Rotary Phase Converter questions

[DavesGarage]

Hi Guys!
So my shop is up and operational now, been busy as heck! My neighbors son in law builds rv gates and he brought in a flatbed 6.0 Ford that he squired that needs a lot of attention. He dangled a Dake cold saw in my face in trade for work on this truck. I know basic residential electricity but zero experience with phase converters and 3 phase electricity.
I have a few friends that are electricians by trade, one is residential (a), one used to be commercial years ago but has been residential for the last 20 years (b) and the last one is only commercial (c). Electrician "a" is no help right now, "b" lied to me and "c" is laughing about it. B basically told me the Dake saw was bitchin and could be three phase or single phase so I agreed to take the saw in trade (its not perfect but I can make it like new). Just discovered "b" was full of poop and didnt know what he was saying. The motor and all electronic controls will have to be swapped out to single phase to make it work. He said I could install a phase converter to make it work but I didnt want to spend a bunch of money to make the saw work. I found a company locally "Phoenix Phase Converters" that has very affordable converters but I cant find much for reviews on their equipment or customer service. Anyone have good or bad info? Neither a,b or c have any experience with this brand.

Another question, this saw on high speed is 2.5 hp, will a 3 hp phase converter be enough?

Thanks for any help fellas!

 

[Lamakocklee]

Not familiar at all with that saw, but another option is to use a VFD

https://www.surpluscenter.com/Elect...quency-Motor-Drive-WJ200-022SF-CP-11-3630.axd

You could use a static phase converter if desired or even make your own rotary if you just add the idler motor to a static phase converter. The thing is if you get one piece of 3 phase equipment, it tends to open the door for other pieces of 3 phase equipment. Basically what that means is go big

 

[Lamakocklee]

Here is an example of getting a kit.. just supply your own idler motor.

http://phaseconverterusa.com/Phase-Converter-kits-Rotary-Style-_c_23.html

I might have purchased from this place a long time ago.. but my failing memory is failing me right now.....

 

[DavesGarage]

Ive thought about that as well. I already have most everything I think I would need except for a plasma cutter.....someday. Already out of room nearly so I cant go with anything too big. Never would have thought 2260 square feet was not good enough

 

[Lamakocklee]

The VFD is nice as it would allow motor speed control if you can use it along with softer motor starts. Not sure how the controls are wired up. You may have to bypass it if you use a VFD.

 

[Dagny]

Get an electrician who is familiar with VFD s . that is best but your saw might not like it. If it has other controls.

 

[Robert Haas]

VFD is not in the same league as a RPC. VFD's reduce the actual power.

I have had both powering my Mill and replaced the VFD after only a couple weeks, My Mill did not like the VFD.

 

[Kev In]

You always need a phase converter that is rated at 2.5 hp or larger.....you shouldn’t use a converter rated less than 2.5 hp.

If you want a great VFD, look at KBAC....they are a little pricey, but they are dust and water proof, which in a shop is a must.

 

[larry_g]

https://www.americanrotary.com/?gclid=EAIaIQobChMInYaRn4aO2wIVDcRkCh133gWAEAAYASAAEgJODvD_BwE

Above is another player in the rotary field. I built my own some 20 years ago and it is still powering multiple tools in the shop.

lg
no neat sig line

 

[930dreamer]

I'm thinking a 5hp rotary phase converter should work just fine as its twice the hp of the motor you want to start, unless you plan on more 3 phase machines?

 

[Daves69]

I used http://www.speedy3phase.com/ and was pleased with their service. Have a 7 hp lathe and the converter does not have any problem keeping it running.

 

[Bert_]

VFD is not in the same league as a RPC. VFD's reduce the actual power.

I have had both powering my Mill and replaced the VFD after only a couple weeks, My Mill did not like the VFD.

Not true at all, where did you get this info?

VFD's are used all throughout the industry without any reduction in power. Provided that the VFD is sized correctly it will accept single phase power and run the motor at full power.

Maybe you are thinking of a static phase converter? Those just give the motor a kick to get started and then run the motor on single phase.

 

[Norcal]

Not heard any good about Phoenix Phase Converters, a friend bought one to run a Norfield door machine & had issues with it, think he bought it on eBay.

 

[larry_g]

Not true at all, where did you get this info?

VFD's are used all throughout the industry without any reduction in power. Provided that the VFD is sized correctly it will accept single phase power and run the motor at full power.

Your first statement, not true at all, is qualified by your second. It is possible to run single phase into a VFD not designed for it and use it in a derated mode.

lg
no neat sig line

 

[Norcal]

Your first statement, not true at all, is qualified by your second. It is possible to run single phase into a VFD not designed for it and use it in a derated mode.

lg
no neat sig line

A VFD that is single phase input does not require derating. This is very common in 3 HP & smaller drives.

 

[larry_g]

A VFD that is single phase input does not require derating. This is very common in 3 HP & smaller drives.

I agree that no derating is needed for VFD's rated for single phase duty. What I am referring to is those VFD's NOT rated for single phase.

http://www.dartcontrols.com/wp-content/uploads/2012/01/De-Rating-VFD-for-Single-Phase-Power.pdf

lg
no neat sig line

 

[Bert_]

If the drive is designed for 3 phase input but only fed with single phase then the VFD has to be derated. It is common to use a drive rated 2X the size of the motor.


For small motors, like a couple HP or smaller, you can get drives designed specifically for single phase input. With those drives no derating is necessary.

The motor will produce full power in either case. the earlier post made it sound like the motor would produce less than it's rated power, which is not true.

 

[930dreamer]

Hello, any decision on you three phase power?

 

[matt_i]

Ime, you have to look carefully at the VFD and its behavior with single phase 240vac input and expecting 240vac x 3ph output. SOME have full rated HP wired as above. SOME have reduced HP as wired above. I have at least one of each out in my shop right now. Nobody can qualify either one as being rock-solid without referencing a specific model number.

Here's how I would decide. If this is likely the only 3phase machine you'll ever buy, then I'd jump on a VFD and figure out the low-voltage control wiring. Note you have to be extremely careful with a 2-speed motor which uses something like a drum switch to interchange windings. This switch cannot be flipped under power without potential damage to something.

If you are planning on filling up your shop with more 3phase-likely machinery, mill, lathe, etc, then I would build or buy a rotary converter, as it will cross over to other machines with minimal expense (basically just conduit, wiring, and wiring devices)

 

[nadogail]

Rotary Phase Converters can be cobbled together from "Bone Yard" parts.

 

[DavesGarage]

Where did the year go? Holy hell! I havent even touched the saw or 3 phase power conversion yet. I have been busy wrenching on side work and projects but the day is getting closer to needing it. Ill update when it happens...thanks a bunch guys!