First time here? Do you sell to woodworkers? Need help? Ask Woody!
Accounts
Home Articles Forums Gallery Marketplace Videos
Premium Domestic, Figured & Live Edge Hardwoods in Stock. Best Prices for Serious Woodworkers.

WoodCentral Forums

Knowledge You Can Build On — Est. 1998

PM3520 wiring

Posts

PM3520 wiring

#1

PM3520 wiring

Bob Strand

>I've got a PM 3520 and every time I turn it on I get bad radio static. I thought it was wiring problem in the shop, a friend and I did it, but come to find out the PM has a 3 phase motor and I've only got single phase wiring into my shop. Can't get 3 phase as I'd have to run a new line, pole and transformer about 2 miles worth. I'm told running it like is will reduce the efficiency and longevity of the motor. Has anyone had this problem and what am I up against?

I'll call PM in the morning but I've found in the past how valuable the opinions of this site are.

Thanks,

Bob in 22 below Ft. Peck, MT

Re: PM3520 wiring

#2

Re: PM3520 wiring

John Albachten

>Bob-

I have the same lathe (I am very pleased with it) and it is indeed a three phase motor but it has a built in phase converter and is designed to run on single phase current. The interference with some electronis devices is a problem - I believe filters are available or can be built but I found it easier to just move my radio further from the lathe and the problem went away.

You definetly do not need to run three phase power to your shop!

Enjoy your new lathe and good luck!

-John

Re: PM3520 wiring

#3

Re: PM3520 wiring *LINK*

Robert Cox

>Does this help?


Down the page a bit

Re: PM3520 wiring

#4

Re: PM3520 wiring

Bob Strand

>Thanks much for the info on the 3520 wiring. I'll check on a filter in the morning.

Having a heat wave up here, its almost up to zero

Re: PM3520 wiring

#5

Re: PM3520 wiring

Bill Howatt

>what you are up against is a case of radio interference and the link given to a thread about the Oneway RFI filter should cure it if it works as others described.

Yes, your lathe has a 3 phase motor but it has an electronic single-phase to 3 phase converter and it is from that device your radio noise is coming from. It is switching relatively high-currents very quickly and this is the basis of radio waves.

This device not only converts single phase to 3 phase but converts it to variable frequency 3 phase. The speed of an induction type electric motor is determined by the frequency of power and other motor characteristics. By changing the frequency of the power to motor they are able to provide you with that very nice "turn of the knob" speed control.

Any concerns about running the motor on single phase is invalid since it is running on 3 phase.

Bill

Re: PM3520 wiring

#6

Re: PM3520 wiring

johnd

>I think you will find it is variable voltage rather than frequency.

Re: PM3520 wiring

#7

Re: PM3520 wiring

RP

>I am pretty sure PM varies the frequency and keeps the voltage steady. This keeps the amps/volts up and gives the good torque up at low speeds.

Re: PM3520 wiring

#8

Nope

Bill Howatt

>Changing the voltage on an induction motor does virtually nothing to change the speed until the motor rotor starts "slipping" in the rotating field. At this point, the torque dramatically drops off and you can burn out the motor.

The one factor that determines the speed of an induction motor that can be varied is the speed of the rotating field inside the motor that the rotor locks onto. The way to vary this is by changing the frequency.

Changing the applied voltage does work for DC motors.

Bill

× Share

Share on

X / Twitter Facebook LinkedIn
✉ Email this page