Motor mounting position

JTknives

JTknives

Blade Heat Treating www.jarodtodd.com
Joined
Jun 11, 2006
Messages
8,630
I just picked up a 25hp 3ph motor that is new and strapped to a pallet. I got it for a song and did not even notice that it was footless. It’s a C face mount only which normaly is ok but this motor weighs 450lbs. It’s going to be phase converter for the 10 press so it just need a simple base. My question is can it be mounted verticle. I find conflicting answers to this in my research. Some people say only small motors can be and others say yes but only if it’s designed for it. It uses deep groove ball bearings but don’t know if those can take it. My thought was to stand it up on a plate with the shaft facing down and mount the pony motor the same way and then belt them togather. But I don’t want to be replacing bearings in a month on a brand new motor. Or I could just make a wooden cradle for it to sit in and mount a bracket to the c face to hold the 1.5hp pony.

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I'd contact Toshiba and ask them. I've seen large motors mounted vertically on pumps so they do make motors which can be mounted vertically, just don't know if this one is one of them.

Could you clarify how you plan on using the motor for a phase convertet? Motor generator?
Jim A.
 
You should be able to find the axial load limit for the bearings. If the stator and shaft assembly isn't over that, vertical should be fine.

D DAMNENG he's probably doing the same thing I am (other than using a pony motor instead of capacitors to start) which is spinning the 3 phase motor with 2 phases of power and then tapping all 3 to supply a sub panel.
 
It’s a bit complicated but I will try and explain it the best I can (not an expert). You feed 230 single phase into 2 of the lines in on the 3 phase motor. You get the motor spun up close to sync rpm and flip the power up. The moter will run on single phase. Now 3 phase use 3 wires and the motor is just being powered off 2 right now. The moter as it’s idling is acting like a generator and generating power in the 3 leg. You now can wire any other 3 phase motor up to this idler motor and it will run perfectly fine. Now if you want to get picky and save power cost you add in balancing capacitors between the phase lines L1,L2 and L3. This adjusts the voltage of the ghost leg up to the voltage of the others. You use capacitors to increase the power factor. Low power factor increases the amount of power you use and are charged for so a few dollars in capacitors goes along way. This is why I have a 7.5hp rotary phase converter as well. I don’t want to run the 25hp all the time becaus it’s idle amp draw on single phase is rather high at around 30 Amps. Now this is unbalanced and will get much lower once I install the capacitors. I use the 7.5hp on the surface grinder.

Basically in a bit shell your using a 3 phase motor as a rotating field transformer. Guess I could have just said that above lol, oh well it’s late.
 
easiest would be a cradle arrangement then you don't have to worry about stress on other components. put 4 locking wheels on bottom of cradle so it is easy to move.
 
I agree, make a cradle with a metal base plate and two upright arms drilled for the C-face. The same base cam have the pony motor mounted on it.
 
I ask because it doesn't look like a "c" face motor, it looks like a pump base flange for vertical mounting to shafting. Under the straps and cardboard, I suspect you will find heavy cast iron bolts holes for the lifting hooks usually used to rig the pump out.

Just a guess, i could be wrong here.
 
Just leave it strapped to the pallet. ;)

In all seriousness, since it's not going to pulling any major torque, you could likely do just about anything for a base frame. There's probably some holes already tapped for some kind of base plate. Just weld something up that will take the starting torque of the motor.
 
A lot of IEC (metric) motors have the facility to mount feet in different locations, so that the terminal box can be clocked to the left, right or top. I'm not really familiar with NEMA-frame motors.

It looks like the pads for mounting the feet are every 90 degrees on that motor, offset at 45 degrees to the terminal box. If so, you'll have the option of either buying the manufacturers feet or of cobbling something together yourself. The latter is likely to be cheap and easy, as you don't need to worry about loads imposed by a drive capable of handling 25 HP when using it as an idler for an RPC.

Get the strapping off and see what's underneath them. A pic of the rating plate might also be a good idea.
 
As mentioned, check with its manufacturer. Further, You might consider that it wont be loaded at all near its rated capacity. Despite bearings maybe not optimal for vertical orientation, you may get considerable lifespan from them.
Btw, motors what are intended to be vertical will usually have eyes oriented for vertical picking.
 
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It’s a 284TC and here is the dats plate. Thanks guys for all the help.
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Fwiw, if you look up the ’specs on its bearings, they are plain ’ol deep groove ballbearings. I expect you plan some form of overrunning clutch & flexible shaftcoupling between motor & pony ?
Pretty low stress then being its only axial load is the rotor itself.
 
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Interesting. I don't know enough to say yes or no, but I thought the way the rotary phase converters worked was the third phase is generated by the third winding which is 270 degrees out from the first.... something like that.

I wonder if the four pole motor will effect that. Cool project.
 
ITS ALIVE!

I checked and it does not have any other mounting holes. It actually has the little drain hole on the bottom so it’s not a vertical. Just need to drag it across the floor and get it in a cradle. But man does it work slick, the 10hp press puts out tons more power on the RPC then it did on the VFD.
 
JTknives said:
It’s a bit complicated but I will try and explain it the best I can (not an expert). You feed 230 single phase into 2 of the lines in on the 3 phase motor. You get the motor spun up close to sync rpm and flip the power up. The moter will run on single phase. Now 3 phase use 3 wires and the motor is just being powered off 2 right now. The moter as it’s idling is acting like a generator and generating power in the 3 leg. You now can wire any other 3 phase motor up to this idler motor and it will run perfectly fine. Now if you want to get picky and save power cost you add in balancing capacitors between the phase lines L1,L2 and L3. This adjusts the voltage of the ghost leg up to the voltage of the others. You use capacitors to increase the power factor. Low power factor increases the amount of power you use and are charged for so a few dollars in capacitors goes along way. This is why I have a 7.5hp rotary phase converter as well. I don’t want to run the 25hp all the time becaus it’s idle amp draw on single phase is rather high at around 30 Amps. Now this is unbalanced and will get much lower once I install the capacitors. I use the 7.5hp on the surface grinder.

Basically in a bit shell your using a 3 phase motor as a rotating field transformer. Guess I could have just said that above lol, oh well it’s late.
Click to expand...

JT, let me be sure I understand what you're doing here. If I understand it, that is the first time I ever heard of that and I've worked around 3 ph motors in an industrial setting (mostly chemical plants) most of my life. Since we had 3 ph as the main power source there was never a reason for me to look for a way to "make" 3 ph.

1. You've got the 25hp motor wired to 230 vac with 2 phases, I 240 vac leg each to L1 and L2 with L3 being "open" at this time.

2. You wire a pigtail off L1, L2, L3 to a disconnect which goes to your desired "main" 3 ph motor (10 hp?). So, when disconnect is closed you have the 25 hp and the 10 hp motor in parallel?

3. You've got a 1.5 hp single ph motor connected to 25hp motor via a pulley/belt setup so you turn the 1.5 hp motor on and start spinning the 25 hp motor. Once 25 hp motor reaches close to full speed (1770 in this case), you can close the disconnect to 10 hp motor and it's getting 3 ph power? I guess still 240 vac range? You can then start 'n stop the 10 hp motor as you desire and the 25 hp motor just keeps putting out the 3 ph without a load?

If the above is how it works - that's slick and it's been a good day.... because I've learned something today.

Ken H>
 
Ken H> said:
JT, let me be sure I understand what you're doing here. If I understand it, that is the first time I ever heard of that and I've worked around 3 ph motors in an industrial setting (mostly chemical plants) most of my life. Since we had 3 ph as the main power source there was never a reason for me to look for a way to "make" 3 ph.

1. You've got the 25hp motor wired to 230 vac with 2 phases, I 240 vac leg each to L1 and L2 with L3 being "open" at this time.

2. You wire a pigtail off L1, L2, L3 to a disconnect which goes to your desired "main" 3 ph motor (10 hp?). So, when disconnect is closed you have the 25 hp and the 10 hp motor in parallel?

3. You've got a 1.5 hp single ph motor connected to 25hp motor via a pulley/belt setup so you turn the 1.5 hp motor on and start spinning the 25 hp motor. Once 25 hp motor reaches close to full speed (1770 in this case), you can close the disconnect to 10 hp motor and it's getting 3 ph power? I guess still 240 vac range? You can then start 'n stop the 10 hp motor as you desire and the 25 hp motor just keeps putting out the 3 ph without a load?

If the above is how it works - that's slick and it's been a good day.... because I've learned something today.

Ken H>
Click to expand...
Yes. Aside from switching off the small ’Ponymotor’ once the 25hp is running, Thats how it works. Its helpful to use an over running clutch or some shaft disconnecting method between the two, but not 100% needed.
Its not perfect 3Ø, either voltage or waveform. But it works well enough.
 
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JT, you say the press puts out more power with your RPC system than it did with a VFD drive - why do you think that is? Was the VFD not putting out it's rated 10 hp and getting bogged down? With the VFD putting out the rated voltage at 60 cycle.... (excuse me, Hertz) - I don't understand why the RPC would provide more power.

In all my years of working with VFD drives in industry I've never heard of a motor not putting out it's rated power on a VFD compared to a direct connection to line voltage. Please understand, I'm not doubting you at all, just trying to understand.

Ken H>
 
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