Motor Wiring Gurus, could you have a look?

[M. A. Espinoza]

Got a new motor for the bandsaw and hoping to get some guide to wiring. I've done some wiring but not an electrician by a long shot.

Unfortunately even though this is a Baldor motor they build it for a manufacturer so tech help isn't readily available.

So if anyone out there is good with electrons could you look at the diagram and give me some pointers as to wiring for simple woodworking application.

Motors are pretty simple but I don't want to trash my new motor by doing trial and error.

Just want to wire it up either 110 or 220 (probably 220, higher amp draw than I thought) to an appropriate on/off switch. The diagram shows 3PDT switch and not what I planned on using.

Thanks for any help.

-Mario

[Dale Lesak]

If you go with 220 you should use at least a DPST switch. that way both load lines would be open when the switch is off.

[mike wacker]

Mario,

With the utmost respect, looking at your post and the wording, I would recommend you either enlist the aid of an electrically savy friend or hire an electrician.

Mike

[Tom Veatch]

.... The diagram shows 3PDT switch and not what I planned on using.
...


I notice that the data plate shows the motor as being "Gate Duty". The 3PDT switch shown in the diagram is needed to reverse the rotation of the motor for opening and closing a gate. If you are using it for a bandsaw, there's no need for the switch. Simiply connect the leads according to the switch position shown for CCW rotation and for the opposite switch position for CW rotation. I suspect that the CCW rotation is what you want - at least it would be on my bandsaw.

Your on-off switch will switch the leads labeled "Line A" and "Line B". According to code, you can use an SP switch to make and break only one of the hot leads. But, understand that if you do that, one lead will always be hot even when the switch is in the off position. Use a DP switch. They are a little more expensive, but my personal prejudice is to always switch any line that isn't at ground potential.

[Jim O'Dell]

Probably more expensive, but could you use a 220 volt contactor that has a 110 trigger and use a normal single pole switch to run it? It makes sense in my head, but I don't want to put it out there as fact. Jim.

[Rob Will]

I would go to the local electric motor shop and get a magnetic starter factory mounted in a housing with built-in push buttons.

Definitely go 230V on anything over 3/4 hp (JMHO).

There are a lot of reasons to use a magnetic starter here.

Rob

[Pete Bradley]

I agree with the folks recommending starters, but I believe your real question is what wires go where? The wiring diagram you got from Baldor contains this information, but as Tom recognized, they've provided a diagram for a gate setup (OPEN-STOP-CLOSE). All is not lost. A 3PST switch operates like this:

http://www.musicgearsource.com/images/3pdt2.jpg
You only need one direction. One (extremely cheesy) option would be to get a 3-phase starter and simply wire it up like the top or bottom half of the switch in your diagram. The right thing to do is to trace half the diagram back to line A and B to get it down to two wires.

I'm not sure what your experience level is so I'll remind you that this is nothing to fool around with. A mistake could damage your motor or injure or kill you. You must run a ground from the plug to the machine and the motor. Electrical posts on forums like this attract bad advice like a magnet. An electric motor shop could help, and a licensed electrician might well be the best approach.

Pete

[M. A. Espinoza]

Thanks all.

Its making more sense now. I've wired up some motors and simple switches in the shop and at work. But I've been able to follow exact diagrams per the application.

Here mainly I'm concerned about which wires to tie together and what to ground.

The 3PDT now makes sense as it is a gate motor and you would want to reverse it, I don't need this obviously.

I was planning on using a DPST of some sort.

Some have suggested a mag start, why is this? I'll spring for one but I know there are a lot of 1.5hp tools out there that don't use them.

I guess what I need to do is just look at a scheme for a DPST wired 220.

I'm very aware of the importance of proper grounds and am being cautious to protect the motor and anyone that might use the tool. However we are talking about a few connections here; should be pretty simple once I figure out which wire is which.

[Jim O'Dell]

The magnetic starter is so that if power is lost while using it, when the power comes back on, the motor doesn't. It is just a safety thing. Jim.

[Tom Veatch]

...
Here mainly I'm concerned about which wires to tie together and what to ground.
....

For 220V CCW rotation:
1-Line A
2-3-6-7
4-5-Line B

For 220V CW rotation exchange lead 5 with leads 6 & 7

For this application, leads 6 & 7 are not both needed. One of the two could be capped off and not used. Alternately they could be connected together and treated as a single lead.

If the "optional thermostat" isn't installed, you might want to consider using a magnetic starter sized for the motor amperage/HP to provide overcurrent/overtemp protection.

Since both Line A and Line B are "hot" relative to ground, none of the leads should be grounded. The motor enclosure can/should be connected to the equipment grounding wire (green wire).

[Tom Veatch]

Probably more expensive, but could you use a 220 volt contactor that has a 110 trigger and use a normal single pole switch to run it? It makes sense in my head, but I don't want to put it out there as fact. Jim.

That is certainly an option. And if the contactor is wired to be self latching you can have a "magnetic switch" by using two momentary switches for on/off functions. That will not provide overtemp/overcurrent protection for the motor like that provided by a "magnetic starter" but would prevent the motor from restarting when power resumes after an outage.

[M. A. Espinoza]

Thanks, crystal clear.

I knew this would be easy for someone, but out of my arena and I really didn't want to kill the motor or worse.

Much appreciated.

[Rod Sheridan]

Mario, this is a gate duty motor, meant to run for a short period if time, such as a few minutes, every half hour or so. (You would have to check with Baldor to determine exactly what the time frames are).

This motor may not be suitable at all for woodworking machinery.

Regards, Rod.

[M. A. Espinoza]

Rod,

I'll look into that. I was going by the service factor and my saw was originally a 3/4hp so I thought I was going pretty far beyond what it called for.

I'll confirm with Baldor on gate duty, I had just checked around on the web and it seemed gate duty was a heavier service motor.

But thanks, I'll make sure I'm not going to overload the motor.

[Tom Veatch]

Rod,

I'll look into that. I was going by the service factor and my saw was originally a 3/4hp so I thought I was going pretty far beyond what it called for.

I'll confirm with Baldor on gate duty, I had just checked around on the web and it seemed gate duty was a heavier service motor.

But thanks, I'll make sure I'm not going to overload the motor.

Just my opinion, so take it for whatever it might be worth, but I think you're ok with that motor for your application. But, Baldor would be the best source for definitive information.

I'm not sure "Gate Duty" is a recognized NEMA rating, but I'm open to correction on that. The data plate on the motor has the "Gate Duty" notation in the block for power. The "Rating" block seems to indicate the motor is rated for continuous duty. You can't really bet the farm on that since there seems to be a lot of looseness in the layout of data plates from different manufacturers.

I will say the motors used on the vehicle gates at my "pre-retirement" place of employment got a severe workout. Start/stop cycles were far more frequent than any motor - even a dust collector motor - would ever see in my shop.