230 volt motor wiring ....

[Woody]

Hi,

I've been reading the electrical threads here with great interest. But I have 2 silly questions...

Question 1

I've bought a 115/230 volt motor for my bandsaw. I've been told to wire it with 230 volts. The diagram on the motor shows that "line 1" connects with certain wires, and "line 2" connects with others.

The problem is, what happens to the Neutral (white) wire ? Is there no white wire, when setting up for 230 volt installations ?

By the way, which is "line 1" -- the black or red wire coming from the panel ? Or does it matter ?.

Question 2 : Should I forget the 230 volt business, and just wire it to 115v, but use a 20 amp breaker ? Will this degrade the performance of the motor in any way ?

Thanks !
Woody.

[J.P.Rap Hamilton]

Hi Woody
You only need two wires for 230 volts Red and Black.If you connect black and white , and red and white you'll have two 115 volt lines.
You will not affect the motor performance with proper wireing for either.I always use black for L1, it's just habbit, I don't think it matters.
J.P.

[Mike Harris]

Hi Woody,

1.First you need to wire the motor at your bandsaw, use #12/3 type SJOOW cabtyre (its moisture resisant),don't use your existing cord as its only rated for 15 amps, #12/3 will due if you want to run it on 120V.L1 is black, L2 is white and Green is ground.Follow the wiring diagram on back the cover plate.
2.Next use a male cord cap rated 240V@15amps, this prevent someone from plugging in a 120V device.
3.Wiring back to your panel: These days Red jacketed #12/2NMD90 is used for 240V circuits @ 20 amps but I would use White jacketed #12/2NMD90 for the simple reason that you can use it for 120V or 240V circuits, #12 will handle the current rating of your motor at 120V.
4.The receptacle needs to be rated at 240V/15amps, normally they're only avaliable as a single.
5.Breaker or Fuse panel: For breaker use a 2-POLE 15 amp, for a fuse panel use 2 15A fuses screwed into cartiage that plugs into the panel(I forget the trade name for this, before my time).

You probably know most of this but sometimes its easier just to spell it out.

Hope this helps
Mike

[Mike Harris]

Missed a couple of your ?'s, there is no neutral in a 240V circuit and it is said that motors run more efficiently on higher voltages. I'm not sure I agree with that statement but higher voltages draw less current lower draw more.The decision is yours to go 120 or 240V.If you don't have room for 2-pole breaker in your panel, then go 120V.

Mike

[Ron Evers, Beeton, ON]

Woody, the 230V is between the black and red and it does not mater, which you use for lead 1 or 2.

You have not said what size the motor is (what amperage it draws at the different voltages). This is very important if you choose to run it at 120V. If it draws more than 12A @ 120 you will need to upgrade from standard household wire size of 14 gauge.

Best Regards, Ron.

[Mike Harris]

From his previous post he was looking at 1.5hp motor so I assumed 18/9amp @ 240/120V.

[Mike Harris]

[Steve in Kemptville, On.]

Please correct if I'm wrong but... I don't think he'll need to re-wire the motor as long as he goes 230v (with the 1.5hp motor). If the existing cable is CSA approved I think it will be good for 120 or 230v service in which case the 230v will draw under 10 amps, ok for a 15amp cord.

[Mike Harris]

We're still assuming its a 1.5hp motor, wth being a dual voltage motor the wiring has to rated to handle the higher current even if used on 240V.(ie: 18A@120V)

[Steve in Kemptville, ON]

[Gary in Niagara]

The way I understant the advantage for the higher voltage is lower amperage...lower amperage = lighter guage wire and less heat...less heat = motor last longer.

[Mike Harris]

We could get into a debate but the heat created is same P=ExI P=ExI

=240x9 =120x18

=2160Watts =2160Watts
This is true power and doesn't apply in AC motors as they are inductive loads but it serves good example.Maybe the Electrical Engineer in the crowd can help(Randy), I'm just an electrician and trade school was along time ago. Do motors run more efficiently on higher voltages, does it have something to do with losses ie: windage and rotational losses?

Mike

[J.P.Rap Hamilton]

I wouldn't dare argue the point,I'm just passing along the info I got.
I picked up a motor (free) as a spare in case I needed it.I took it to the folks who repair our motors for us(at work) to ask there opinion of the quality of the motor.I also inquired about the dual voltage. I was told it made no differance in efficiancy or draw and only a slight differance in the startup.I know little about motors but these guy are experts and I respect there opinion.
J.P.

[Woody]

[Mike Harris]