How do you get 3-Phase power to a residential workshop

[Dan T Jones]

I have been using a 5hp RPC from these folks for about 3 years. I also had 3 3 phase machines. I bought a used 3 hp motor on ebay for $60 and was in business.
https://phaseconverterusa-com.3dcart...tion=contactus
Dan

[Malcolm McLeod]

Can you get 3-phase power directly from the utility company, or must you use a rotary phase converter or a VFD?

Does a VFD replace a rotary phase converter (does it convert 1-phase to 3-phase), or do you just use it to control the power of already delivered 3-phase power?

You can get 3-phase power from the utility company. It is the standard in most industrial and/or business areas. Cost will vary greatly, depending on where you are: Is there 3-ph on the pole serving your property? Or is it 16 miles away, with a 1-ph branch line and feeder to your property? If it's close, is there a 3-ph transformer with it? Is it overhead or underground?

As others have said a VFD can replace a RPC, and a VFD can convert 1-ph to 3-ph. A VFD can also be used with a RPC (or 3-phase service) to control the speed, direction, and accel/decel/braking of a motor.

Why are VFDs de-rated he asked? (NOT)

• A 5Hp/230V/3ph motor typically draws ~15FLA per phase. A VFD for this motor would have its internal components sized to handle this 15A (plus some margin of safety).
• A 5Hp/230V/1ph motor typically draws ~28FLA per phase. A VFD for this motor has to have larger internal components to deal with the increased amperage. Lo and behold, a 10Hp/230V/3-phase motor draws ~28A, so you buy a 10Hp (3ph) VFD and use it for the 5Hp (1ph) motor. VFD is magically 'de-rated'. Edit: I should add that in this example the input section of the VFD handles 28A (1ph), and the output section handles 15A (3ph) - - both sections are handling the requisite 5Hp.

But this is old news. As Jack points out, manufacturers have begun to respond to the demand for 1ph VFDs and they will specify the HP/Amps/phasing that a given model will support - no user derating needed. Just read the specs before you buy.

[Tom Trees]

I got another VFD recently, I thought I was getting another Huanyang 3HP, but it happens to be an askpower/isacon drive.
Previous drive died because I stalled the motor on my bandsaw for far too long....I was really taking the pi**
I ended up needing the front panel board anyway, as the other Huanyang VFD had an issue with the relay after disconnecting it to test out another motor.

These Isacon/Askpower drives don't have the terminals for a braking resistor like the Huanyang does (although the Huanyang VFD's still need parts soldered on the board for a braking resistor to work)...
Also unfortunately, these newer drives need a relay aswell for a separate start and stop switch to work (3 wire control)

Another thing is, these have the same shutoff feature with the fan as your drives does Jack ...
I came into my shop yesterday to see that I had left it on for nearly two days
I keep the humming VFD for the tablesaw, as the bandsaw is a bit more of a now and again tool.

Funny, I find the Huanyang noisy and slightly irritating, but I find the quiet one scary if you forget it's on....
I should really get a relay, so I can use the emergency twistlock switch again

BTW These newer Isacon/Askpower drives have a blue sticker on the panel, and have tabs on top for opening up the casing.
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So can a 5HP VFD run a 5HP motor ...I was told you need a 10HP one aswell ?

Tom

[Malcolm McLeod]

~~~ So can a 5HP VFD run a 5HP motor ...I was told you need a 10HP one aswell ? ~~~

It depends...
Certainly if a VFD is rated for 5Hp at 230V/3ph, then it will run the equivalent motor if supplied with 3ph power. Each phase will pull up to 15FLAmps, and each component in the VFD is sized for this - inputs and outputs.

If the VFD is rated for 5Hp at 230V/3ph and you supply 230V/1ph to it, then you are feeding up to 28FLAmps thru a set of components in the VFD that are sized to handle only 15A. Magic smoke may emerge.

If a manufacturer rates a VFD for 5Hp at 230/1ph, then you can probably rest assured that each component string in the VFD's input section will safely handle 28FLA. The output section may be sized for 3ph (::15FLA). The output might even be sized to handle the full 28A on any leg (for a 1ph motor) - - but I am getting out of my comfort zone here - - so again, read the mfgr's spec carefully.

[Martin Wasner]

Magic smoke may emerge.

The Prince of Darkness, aka Lucas Electronics, has your back.

[Malcolm McLeod]

The Prince of Darkness, aka Lucas Electronics, has your back.

ROFL..... I need 2!

[Matt Day]

The Prince of Darkness, aka Lucas Electronics, has your back.

Could you post a link where I can buy that?

[Alan Lightstone]

So if I'm understanding this right:

1.) A single, properly sized rotary phase converter can be used to supply all the 3-phase equipment in the shop (with one device being used at a time) assuming it is sufficiently sized to handle the capacity (roughly twice the 5HP max I will need to enable the starting motor surges, or a 10HP unit).
2.) VFDs do exist that can handle the 5HP equipment, but I would likely need one per tool, each programmed separately.
3.) Jointers, Planers, Bandsaws, and Table saws do not need the variable speed adjustment that a VFD could provide.
4.) Rotary Phase converters include large motors, so will be loud themselves, in addition to the tools they power. VFDs are quieter (is this true??)
5.) 3-phase power to the residential home is likely to not be available, or potentially extremely expensive to obtain. (I'll have to check with utility about this).

[Malcolm McLeod]

So if I'm understanding this right:

...
2.) VFDs do exist that can handle the 5HP equipment, but I would likely need one per tool, each programmed separately.
3.) Jointers, Planers, Bandsaws, and Table saws do not need the variable speed adjustment that a VFD could provide.
4.) ... VFDs are quieter (is this true??)
...

Answers that I know:
2. Correct, but it is very likely that one could service all the typical home shop equipment - especially if of similar Hp. Put a receptacle on the output and plug in the chosen tool; just don't swap loads while the VFD is powered.
3. Probably true, but all can benefit from the accel/decel ramp available in a VFD. YMMV
4. Full disclosure - VFDs typically cause a motor to produce a harmonic hum or whine that some may find bothersome (I can't compare to RPC noise, since I don't RPC).

[Brad Shipton]

I don't follow why you want three phase for 5hp motors. Usually when you start buying used industrial machines they are in the 9hp+ range (big shapers, 10' sliding table saw, 16"+ jointer, 24" planer). Then you are beat. If you are buying used equipment with 5hp motors you could swap out the motors for what all the headache you will start with a VFD. My 10hp CNC spindle has a Mitsubishi VFD and I think it was $2k before installed.

[Alan Lightstone]

I don't follow why you want three phase for 5hp motors. Usually when you start buying used industrial machines they are in the 9hp+ range (big shapers, 10' sliding table saw, 16"+ jointer, 24" planer). Then you are beat. If you are buying used equipment with 5hp motors you could swap out the motors for what all the headache you will start with a VFD. My 10hp CNC spindle has a Mitsubishi VFD and I think it was $2k before installed.

Equipment that I'm looking at includes a Felder A941 Jointer (standard 3-phase, 5.5HP motor), Felder D951 Planer (standard 3-phase, 5.5HP motor), Felder FB710 Bandsaw (3-phase 7.5HP motor), Sawstop ICS (3-Phase 5HP motor - although available as 1-Phase 5HP). Other pieces of equipment are 1-phase.

I can get some, if not most of that equipment with less powerful 1-phase motors, but why???

[David Kumm]

Will the planer have a power table up and down? that would require a second vfd. for the machines you mention, I'd go rpc or PP. The electricals on Euro machines are a little more complicated to bypass and there may be motor brakes as well. I'd rather have the 7.5 hp motor on the 20" planer ( especially if the silent power head ) than the bandsaw but that is just me. Once you go three phase you will never really like single phase again. Dave

[Phil Gaudio]

I am going to go out on a limb here and say that (assuming you have overhead service in your area) if you look at the utility poles near your house and see 3 lines across at the very top, you are in good shape for potentially getting 3 phase. if you see only a single line:fugetaboutit.

[John Lanciani]

Equipment that I'm looking at includes a Felder A941 Jointer (standard 3-phase, 5.5HP motor), Felder D951 Planer (standard 3-phase, 5.5HP motor), Felder FB710 Bandsaw (3-phase 7.5HP motor), Sawstop ICS (3-Phase 5HP motor - although available as 1-Phase 5HP). Other pieces of equipment are 1-phase.

I can get some, if not most of that equipment with less powerful 1-phase motors, but why???

If I were in the fortunate position to be considering that list of equipment I would be looking at a PhasePerfect and nothing less. Buy once, cry once, and never have to worry about it again. Put in a 3 phase breaker panel on the load side of the PP and you're in the big leagues.

[Brad Shipton]

I follow you now, and I am guessing the change in budget will be fine once you get past the sticker shock. Did you ask Felder for a recommendation? I agree with David about 7.5hp for the planer. Beyond that, I will leave the electrical questions to others.

That is a nice list of machines.