rock crusher, or car shredder. Either you need a bigger motor or a 'bigger' ($$) contactor when starting loads are this high, relative to running loads. The motor either has to quickly accelerate the load (aka mo' power!) past the peak in-rush current, or the start circuit has to manage this in-rush in such a way as to not melt something (aka Soft-Start).

I'd probably say 10hp has been the tipping point for economical application of Soft-Starts, but that is just my personal experience. I'm sure there are a number a reasons, unknown to me, for a specific OEM to want a Soft-Start on 5hp or perhaps even less. For these smaller horsepower requirements, the starters may cost more than the motor, so often times it is cheaper just to slap on a bigger motor and use a simple (cheap) across-the-line starter.

FWIW, I think VFD cost reductions, increased life expectancy, and enhanced features have nearly killed Soft-Start applications. But certainly not all!

When I built industrial ventilation equipment I’d use them on large motors. Inrush current on a three phase motor is about 6x FLA. it’s for a short time, but it’s brutal. A soft start softens the blow. Do an across the line start on a 100HP motor some time. You’ll create a brownout without a soft start. You can knock a whole building worth of computers off line. It gets real ugly real quick.

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Originally Posted by Rob Luter

When I built industrial ventilation equipment I’d use them on large motors. Inrush current on a three phase motor is about 6x FLA. it’s for a short time, but it’s brutal. A soft start softens the blow. Do an across the line start on a 100HP motor some time. You’ll create a brownout without a soft start. You can knock a whole building worth of computers off line. It gets real ugly real quick.

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The fun part is standing in the MCC with a newbie when that 100hp contactor pulls in. For those that have never been there, it sounds like a train wreck. Live and in person. A change of clothes may be advisable!:eek:

I use mine on routers w/o soft start, the miter saw, etc. Any BRUSH-TYPE motor w/o soft start.

AFAIK all VFD's have an adjustable acceleration curve. For home shop motors 3 seconds is the general start up recommendation time. Same for the deceleration curve.
My dad said one time they were figuring this out for a big vacuum pump at work. Probably 200-500hp multiple belts driving it. They turned the power on and the motor grunted but could not rotate so they cut off one belt at a time until there was enough slip it could get to speed.
Bill D.