Running 3-phase gear off single-phase power.

**Sheppie** · 13th February 2013, 08:20 AM

[QUOTE=DoubleChevron;1854253]I think a lot of old farms have this. It's not true 3phase. One of my mates has it on his farm. You can get away with far less current pull using "two phase". I pretty sure the phases are 180degrees apart... they must be the two sides off a center tapped trannie (I'm sure google would give the answer in seconds if you searched). I've seen old 240volt motors that have wiring instructions/tappings for 2phase.

I made myself a phase converter for a big grinder a while back. You need to have the correct 3phase motors. They need to be wired delta @ 240 across the phases from memory (check that, don't trust my memory). It worked ok, I just pull started the 2nd motor with a rope around it's pulley. Using cap start too run the 3phase motor ... it just didn't sound happy.

Honestly though?? 3hp motors are cheap in single phase these days .... it's probably going to be cheaper and less hassle just to by the single phase motor to suite. I did miss out on a 5hp single phase (monster sized ancient job) at the closedown of a motor rewinders a couple of years back. I'm still kicking myself for not grabbing it. Imagine the compressor I could run with that

I'd have to switch off everything in the shed to start it though .... could you imagine the startup current pulled by a 5hp motor

The compressor used to dim half the street with a 3hp motor.

I have a brand new 5HP single phase motor if anyone wants it.
I was going to put it on my car hoist but I moved and now have 3 phase power

Love it.
Anyway, the 5HP is for sale if anyone is interested. I paid $700 for it.
Make an offer. A realistic one please.
on another note, 3hp (2.1kW) VSD's are pretty good, Ive got one of these as well. Having frequency speed control beats changing belt configuration every time you want to slow down or speed up your lathe. Its not used anymore since im now on 3 phase.
Cheers,
Phil

**wrinklearthur** · 13th February 2013, 01:32 PM

I'm a bit vague on how it was done, the fitter and turner not far from me has a thumping big lathe in his shed and only has single phase to the shed.

Noting this, I asked him how did he run it?

Well, he went over and checked all was clear, then turned a key, a engine started and then using a automatic shifter, selected a forward gear and away the lathe rotated.

The power source is a old Cortina and he has permanently set the car up next to the shed and drives the gear inside with a shaft connected to the back axle.

It's impressive way to get around the problem, but it did cost him a new car for his wife at the time, less an amount for a no trade in deal.

.

**rovercare** · 13th February 2013, 03:21 PM

Originally Posted by wrinklearthur

I'm a bit vague on how it was done, the fitter and turner not far from me has a thumping big lathe in his shed and only has single phase to the shed.

Noting this, I asked him how did he run it?

Well, he went over and checked all was clear, then turned a key, a engine started and then using a automatic shifter, selected a forward gear and away the lathe rotated.

The power source is a old Cortina and he has permanently set the car up next to the shed and drives the gear inside with a shaft connected to the back axle.

It's impressive way to get around the problem, but it did cost him a new car for his wife at the time, less an amount for a no trade in deal.

.

I was at an old dairy the other day, still had the functional pro input for the milk pump for power outages

**Vern** · 13th February 2013, 04:59 PM

Geoff 'junior' hallidays dairy I presume. I seen that as well a while back. You must have been fixing the job I couldn't get to.

**Blknight.aus** · 13th February 2013, 06:25 PM

Originally Posted by rovercare

I was at an old dairy the other day, still had the functional pro input for the milk pump for power outages

Pro or PTO?

**rovercare** · 13th February 2013, 07:15 PM

Originally Posted by Blknight.aus

Pro or PTO?

PTO

On a phone, just back from monash with surgery on the newborn young fella, so proof reading hardly took priority

**rovercare** · 13th February 2013, 07:16 PM

Originally Posted by Vern

Geoff 'junior' hallidays dairy I presume. I seen that as well a while back. You must have been fixing the job I couldn't get to.

Yes

**steveG** · 13th February 2013, 09:27 PM

Originally Posted by rovercare

PTO

On a phone, just back from monash with surgery on the newborn young fella, so proof reading hardly took priority

That's not too good Matt - hope he's doing OK.

Steve

**rovercare** · 13th February 2013, 09:55 PM

Originally Posted by steveG

That's not too good Matt - hope he's doing OK.

Steve

All is good now, discharged back home etc, wife went through a bit. 3 months of terrible pelvic instability, 12 hrs labour the emergency c section, then off to monash to get his nuts fixed up! No more breeding, I'll be off to see the surgeon and have mine fixed up soon

9 pound 14 ounces out of a girl that's normally 54kg ringing wet is an ask

**wrinklearthur** · 13th February 2013, 11:13 PM

Originally Posted by rovercare

All is good now, discharged back home etc, wife went through a bit. 3 months of terrible pelvic instability, 12 hrs labour the emergency c section, then off to monash to get his nuts fixed up! No more breeding, I'll be off to see the surgeon and have mine fixed up soon

9 pound 14 ounces out of a girl that's normally 54kg ringing wet is an ask

Ouch! poor mum, hope all are doing better now.
.

Thread: Running 3-phase gear off single-phase power.

Thread Tools

Cortina convertor

torrid time

Bookmarks

Bookmarks

Posting Permissions