how easy is it to convert 3 phase machines into 240v???

[cornish wood burner]

I have wondered the same for years but still can't imagine how a great big 3 phase motor could run off a 13amp plug no matter what magic the electronics in the middle can offer.

 

There must be a hp/Kw cap under which the magic can work?

 

You cannot run big motors off a 13 A plug. There are 16 and 32 A ones available if you go that route.

5 hp motor would need a 32 A circuit and plug and socket, or wire in direct and create a 3 phase circuit with multiple outlets if required.

[Marko]

Thanks for that. Does this mean that 3 phase is now unnecessary / outdated? If not, are there good reasons for still specifying three phase.

[cornish wood burner]

Thanks for that. Does this mean that 3 phase is now unnecessary / outdated? If not, are there good reasons for still specifying three phase.

 

Main reason I can suggest for specifying a 3 phase supply, is your supply company will maintain your supply, rather than you having to replace your conversion box when it fails. Depends how much 3 phase you are planning to use and the installation cost.

[Peter]

Thanks for that. Does this mean that 3 phase is now unnecessary / outdated? If not, are there good reasons for still specifying three phase.

 

 

Not at all, if you're running a lot of 3 phase machines then running multiple phase converters gets expensive.

 

If you're going down the phase converter route I would go digital rather than rotary.

[Ilnumero]

You are better off swapping the motor for a single-phase one. Cheaper than buying a phase converter and the associated wiring for it.

 

Have a look here - MM Engineering Services |

[roys]

As Robbo90 I used Drives Direct to buy a converter.to run my 3 phase Colchester Master lathe, works a treat.

I used to use a rotary converter to generate my 3 phase, but these are inefficient and noisy, the electronic unit is much better on my failing ears.

[Mike Dempsey]

If you are going to buy a 240v single phase motor to replace a 3 phase motor you are also either going to have to buy a new contactor or a 240v coil for the 3 phase contactor that started up the 3 phase motor. I have converted many 3 phase machines in my workshop to single phase over the years. My mate runs an industrial sparkies business and also a motor rewind company. Very good for free advice and also second hand motors as well. Some of the older machines had imperial sizes for the mounting hole psitions and also the shafts. Motors with imperial fittings are still available. Getting one of these will also save you having to buy a new pulley or getting the pulley bored out to fit the spindle. For things like lathes the best way to convert it is to buy an inverter, which will then give you variable speed by just turning a dial.

[se7enthdevil]

i should point out that i will not be doing any of the converting myself. i know nothing about electrics nor do i wish to. it's dangerous stuff so i leave it up to the people who know what they are doing.

 

i merely wished to find out if it's tricky or impossible or if in fact it may be something that could be done relatively simply.

 

this item would be going in my workshop at the bottom of the garden and i only have 240v.

 

 

K66 LOG, i will not walk away as it is what i've been looking for to help me do a particular commision i've just received. it's just up the road from me so i will be checking it out before i buy (i'm definitely not looking to pay what he's asking) but if it's falling apart at the seams then i'll leave it there.

[se7enthdevil]

If you are going to buy a 240v single phase motor to replace a 3 phase motor you are also either going to have to buy a new contactor or a 240v coil for the 3 phase contactor that started up the 3 phase motor. I have converted many 3 phase machines in my workshop to single phase over the years. My mate runs an industrial sparkies business and also a motor rewind company. Very good for free advice and also second hand motors as well. Some of the older machines had imperial sizes for the mounting hole psitions and also the shafts. Motors with imperial fittings are still available. Getting one of these will also save you having to buy a new pulley or getting the pulley bored out to fit the spindle. For things like lathes the best way to convert it is to buy an inverter, which will then give you variable speed by just turning a dial.

 

 

 

if i end up buying this machine i may well be after some advice so thanks.