Anyone know how to rewire a 3 phase motor, 440v -> 240v?

[silangdon]

I've been gifted a lathe and have found an ebay vendor for 3 phase inverters, however I need to rewire the motor. It does take 240v according to the information plate (I've put some pics up here..):

http://zardoz.no-ip.biz/

I guess the three bridged terminals are the 240v ones. The three input wires are identically brown. Does it matter which one goes where? Should I bridge the 440v terminals when I'm done?

Thanks

 

[Spark123]

The bridged terminals will be the star point, not the 240v. The 3 brown wires are the 3 phases, you do not need a neutral in a 3 phase motor. It may be marked up as 240v as it can be connected in 3 phase 240v in another configuration.
From your 415v inverter you need to connect one brown to L1 (or however the 1st output is marked), the next brown to L2 and the 3rd brown to L3. Earth the metal casing of the motor. If it spins backwards, swop any of the 2 brown wires over at one end.
Another other option is to source a 240v single phase motor.

 

[silangdon]

It may be marked up as 240v as it can be connected in 3 phase 240v in another configuration.

That's the configuration I'm after. My ebay man is getting me a converter (may have had my terminology wrong..) to supply 240 x 3 phase from household mains; 440v 3 phase inverter / converters are loads more expensive

Thanks

 

[Spark123]

The motor can be wired as delta, often denoted by a triangle on it. Is there any diagrams on the motor, any markings on the terminals i.e. U1 V1 W1 U2 V2 W2?

 

[conny]

If you are still trying to run this motor from 240v then you must identify U1, V1,W1 and U2, V2, W2.
You then connect U1 to V2, V1 to W2 and W1 to U2.

U1-V2=phase line.
V1-W2=phase line.
W1-U2=phase line.

All phase lines must be 240v so these must be tested with a voltmeter/multimeter set accordingly. To test what voltage you have place your probes on U1 and V1, then V1 and W1, then W1 and U1. If it reads 415v or anything in that region then leave the terminal block as it is, you have a 415v supply 3 phase not 240v 3 phase.

Just curious, where are you taking your supply from?

 

[JACKC]

An inverter will give out approx 200v across phases. You will need to connect the motor in delta for it to work from the inverter. On the data plate it will hopefully have a Y (star) with 400v - 440v next to it and a triangle which is the delta sign and 200v - 240v next to it. If you have this on the plate then it will run off the inverter. The 3 shorting links will need to be fitted in 3 straight lines from left to right to connect motor in delta, if the run across all 3 terminal links they are in star.

 

[Spark123]

Wasn't a normal motor termination;

The only way I can see the bars fitting is the long one dropping down connecting 1-6, the 2 short ones going between 2-3, 4-5. Would have to test before connecting it though to ensure that is right!
Saying that, the OP was back in April so has probably got it done and forgotten about us by now