3 Phase to Single Phase Re-wire - Hofmann Tire Balancer - Sanity Check

X

xjgper

Plastic

Joined

Nov 29, 2016

• Nov 29, 2016

• #1

Hello fine guys and gals. Can those with a much greater knowledge industrial machines and of the almighty angry pixie look this over? I'm attempting to add this balancer to my collection of vintage machines. late 1970's Hofmann Geodyna 44. Unfortunately, like all my other machines they need to be rewired, re-motored, or ran off a converter.

From my extremely limited knowledge of this diagram. I propose removing the 3 phase motor and replacing with a single phase 220v equivalent. This will remove L2 completely from the machine and shouldn't affect the DC braking ability (assuming that's what the diodes are for). Is this feasible?

Thanks for your time folks!
XJ

 

X

xjgper

Plastic

Joined

Nov 29, 2016

• Dec 3, 2016

• #2

Bump-a-roo

 

jlrii

Hot Rolled

Joined

Dec 17, 2007

Location

Massachusetts, USA

• Dec 3, 2016

• #3

C2 appears to bring L1 to L3 during braking to use DC braking on the the IM motor. Maybe someone else will chime in, but personally I would say no, it needs to be 3 phase. 3 phase or not God forbid C1 or C2s contacts get welded...BOOM

JR

 

TDegenhart

Diamond

Joined

Mar 26, 2011

Location

Geneva Illinois USA

• Dec 3, 2016

• #4

No, that can be rewired for single phase. If you notice, everything is wired off of L1 and L3. All you would need to do is the replace the motor with a single phase unit and you should be good to go. One issue you will have though, is the that run up time due to the inertia of the load my be more than most single phase motors can handle without being a high inertia starting motor. Good application for a repulsion start motor.

Tom

 

jlrii

Hot Rolled

Joined

Dec 17, 2007

Location

Massachusetts, USA

• Dec 4, 2016

• #5

Thanks for the correction. Does DC braking work the same for PSC motors ?

JR

 

TDegenhart

Diamond

Joined

Mar 26, 2011

Location

Geneva Illinois USA

• Dec 5, 2016

• #6

Never tried it, but I don't see any reason for not to.

Tom

 

JST

Diamond

Joined

Jun 16, 2001

Location

St Louis

• Dec 5, 2016

• #7

jlrii said:

Thanks for the correction. Does DC braking work the same for PSC motors ?

JR

Click to expand...

.
Yes. Works with any squirrel cage motor, really. A PSC is just a two winding squirrel cage motor.

Gets the rotor hot if done a lot on a short cycle. Likely not an issue with that device.

 

D

DDoug

Diamond

Joined

Oct 18, 2005

Location

NW Pa

• Dec 5, 2016

• #8

JST said:

.
Yes. Works with any squirrel cage motor, really. A PSC is just a two winding squirrel cage motor.

Gets the rotor hot if done a lot on a short cycle. Likely not an issue with that device.

Click to expand...

Well, my spin balancer...you start it up, she winds up, then takes a second or 2 to find the imbalance, then hits the brake.
1 minute (or less) from me hammering on weights, and it's run it again to re-check.

so there is several on/off cycles in a 15 minute period.

I would just hang a 4" muffin fan on it.
However, if the motor is direct drive, it may be a special, and specially balanced as well.

 

N

nickgc123

Plastic

Joined

Aug 14, 2018

• Aug 14, 2018

• #9

Help needed please

Hi there I have a hofmann geodyna 85 wheel balancer. its a three phase and have converted the motor to single phase. It has a 4 pin plug tried to work it out the pin pin cable but when connected there are no lights nothing. I disconnected L2 and used L1 live and l2 natural. but alas nothing. I know this is an old thread but hopping some one out there can help me. i have a wiring diag, it says on the motor 220/380v im trying to run on domestic 240v. I have bought this of some one the motor runs out of the machine fine but there are no lights on the machine nothing. Nick

 

Last edited: Aug 14, 2018

J

Jim Kennedy

Aluminum

Joined

Mar 16, 2008

Location

Marulan N.S.W. Australia

• Aug 15, 2018

• #10

Hi Nick,
I think your problem is you are doing what the above poster did and getting no results.
Well that Hofmann Machine is 230volts 3 phase, so if you were to change that 3 phase motor to a single phase motor and supply it 230volts single phase it should work OK.
What I am suspecting is your machine rating plate says 415volts. If so, this would mean all the internals would be 415volts, which won't work if supplied with only 240volts, but for example the old Repco machines, their circuit boards had jumpers that could be changed to 240volt position.
If you posted some pictures of your machine, the wiring diagram, machine rating plate and the machine's original 3 phase motor rating plate then this would be very helpful. Jim

 

N

nickgc123

Plastic

Joined

Aug 14, 2018

• Aug 24, 2018

• #11

Hi Jim I only have these pics on computer ill post them up and get more as soon as i can .Thank you Thank you . Your the only person on the net that has answered me to help. Nick

 

N

nickgc123

Plastic

Joined

Aug 14, 2018

• Aug 24, 2018

• #12

hope you can see these

 

Attachments

• 
  IMG_20180824_212613.jpg

  90.3 KB · Views: 941

J

Jim Kennedy

Aluminum

Joined

Mar 16, 2008

Location

Marulan N.S.W. Australia

• Aug 28, 2018

• #13

Hi Nick,
When you say you converted the motor to single phase do you mean you fitted a new single phase motor, or, you converted the existing 3 phase motor with a phase converter to run from single phase.
In post No.1 of the electrical wiring diagram, in about the center is a transformer and down the left hand side
are some terminals - 575v
420v
380v
220v
110v
0v
So that machine is connected for 220v operation if your machine has that type of transformer you will need to connect it to 220v, if you are going to run it from 240v but you still need to do something about the motor.
I am having trouble reading your posted diamgram.

Jim

 

J

john.k

Diamond

Joined

Dec 21, 2012

Location

Brisbane Qld Australia

• Aug 31, 2018

• #14

Yeah,in a nutshell its a 3 phase motor,220 or 400,still 3ph......so you cant directly run from single phase ,without a circuit to fake up at least 2 phases......in other words.....correct 1ph motor,or a capacitor setup,or a proper 3ph converter device.......