Problem with phase converter.

[guypowerup2]

Good Morning Folks. Have a question regarding a "used" Phase-A-Matic RPC model R-7 coupled with a VS-7 Stabilizer. I am concerned about the output voltage on the "manufactured" leg. When the converter was energized, My Voltage readings were as follows:
L-1 (utility) 123.1 Volts
L-2 (utility 123.9 Volts
L-3 (from Phase converter) 201.0 Volts
L-1 to L-2 234 Volts
L-1 to L-3 246 Volts
L-2 to L-3 240 Volts

The readings were taken to earth ground and also to the system's Neutral......measurements were identical. The motor nameplate (an old Bridgeport Drill Press) on the Motor Lists: 220 Volt, 230V and 440V. I am concerned about powering up the drill press due to the 201 Volt on the Manufactured Leg. The Press Motor is currently configured for 230 Volts.
The Phase converter is listed as a 220 volt model. I am concerned about the 201 Volt actual Output. I believe I read somewhere that there is a NEMA suggestion of not exceeding 10% plus/minus with power supply versus the motor's name plate rating. At 201 volt output, I am 7 volts below the minimum at 230 volts and Barley at the minimum if I rewire the motor to 220 volts.

Any Suggestions/Thoughts/Ideas?

Thank You!

Guy

 

[hillbilly1]

Unless your motor uses a neutral, it doesn’t care about the voltage to ground. (Unless it has a frequency drive)

 

[ptonsparky]

Load it up and the voltages may even out a bit.
Generated Phase to G or N means nothing.
The motor does not care other than it has a reasonable L-L voltage. YMMV.

 

[guypowerup2]

Thank You for the reply! There is no neutral involved and no VFD involved. My concern is the 201 volt on the phase converter's output causing the motor to overheat.

 

[guypowerup2]

Load it up and the voltages may even out a bit.
Generated Phase to G or N means nothing.
The motor does not care other than it has a reasonable L-L voltage. YMMV.

Thank You Sir! I will give it a try tomorrow and let you know how things go.
Take Care!
Guy

 

[LarryFine]

I am concerned about powering up the drill press due to the 201 Volt on the Manufactured Leg.

Don't be. A rotary converter creates a high-leg delta.

Your load only sees the line-to-line voltages.

 

[hillbilly1]

One word of caution though, do not use the generated leg for control power regardless if it is 230 volts.

 

[guypowerup2]

10/4 thank you.

 

[Little Bill]

I wired one up for some woodworking equipment. The instructions said not to connect the high leg to a certain terminal in the wiring compartment. That terminal was for 120V control. It was clearly identified, and you know which leg/wire is high, so you don't connect the high leg there. If no 120V is required, it doesn't matter where the high leg goes.

 

[hillbilly1]

I wired one up for some woodworking equipment. The instructions said not to connect the high leg to a certain terminal in the wiring compartment. That terminal was for 120V control. It was clearly identified, and you know which leg/wire is high, so you don't connect the high leg there. If no 120V is required, it doesn't matter where the high leg goes.

The last couple I hooked up said not to use the high leg for the controls even though it was a 230 to 24 transformer. Apparently something about that leg was not stable enough.

 

[ptonsparky]

It's kind of hard to start things up with a control voltage that isn't there, until it's running.

 

[guypowerup2]

Hey Folks......Thank You so Much for your Help!
I checked out the control wiring to make sure the "manufactured" RPC leg wouldn't be powering the 230 volt coil on the starter. Fired up the converter and Drill Press worked perfectly! Again...thanks for the Input.
God Bless and Be Safe.
Guy

 

[Jraef]

It's kind of hard to start things up with a control voltage that isn't there, until it's running.

Where there's a will, there's a way...

I had a guy "fix" that problem by manually pushing in the contactor plunger. He even made a special stick for that purpose and of course, took the door off of the enclosure to be able to get the stick in there. The RPC cabinet was full of sawdust, some of it burned.

 

[ptonsparky]

I put PLC controls on a MMC and kept finding short pieces of lath or shims. The operator teased me later about the look on my face when it finally dawned on me.

 

[guypowerup2]

I get it! I'm trying to "retire". Sixty Seven and feeling old. Tired of dealing with people that are EVEN dumber than me! Owned my own Electrical Contracting Business for 38 years. Did mostly Residential and Commercial. I've set up a bunch of NEW 3 Phase Services, Motor Starters, Grain Dryers etc.....but I just don't know about the "fine" points of motors and transformers....and quite frankly...I'm too old to learn and would rather spend time with my grandkids and GREAT grandkids.

God Bless you All!
Guy