Two motor questions

[abernat]

First question. I've got a 1HP motor on my 14" bandsaw. I'm rewiring it from 110V to 220V. The current wiring didn't match the diagram - the red and black legs were swapped. From the diagram, I'm guessing red and black were opposite ends of one coil, which leads me to ask - how did this ever work? I've attached pics of the wiring diagram and the (pre-my-messing-with-it) wiring. The brown and black wires are going to "2" and white and red internal wires are going to "1" (and connected to power common). 

   

   

Second question. Assuming that the weird wiring hasn't been draining power, the 1HP bogs down when resawing (yes, I'm resawing with a 14" bandsaw - small shop woes). One obvious solution is to move to 2HP. I've attached the motor namespace pic; would this 2HP Leeson be a compatible replacement? The frame size and shaft are the same ... but not sure if I'm missing something.

https://www.electricmotorwholesale.com/LEESON-E113608/
https://www.ebay.com/itm/264330629529?ep...SwOXJexpyh

   

[Roly]

First question. I've got a 1HP motor on my 14" bandsaw. I'm rewiring it from 110V to 220V. The current wiring didn't match the diagram - the red and black legs were swapped. From the diagram, I'm guessing red and black were opposite ends of one coil, which leads me to ask - how did this ever work? I've attached pics of the wiring diagram and the (pre-my-messing-with-it) wiring. The brown and black wires are going to "2" and white and red internal wires are going to "1" (and connected to power common). 




Second question. Assuming that the weird wiring hasn't been draining power, the 1HP bogs down when resawing (yes, I'm resawing with a 14" bandsaw - small shop woes). One obvious solution is to move to 2HP. I've attached the motor namespace pic; would this 2HP Leeson be a compatible replacement? The frame size and shaft are the same ... but not sure if I'm missing something.

https://www.electricmotorwholesale.com/LEESON-E113608/
https://www.ebay.com/itm/264330629529?ep...SwOXJexpyh

Interchaning the red and black wires only reverses the motor rotation, no effect on power and only if the higher current on 120v was causing voltage drop the hp remains the same on 120 and 240 volts.    Going to the 2 hp you may have to replace the switch as the starting current will be more.   Roly

[abernat]

<pounds head on desk> it … it even says so. In text. On the label. 

Sigh…

So 2HP upgrade it is. The wiring appears to be 14ga, and if the switch (2 pole single throw) works for 1HP at 120V it should work for 2HP at 240v assuming the amperage draw is the same. So what else do I need to check for physical compatibility? RPM, frame type, shaft diameter - is that sufficient?

[Bob Vaughan]

<pounds head on desk> it … it even says so. In text. On the label. 

Sigh…

So 2HP upgrade it is. The wiring appears to be 14ga, and if the switch (2 pole single throw) works for 1HP at 120V it should work for 2HP at 240v assuming the amperage draw is the same. So what else do I need to check for physical compatibility? RPM, frame type, shaft diameter - is that sufficient?

The higher voltage will flow better through your existing wiring plus a 220 outlet is likely to have fewer things in the circuit.  It may be that the change to 220 volts is all you need.  Try that first and see.
In a perfect world, there is no difference in HP between 110 and 220 (120/240),  but the reality of existing wiring is rarely perfect.

[Roly]

<pounds head on desk> it … it even says so. In text. On the label. 

Sigh…

So 2HP upgrade it is. The wiring appears to be 14ga, and if the switch (2 pole single throw) works for 1HP at 120V it should work for 2HP at 240v assuming the amperage draw is the same. So what else do I need to check for physical compatibility? RPM, frame type, shaft diameter - is that sufficient?

 The motor running amps may be the same but starting amps will be more fore the 2 hp motor.   Roly

[TDKPE]

So what else do I need to check for physical compatibility? RPM, frame type, shaft diameter - is that sufficient?

Frame size defines most relevant parameters, including shaft diameter and keyway, shaft length (3-digit 'integral hp' frames only), location of the beginning of the finished shaft diameter to the first set of mounting foot bolt holes, bolt hole size and pattern, shaft center to mounting surface*, but frame size says nothing about terminal box location, or motor length, etc.  Fortunately, most of the undefined dimensions don't usually matter unless it's in a tight space.

So if they're both NEMA 56 frame motors, the shaft is 3.5" up from the foot surface, 5/8" diameter and keyed, starting 2-3/4" from the first bolt holes, etc (see NEMA frame table link below).  They should be interchangeable unless the terminal box, if on the outside rather than inside the end bell, is in the wrong place.  

One caveat is that if the frame size has a "Z" at the end, the shaft is non-standard.  The Z says nothing about what makes it non-standard, though, so if it's there, it could be shaft length, diameter, or even just the presence of a tapped hole in the end.  

* two-digit frame size is sixteenths of an inch, three-digit is quarters of an inch for the first two digits

http://www.kellerelectrical.com/pdf/NEMA...rt_KEI.pdf

Edit: Almost forgot - as already suggested, do try 240V connection first. If the tool is at the end of a long wire run, voltage drop can make it seem weaker than it really is, as the torque curve drops as the square of the actual to design voltage ratio. A little voltage drop makes a tool feel a lot weaker than it would on a stiff supply, and doubling the supply voltage while halving the current (in the same size and length of supply wiring) keeps that torque curve up where it should be. But do be conscious of the fact that you're working it well beyond its continuous output rating, or current rating if the voltage is drooping under load, when you're pushing it so hard it starts to bog or slow noticeably. Do give it some run time without cutting to cool back down, even if it's running on the higher voltage.

[jteneyck]

You will notice a decided benefit from the 2 HP motor on your saw.  You will actually be able to resaw something in one calendar day.  Put a 1/2" x 3 tpi blade on it and enjoy.    

John

[TDKPE]

You will notice a decided benefit from the 2 HP motor on your saw.  You will actually be able to resaw something in one calendar day.  Put a 1/2" x 3 tpi blade on it and enjoy.    

John

And to that end, at one point Delta offered a 2 hp on the 14" BS.  Model 28-241F and G (single- and 3-phase) in the 2002-2003 catalog, though I don't know how many years that was offered.

[abernat]

Edit: Almost forgot - as already suggested, do try 240V connection first.  If the tool is at the end of a long wire run, voltage drop can make it seem weaker than it really is, as the torque curve drops as the square of the actual to design voltage ratio.  A little voltage drop makes a tool feel a lot weaker than it would on a stiff supply, and doubling the supply voltage while halving the current (in the same size and length of supply wiring) keeps that torque curve up where it should be.  But do be conscious of the fact that you're working it well beyond its continuous output rating, or current rating if the voltage is drooping under load, when you're pushing it so hard it starts to bog or slow noticeably.  Do give it some run time without cutting to cool back down, even if it's running on the higher voltage.

Oh really... sure, that makes it worth experimenting. The 120V line in my garage comes from the other side of the house (12 gauge wire, but also feeds the lights + chest freezer), and the 240V is off a subpanel I had added. I do need to move the rest of the circuits over... 

I'm getting 123V without the bandsaw running. The circuit is ~80 feet and some random online calculator says I should expect a 10% voltage drop with a 10A draw. So sure - I'll rewire and see what happens.

[TDKPE]

I'm getting 123V without the bandsaw running. The circuit is ~80 feet and some random online calculator says I should expect a 10% voltage drop with a 10A draw. So sure - I'll rewire and see what happens.

10A over 160 ft out and back at 2 ohms/1000 ft for 12-gauge copper wire is only 3.2V dropped in the wiring.  You’re starting at 123V with no load, so you’d have 120V under load, which is still higher than the nameplate voltage of 115V.  Other than a little stronger start-up, I doubt you’d see any performance difference.  Even pushed to bogging, where the current is higher than at rated output resulting in more voltage drop, the motor is still going to see no less than nameplate (design) voltage.  

I’d give it a try anyway, but I’d also start shopping for a good resaw blade, and keep my eyes open for a stronger motor.