Anyone know anything about changing the 3 phase 400v motor on my new Harrison to 250v single phase?
Its got a 3 phase 1.5hp, 1400 rpm unit on at the mo. Can I simply bolt on a 240V 2hp at 3000rpm from Machine Mart?? I know a total rewire is the order
of the day but I'm prepared for that.
Am I missing something, is it dead simple or is it more complicated than I think??
Cheers,
Steve
I may be wrong, but you may want to try and get a motor that runs at the same speed.
Other than that, I think you're spot on...
I may be wrong, but you may want to try and get a motor that runs at the same speed.
Other than that, I think you're spot on...
You'd be better off fitting a 1400 rpm version, IMHO. All the gearing will then remain the same.
Watch out for direction of rotation, and check that it will fit, 1-phase motors can be bigger than equivalent 3-phase ones (the 1-phase motors have a
great big starter winding inside).
Also remember that 1-phase motors don't like to be stopped and started repeatedly - the starter winding overheats eventually.
Purely out of interest - had you considered a phase converter? Not the cheapest option, but it does mean that you can leave the lathe internals
untouched.
David
1.5HP i would buy on the net a frequency controller wich only needs 240Volts input and convert to 3phase and is able to cope with the 1.5HP then you
can change speed electronicly...
and thats a big plus!!
Tks
p.s. can a one phase be switched in dirección??
[Edited on 4/5/08 by tks]
Simple answer is NO, you will need a 4 pole motor which runs at 1400 ish the 2 pole motor run at 2850 ish machine mart do 4 pole motors as well, as has been said before how about a phase converter?
http://www.machinemart.co.uk/shop/range/guid/758758F0-FE9C-4B1C-B04E-92F2EE40584C
I'd say they do. Part number 010210100.
It's what we're going to when we get our ancient lathe running.
ATB
Simon
Thanks guys, converters for 440v 3 phase are too expensive, new motors are cheaper.
From what you all say I need a 2hp 4 pole with 19mm shaft diameter.
My L5 lathe has a clutch and a gear reverse so the motor only runs one way all the time.
Thanks,
Steve
[Edited on 4/5/08 by coozer]
this is the name plate on it ATM.
I run my L5A from a homemade rotary phase converter, runs like a dream and cost less than £20 to make. Diagrams are readily available on the net.
Al.
Originally posted by coozer
Thanks guys, converters for 440v 3 phase are too expensive, new motors are cheaper.
From what you all say I need a 2hp 4 pole with 19mm shaft diameter.
My L5 lathe has a clutch and a gear reverse so the motor only runs one way all the time.
Thanks,
Steve
[Edited on 4/5/08 by coozer]
quote:
Originally posted by Wadders
I run my L5A from a homemade rotary phase converter, runs like a dream and cost less than £20 to make. Diagrams are readily available on the net.
That motor may not be suitable for an inverter as it is stated as 440 volt only on the plate , it needs to be able to run on 220 volts connected in
delta configaration.
A 1 horse may do the job if you do not envisage any heavy use of the lathe and would be a bit cheaper and smaller so more likely to fit easily.
Paul.
quote:
Originally posted by coozer
this is the name plate on it ATM.
I don't know much about converters, I guess they are either semiconductor based, transformer based or capacitor based. If you go this way you
need to be aware that the starting current for the motor will be higher than the full load current (usually specificed as a multiple of full load
current or as locked-rotor current on the name plate) and any converter needs to be specifieded for this.
Also note the impedence of the converter will slug the starting current and run-up time but it shouldn't be too much of an issue for a motor of
this size and on this type of load. If it becomes an issue watch out for overheating - and the best way to cool an electric motor is run it on no
load, the internal fans will do the rest.
If someone has a design for a converter that you can build for £20 I would try it, otherwise buying a new motor, 4 - pole as suggested above, looks
like the best option to me. Critical mechanical dimensions for motors are usually shaft height, shaft diameter and mounting plate.
I have been quite successful using capacitors to make up the third phase. You could try some 22uF ones, someone sells decent oil cooled ones on
Ebay.
My pillar drill 3/4hp and power hacksaw 3hp both run, for the hacksaw I just needed to be able to switch in more to start. Have a google up. May only
cost you £5, you do lose a bit of power so just take smaller cuts.
Regards Mark
When I converted my lathe I was advised to use a lower horsepower motoe as that way when I cocked up I would do less damage!!
Not exactly positive thinking but valid nonetheless. professional turners want to take heavy cuts and operate all day long. Most DIY guys just make up
bushes and the odd top hat.
Another advantage of the smaller motor is its more compact. Better check space available as cheapo 1 phase motors are bulkier than 3 phase motors.
Enjoy your lathe best damn tool I ever bought