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View scribble's profile

3 Phase in your shop??

by scribble
posted 06-01-2018 07:51 PM


43 replies so far

View TheFridge's profile

TheFridge

10859 posts in 1966 days


#1 posted 06-01-2018 08:03 PM

You’ll have to include the cost of upgrading your service. 1500$ on the cheap side.

If you see a deal don’t let the fact that it’s 3ph ever dissuade you.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View scribble's profile

scribble

216 posts in 2680 days


#2 posted 06-01-2018 08:06 PM

When you say upgrade the service are you referring to going from 100 amp to 200 amp service in single phase?

-- If you can't read it Scribble wrote it!! “Experience is merely the name men gave to their mistakes.”

View TheFridge's profile

TheFridge

10859 posts in 1966 days


#3 posted 06-01-2018 08:08 PM

no. Mainly upgrading at minimum to a 3 ph panel with a main in it.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View scribble's profile

scribble

216 posts in 2680 days


#4 posted 06-01-2018 08:10 PM

Surprised the person at the electric company said nothing about that. He said it would be no charge for them to drop it to the mast I have on the garage from the electrician.
It will be a completely seperate system for the garage as my single into the garage is from the detached house.

-- If you can't read it Scribble wrote it!! “Experience is merely the name men gave to their mistakes.”

View Loren's profile

Loren

10477 posts in 4128 days


#5 posted 06-01-2018 08:26 PM

I’d just crunch the numbers on putting together
a rpc. Once you get above a 10hp converter
you’re also dealing with seriously heavy machines
as well and that involves moving them and
other fun activities.

There are plenty of “lighter” duty 3 phase
machines out there that can run with a 10hp
or smaller rpc. I think I’ve only got about
$400 into mine.

If you’re looking at 7.5hp shapers and wide
belt sanders then you’d be looking at a bigger
rpc and maybe at some point the $35 monthly
charge makes more sense.

View scribble's profile

scribble

216 posts in 2680 days


#6 posted 06-01-2018 08:27 PM

I actually was only thinking about it for a table saw as that is really the only major downfall I see in my shop. I can find delta 5hp unisaws with 52” fences for anywhere from 250-500

-- If you can't read it Scribble wrote it!! “Experience is merely the name men gave to their mistakes.”

View Loren's profile

Loren

10477 posts in 4128 days


#7 posted 06-01-2018 08:30 PM

Well, you’d be spending $420 per year for
the pleasure of being able to switch it on.

View scribble's profile

scribble

216 posts in 2680 days


#8 posted 06-01-2018 08:45 PM

Suggestions on setting up an RPC? I have heard that you loose HP with running convertors.

-- If you can't read it Scribble wrote it!! “Experience is merely the name men gave to their mistakes.”

View Loren's profile

Loren

10477 posts in 4128 days


#9 posted 06-01-2018 08:56 PM

Only with a static converter. Those cut the hp
by 1/3. A rotary converter doesn’t have that
issue. You can buy a Phase-craft or other panel
and wire it up to a 3-phase idler motor, which
can be found used for cheap. It’s pretty simple
to do and a lot cheaper than buying a rpc.

View AZWoody's profile

AZWoody

1458 posts in 1704 days


#10 posted 06-01-2018 09:02 PM

If you think you might go the vintage machinery route, I would do it in a heartbeat. If it’s just for one machine, that’s a tough call.

It would give you a lot of flexibility on used machinery though and you’ll be able to get some killer deals out there.

View scribble's profile

scribble

216 posts in 2680 days


#11 posted 06-01-2018 09:13 PM

im just in a small 1 car garage but getting tired of my small 3/4-1HP saw and would really like to upgrade to something with some decent power and considering i can get 3-5hp cabinet saws for under $500 i thought that may be the best route.

-- If you can't read it Scribble wrote it!! “Experience is merely the name men gave to their mistakes.”

View MrUnix's profile

MrUnix

7468 posts in 2679 days


#12 posted 06-01-2018 09:16 PM

I actually was only thinking about it for a table saw as that is really the only major downfall I see in my shop. I can find delta 5hp unisaws with 52” fences for anywhere from 250-500
- scribble

Then just add $200 for a VFD and reap the many benefits you will get going that route over straight 3-phase. There is no reason to have a recurring charge just to run one machine.

Cheers,
Brad

-- Brad in FL - In Dog I trust... everything else is questionable

View Fresch's profile

Fresch

450 posts in 2401 days


#13 posted 06-01-2018 09:22 PM



Surprised the person at the electric company said nothing about that. He said it would be no charge for them to drop it to the mast I have on the garage from the electrician.
It will be a completely seperate system for the garage as my single into the garage is from the detached house.

- scribble

That was because it isn’t his responsibility, they only go to the service point; that point is what you and your electrical guy come up with. Mast, demand meter can, wire, 3phase panel (buy it full of breakers, it’s cheaper that way), grounding, inspection/permits, circuits out of the panel.

View scribble's profile

scribble

216 posts in 2680 days


#14 posted 06-01-2018 09:43 PM

The $150.00 was the electricians portion to install panel, and mast. I will do the wiring in the garage.

-- If you can't read it Scribble wrote it!! “Experience is merely the name men gave to their mistakes.”

View ibewjon's profile

ibewjon

905 posts in 3273 days


#15 posted 06-01-2018 10:45 PM

$150 won’t buy anything electrical these days. Maybe the upgrade cost for an empty panel. Does the power company give you the meter socket free? Being an IBEW electrician for over 40 years, the prices do not seem possible. Remember if it seems too good to be true, it probably is. For a big shop, yes. For a one car garage, forget it. Remember, most places the rate for a service without a house is commercial, usually much higher. 3 phase (4 wire) cord, plugs and receptacles, breakers, pricey. Conduit a must, as the white wire in Romex can NOT be used for a hot wire. Marking is not approved. Plenty of good single phase table saw out there.

View TheFridge's profile

TheFridge

10859 posts in 1966 days


#16 posted 06-02-2018 12:15 AM

I go VFD nowadays.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View SteveGaskins's profile

SteveGaskins

757 posts in 3067 days


#17 posted 06-02-2018 12:21 AM

I would jump at the change to have 3 phase in my shop.

-- Steve, South Carolina, http://www.finewoodworkingofsc.com

View SteveGaskins's profile

SteveGaskins

757 posts in 3067 days


#18 posted 06-02-2018 12:21 AM

I would jump at the change to have 3 phase in my shop.

-- Steve, South Carolina, http://www.finewoodworkingofsc.com

View AHuxley's profile

AHuxley

874 posts in 3801 days


#19 posted 06-02-2018 02:59 AM

OK this is more simple than the thread might have you believe. You have a 1 car garage shop. You are considering adding one piece of 3 phase equipment which will cost you $150 plus $35 a month plus the cost of the 3 phase wiring in the shop. With that scenario VFD all the way, it will cost you more in the first month than the VFD will and the 3 phase premium will hit you every month from now own.

If you want to add several (say 4-5) 5hp or less 3 phase machines then get an RPC (or build one). Even an off the shelf American Rotary 10hp (5hp starting) RPC would pay for itself in less than 2 years (since you will still need to wire the shop with 3 phase).

If you plan to expand your shop physically and fill it with high horsepower 3 phase machines like wide belt sanders then a from the transformer 3 phase drop would be worth it.

Unless the OP significantly changes his plans this makes no financial sense, just spend some time researching VFDs.

View Aj2's profile

Aj2

2429 posts in 2278 days


#20 posted 06-02-2018 03:57 AM

I would go for the 3ph from the utility at that price it’s a steal.
I run a Kay Rpc I like how quite it is.
I would never suggest a Vfd because I can’t stand the high pitch whine they make.
Plus I’m not convinced they don’t damage direct drive motors.
Quite is better.

-- Aj

View AHuxley's profile

AHuxley

874 posts in 3801 days


#21 posted 06-02-2018 05:38 AM


I would go for the 3ph from the utility at that price it s a steal.
I run a Kay Rpc I like how quite it is.
I would never suggest a Vfd because I can t stand the high pitch whine they make.
Plus I m not convinced they don t damage direct drive motors.
Quite is better.

- Aj2

While I agree VFDs are not quite perfectly quiet some are better than others and normally aren’t very audible at 60hz. That said even the most obnoxious ones should only be an issue with machines that require no hearing protection most notably lathes.

Why are you concerned about VFDs damaging induction motors? The ONLY issue is insulation not up to the task of running motors at low Hz which can cause issues with non-inverter rated windings. While motor drives are relatively new in hobby shops (due to previous prices) it is actually a pretty mature field and has been used and studied in tons of industries around the globe. You simply are not going to damage an otherwise healthy motor running it with a VFD at its native frequency. Start lowering the frequency and you may have issues with heat (though anecdotally hobbyist level usage seems not to be much of an issue), start running at significantly higher than native frequency and you may see bearing issues.

I did think of one other scenario where I would want a 3 phase drop for even a single lower HP machine. If you have a high end Euro slider, shaper etc with tons of sensitive electronics you want very stable power, but even then I would balance the ongoing cost of the 3 phase service with the cost of a Phase Perfect.

View ArtMann's profile

ArtMann

1425 posts in 1296 days


#22 posted 06-02-2018 02:38 PM

At $150 plus an additional $35 per month, it wouldn’t take much more than a year for it to have been cheaper have just bought a single phase replacement motor instead if one table saw is all you expect to operate with it. As already pointed out, that much money doesn’t begin to cover the cost of a new breaker box and 3 phase wiring. Over the course of 5 years (or less), you would have been financially better off to just buy a brand new cabinet saw that operates on single phase.

View darthford's profile

darthford

612 posts in 2404 days


#23 posted 06-02-2018 03:15 PM


im just in a small 1 car garage but getting tired of my small 3/4-1HP saw and would really like to upgrade to something with some decent power and considering i can get 3-5hp cabinet saws for under $500 i thought that may be the best route.

- scribble

3ph will cost you $2,100 over 5 years minimum just for the $35 service fee, now how much money did you save on 3ph machines? If you want to bring in 3 phase have a better reason, a higher HP machine 7.5 hp 10 hp or something that won’t realistically run on single phase. 3 phase CNC machine. Something other than being able to purchase used 3 phase machines a few hundred cheaper than single phase.

If you have 200 amps single phase service at your house then you can run anything up to 5hp no problem. VFD, rotary phase converter are options for 3ph machines. You can purchase a single RPC rated for 5 hp and use it to run all your 3 phase machines up to 5 hp. No monthly service fee. If you currently only have 100 amps of single phase service your priority should be upgrading to 200 amps and a new 200 amp single phase service panel imo.

In some areas bringing 3 phase into a residential home sets off government alarms, they may take an interest in what you are doing.

View AHuxley's profile

AHuxley

874 posts in 3801 days


#24 posted 06-02-2018 04:30 PM



. You can purchase a single RPC rated for 5 hp and use it to run all your 3 phase machines up to 5 hp.

Just so there is no confusion a “5hp” RPC will not start a 5hp motor correctly. You generally want a 10hp RPC to start a 5hp single phase motor though there are situations you can get away with a lower HP idler.

View Aj2's profile

Aj2

2429 posts in 2278 days


#25 posted 06-02-2018 06:33 PM

I think many here are missing the point with three phase machines. It’s not really bang for your buck .
You can get some very good quality woodworking machines for very cheap because of the 3ph motors.
The joy and satisfaction of using a high quality machine is your reward.
Early this year I almost got the chance to own a Japaneese tablesaw.The quality of this saw was far above anything from China. It’s had a 3 ph and a very compact saw cabinet.

-- Aj

View crank49's profile

crank49

4032 posts in 3451 days


#26 posted 06-02-2018 06:49 PM

Just a thought you might not have thought of, Solar power inverters generally don’t cost more in 3 phase than single phase. And the power is free of monthly donations to the electric company. You have to buy the solar power system of course, but at least after its paid for the cost is $0.00

View darthford's profile

darthford

612 posts in 2404 days


#27 posted 06-02-2018 07:08 PM

. You can purchase a single RPC rated for 5 hp and use it to run all your 3 phase machines up to 5 hp.

Just so there is no confusion a “5hp” RPC will not start a 5hp motor correctly. You generally want a 10hp RPC to start a 5hp single phase motor though there are situations you can get away with a lower HP idler.

- AHuxley

A RPC rated to run a 5hp motor will start and run a 5hp motor. The RPC motor that’s generating the 3 phase power will itself be 7.5hp to 10hp motor, so correct its not a 1 to 1 hp single phase to three phase. You can get away with somewhat smaller RPC motor say 7.5hp depending on the 5hp 3 phase machine you are powering. If you are trying to start up a 3 phase machine that’s hard to start like a dust collector or manual metal lathe a larger RPC motor may be required.

View Loren's profile

Loren

10477 posts in 4128 days


#28 posted 06-02-2018 07:19 PM


Early this year I almost got the chance to own a Japaneese tablesaw.The quality of this saw was far above anything from China. It s had a 3 ph and a very compact saw cabinet.

- Aj2

What kind of saw was it? I’ve seen pictures of
a few Japanese table saws and found the designs
interesting. Of course saws vary worldwide
with a plethora of design styles in Europe, but
the rarely make it to N. America.

View ibewjon's profile

ibewjon

905 posts in 3273 days


#29 posted 06-02-2018 07:21 PM

If the saw or other tool is free, it will cost you more in the future for three phase than a new motor. Give me $35 a month for life, I will buy the new motor.

View ibewjon's profile

ibewjon

905 posts in 3273 days


#30 posted 06-02-2018 07:32 PM

If the saw or other tool is free, it will still cost you more in the future than a new 1 phase motor. Send me the $35 for life, and I will buy you a motor.

View Aj2's profile

Aj2

2429 posts in 2278 days


#31 posted 06-02-2018 07:51 PM


If the saw or other tool is free, it will still cost you more in the future than a new 1 phase motor. Send me the $35 for life, and I will buy you a motor.

- ibewjon


Sometimes you cannot swap motors. So if one wants the take advantage of the machine they don’t have the luxury to think about being frugal.

-- Aj

View AHuxley's profile

AHuxley

874 posts in 3801 days


#32 posted 06-03-2018 03:01 AM


. You can purchase a single RPC rated for 5 hp and use it to run all your 3 phase machines up to 5 hp.

Just so there is no confusion a “5hp” RPC will not start a 5hp motor correctly. You generally want a 10hp RPC to start a 5hp single phase motor though there are situations you can get away with a lower HP idler.

- AHuxley

A RPC rated to run a 5hp motor will start and run a 5hp motor. The RPC motor that s generating the 3 phase power will itself be 7.5hp to 10hp motor, so correct its not a 1 to 1 hp single phase to three phase. You can get away with somewhat smaller RPC motor say 7.5hp depending on the 5hp 3 phase machine you are powering. If you are trying to start up a 3 phase machine that s hard to start like a dust collector or manual metal lathe a larger RPC motor may be required.

- darthford

What you said is absolutely accurate but it is also the genesis of the confusion for some new to 3 phase and what I was trying to illuminate. If you go to American Rotary for example and click on one of their 5hp RPCs and buy it you will get a RPC with a 5 hp idler NOT a RPC rated to start even a light load 5hp motor. They market them this way because the size idler you need is not a one to one ratio and it varies with the starting load of the machine. A tablesaw is an example of light or type 1 starting loads, air compressors are heavy or Type 3 starting loads.

In hobby use you can sometimes get away with an underrated RPC but that sort of advice falls into the do as I say not as I do category.

View Loren's profile

Loren

10477 posts in 4128 days


#33 posted 06-03-2018 03:17 AM

Starting a hard starting motor with an undersized
rpc can cause chattering of the contacts in a magnetic
switch or even burn them so bad the switch has
to be replaced. They corrode anyway with use.
I have a machine that I got started once or twice
with my old rpc before I smoked the old switch on
it. I didn’t look the switch contacts over before
doing it but after I smoked it they looked like
they were corroded before… in any case I was
asking too much of the rpc. I replaced the switch
and upgraded the rpc.

View ibewjon's profile

ibewjon

905 posts in 3273 days


#34 posted 06-03-2018 12:59 PM

Install a 3 phase generator, just to run the shop, natural gas is fairly cheap, and shut off when not using it. But not every time you start the saw.

View AHuxley's profile

AHuxley

874 posts in 3801 days


#35 posted 06-04-2018 07:52 AM



Install a 3 phase generator, just to run the shop, natural gas is fairly cheap, and shut off when not using it. But not every time you start the saw.

- ibewjon

How is that going to be remotely economical compared to a VFD, RPC, utility drop or changing the motors on every 3 phase machine he buys? While you can get a portable gas powered 3 phase generator for 700-800 bucks a new permanently installed NG/Propane 3 phase generator is going to run you 5-6 grand. Add to that the roughy tripled cost per kWh along with the ongoing maintenance and it is by far the least financially palatable option.

View ibewjon's profile

ibewjon

905 posts in 3273 days


#36 posted 06-04-2018 05:38 PM

No, a generator makes no sense, but I threw it out there because it makes as much sense as paying $35 a month forever, or a rotary phase converter. Why run an electric motor operated generator and an idler motor just to run a saw. VFD is the only sensible thing, but it seems like no one understands that. I have plans to buy a VFD for my lathe for speed control.

View jonah's profile

jonah

2075 posts in 3778 days


#37 posted 06-04-2018 06:16 PM

There’s no way it makes sense to pay $35 a month in perpetuity just for access to 3-phase power in a single car garage. That is a tiny space, and there’s no realistic tool you’re going to be using in there that absolutely requires 3-phase power.

You can always replace a tool’s motor. You can’t get the $420 a year back from the power company once you commit to paying it.

View CyberDyneSystems's profile

CyberDyneSystems

288 posts in 2668 days


#38 posted 06-04-2018 07:05 PM

As much as I love old heavy machinery, I would not advise this in your case.

For one machine, it’s really not worth it; either in time, effort, or annual costs. Sure if you had plans for a shop full of old 3 phase tools; heavy duty thickness planer, Oliver sliding table saw, and an old M-head Bridgeport for metal work, but for one saw?

Much better to pay the upfront on a decent used Unisaw etc. with single phase motor.

I found and old 1942 in near mint condition with the old “Bullet” motor (110v single phase) for only $400.00 a few years back.

Likewise my monster 12” 1945 DeWalt R.A.S is 3HP single phase (220 of course) Again, it was $350.00 complete and working.

Shopping around is easier time spent. And no hidden monthly fee.

-- Without the wood, it's just working

View AHuxley's profile

AHuxley

874 posts in 3801 days


#39 posted 06-05-2018 04:36 AM



No, a generator makes no sense, but I threw it out there because it makes as much sense as paying $35 a month forever, or a rotary phase converter. Why run an electric motor operated generator and an idler motor just to run a saw. VFD is the only sensible thing, but it seems like no one understands that. I have plans to buy a VFD for my lathe for speed control.

- ibewjon

I broke it down earlier and no one understands that a VFD is the only sensible solution because it isn’t depending on a person’s needs and while the OP’s current situation leans hard toward a single VFD he needs to consider his long term plans.

1. VFDs make financial sense if you only plan to power 1 or 2 5hp or lower machines in a shop and/or if you need more advanced motor control like speed control, soft start, braking or need to program ramp up and coast down profiles etc. I, for example, could not run my 7.5hp shaper nor my 7.5hp bandsaw via VFD with single phase input. While I think a VFD is the right choice for the OP it is not the correct choice in a lot of situations. An older lathe is an excellent candidate for a VFD, part of the reason that most every higher end lathe sold today runs a 3ph motor via VFD. The only issue there is how well a non-inverter rated motor’s insulation will deal with low frequency power.

2. RPCs make sense if you have or plan more than 3 3ph machines or you plan to run higher hp machines. 3hp single phase input VFDs used to be the cutoff but 5hp is more viable now with the introduction of cheap direct from China alternatives, though I am still dubious of them many people have good luck and there is lots of internet community support for them, the early adopters were flying blind with poor documentation and support. The bottom line the more 3ph machine you have (or plan) and the higher HP those machines are the more RPCs become the most viable choice.

3. There are some applications where extremely well balance power is important and that’s when you look to Phase Perfect. CNC machines and Euro sliders and shapers with high levels of electronics are examples of this.

VFDs are great in the proper application and a poor or useless option in other applications. It appears the OP’s best option is a VFD but he hasn’t divulged any possible future plans.

View Fresch's profile

Fresch

450 posts in 2401 days


#40 posted 06-05-2018 01:30 PM

So scribble,
The horse has been beat to death, what cha gonna do?

View scribble's profile

scribble

216 posts in 2680 days


#41 posted 06-05-2018 02:12 PM

I am going to pass on doing the 3 phase at this time in this current housing location. I will just keep looking for a heavy duty single phase saw to upgrade to.

-- If you can't read it Scribble wrote it!! “Experience is merely the name men gave to their mistakes.”

View darthford's profile

darthford

612 posts in 2404 days


#42 posted 06-05-2018 02:20 PM


3. There are some applications where extremely well balance power is important and that s when you look to Phase Perfect. CNC machines and Euro sliders and shapers with high levels of electronics are examples of this.
- AHuxley

American Rotary is the only RPC approved by Haas to run Haas CNC machines, as RPC’s go they are among the best. NOT cheap though. I purchased one with all the add-ons ouch!

View CyberDyneSystems's profile

CyberDyneSystems

288 posts in 2668 days


#43 posted 06-07-2018 02:50 PM

I saw a minty Unisaw on eBay over the weekend. starting bid was $300.00

https://www.ebay.com/itm/DELTA-ROCKWELL-10-UNISAW-34-466-3-HP-1-phase-motor-table-saw/123173091454?hash=item1cadb0387e:g:bbIAAOSweUNbFeYu

Of course local pickup, location is the problem with these deals, but it does mean when they come up, not many bidders. This is exactly how I got mine for $400.00

-- Without the wood, it's just working

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