# Bridgeport Motor Issue (Video)



## Ceej0103 (Dec 21, 2020)

Hey guys,

Been running this Bridgeport for 6-8 months now after a complete teardown and rebuild.  I didn't do anything to the motor except paint it.  It's run on single phase using a VFD.  No changes to the wiring configuration have been made since it was originally powered up.  I started noticing the motor being a little sluggish to get spun up about a month ago.  I didn't really think anything of it as I had also recently started running the machine in back gear and figured the extra gearing was the culprit.  

Anyhow, you can see from the video that it's humming and wanting to go, but just wont spin up and run.  I'm not a motor guy so coming here to see if anyone knows the obvious issue or can recommend how I might test the motor to start narrowing it down.  The machine was in it's neutral position during the video, so very little load on the motor.


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## Lo-Fi (Dec 21, 2020)

Looks like it's lost a phase or two, so you'll need to check resistances over each of the sets of coils. 
Some motor and wiring data may be helpful to post to be able to be more specific.


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## Jakedaawg (Dec 21, 2020)

I'd start by verifying power supply from vfd


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## benmychree (Dec 21, 2020)

Jakedaawg said:


> I'd start by verifying power supply from vfd


I agree with that, you could wire it VFD up to another motor and see if it operated satisfactorily


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## Ulma Doctor (Dec 21, 2020)

what type of VFD are we playing with? 
can you post a picture as wired on both ends? ( the VFD and Motor wiring)

the settings could be off, the carrier frequency sounds high


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## Nutfarmer (Dec 21, 2020)

Check the voltage between each leg and make sure it's the same on all legs . Like Lo*-Fi  said it looks like one of the phases has dropped out. If so the problem is in the VFD.*


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## Mitch Alsup (Dec 21, 2020)

Maybe the start capacitor has died (or nearly so)
Maybe the start-to-run centrifical switch is not making "start" contact.

The above may be why one (or more) poles are not receiving the phase they need.

Otherwise start by verifying the voltages get to all 3 poles.

This is either a mechanical (switch) or chemical (dry capacitor) problem.


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## Lo-Fi (Dec 21, 2020)

This'll be three phase, so no caps or switch on this one. I was thinking start basic by measuring resistance of the windings, then work back from there. If you've got even resistance between pairs, you can be fairly confident it's time to look at the VFD assuming it's not just a connection issue. I've not yet tried putting a meter on a VFD to measure output voltage. I have a feeling the PWM output will throw a digital into a fit... 

Another motor to prove the VFD on is a great shout if available. It behaves like a motor that's either being run way under volt or with a phase or two disconnected, though the screaming can also be caused by having wiring incorrect on certain types of motor (two speed from personal experience), which is also accompanied by rapid rotor heating.


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## Ulma Doctor (Dec 21, 2020)

Are you trying to use a vfd on a single phase capacitor start motor?


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## Ceej0103 (Dec 21, 2020)

Thanks for all the replies guys.  A little more info for you.  It's the typical 1 1/2 HP motor.  Attaching a picture of the plate.  It's wired for low voltage.  Definitely a 3-phase motor so the comments about a single phase/start capacitor don't apply. 

I have two VFDs.  One that has been connected to the machine when it was functioning properly, which is a cheapo from amazon and a second KBAC that's attached to my belt grinder.  I wired up the KBAC and had the same result.  On the Amazon Cheapo I tested both input hots to ground and got 120v on each so it's getting the correct input voltage.  On the output side of the VFD I tested each pole to ground and was getting mixed results.  One pole might read 120v, and the other two wouldnt read or would bounce sporadically from 120-180v.  That said, I did test the motor with the KBAC, which is functioning correctly with my 3-phase Baldor on my belt grinder and the results were the same.  I guess tomorrow I should test the Amazon Cheapo on the belt grinder motor to see what happens.  That will tell me alot about the VFD.  Regardless, even if that VFD tests poorly, not sure why the KBAC wouldn't run the Bridgeport motor sufficiently. 

Sorry for the picture quality...I have a power drawbar so getting a head on photo is difficult since the plate sits right behind it.


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## Ceej0103 (Dec 21, 2020)

Jakedaawg said:


> I'd start by verifying power supply from vfd



I addressed this is my post above; to test it further I'll hook it up to another motor tomorrow.


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## Ceej0103 (Dec 21, 2020)

Ulma Doctor said:


> what type of VFD are we playing with?
> can you post a picture as wired on both ends? ( the VFD and Motor wiring)
> 
> the settings could be off, the carrier frequency sounds high



It's a cheapo from Amazon.  I'll post some more pictures tomorrow. The way that it's wired has worked fine on the machine for months.  In the video, I was running the motor off a different drive (KBAC) to see if I could isolate the issue to the VFD.


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## Ceej0103 (Dec 21, 2020)

Lo-Fi said:


> This'll be three phase, so no caps or switch on this one. I was thinking start basic by measuring resistance of the windings, then work back from there. If you've got even resistance between pairs, you can be fairly confident it's time to look at the VFD assuming it's not just a connection issue. I've not yet tried putting a meter on a VFD to measure output voltage. I have a feeling the PWM output will throw a digital into a fit...
> 
> Another motor to prove the VFD on is a great shout if available. It behaves like a motor that's either being run way under volt or with a phase or two disconnected, though the screaming can also be caused by having wiring incorrect on certain types of motor (two speed from personal experience), which is also accompanied by rapid rotor heating.



When I put a meter on the output side of the VFD, it was giving me some really wonky readings.  The first pole was almost always 120v, but the second and third pole were all over the place.  Is that due to PWM?


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## ttabbal (Dec 21, 2020)

I suspect the meter doesn't like the PWM. If you have a scope, that would work, but if swapping to another motor works then it's probably the motor that has an issue. Did you test resistance of the windings? With the VFD disconnected, each winding should be similar resistance.


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## Ceej0103 (Dec 21, 2020)

ttabbal said:


> I suspect the meter doesn't like the PWM. If you have a scope, that would work, but if swapping to another motor works then it's probably the motor that has an issue. Did you test resistance of the windings? With the VFD disconnected, each winding should be similar resistance.



I did not. When performing that test is it necessary to de-couple the wires?  The motor has 9 separate wires labeled 1-9 if I recall correctly. I think 6-5-4 are connected together and 9-1, 8-2, and 7-3. What number gets tested against what other number during the resistance test?


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## metric_taper (Dec 21, 2020)

A quality designed VFD would error out. I'm in agreement with others that it's the VFD.
I heard the noise from a switch in the video, is this wired to the control input discretes of the VFD, or are you switching the the motor connections between the VFD and motor?
If so, you know that most likely blew up the VFD output drive transistors.
Much more information needed, like a photo of the whole system, and a wiring diagram.


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## Ceej0103 (Dec 21, 2020)

metric_taper said:


> A quality designed VFD would error out. I'm in agreement with others that it's the VFD.
> I heard the noise from a switch in the video, is this wired to the control input discretes of the VFD, or are you switching the the motor connections between the VFD and motor?
> If so, you know that most likely blew up the VFD output drive transistors.
> Much more information needed, like a photo of the whole system, and a wiring diagram.



Sorry, not completely sure what you're asking. Wiring goes like this:  Panel to VFD Ground, Hot, Hot -> 3 VFD Poles out to the Bridgeport's Drum Switch - > Drum Switch to the motor.  I haven't pulled it all apart, but it's wired low voltage so I'm fairly certain that means motor wires 6 - 5 - 4 are bundled together with a wire nut.  9 - 1, 8 - 2, and 7 - 3 each get connected to a wire coming from the drum switch, which correspond to one of the poles on the VFD.  

To operate, I turn the VFD on at 60hz and then use the drum switch to operate the machine.  Will this ruin a VFD?  Check my next post, VFD is good.


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## metric_taper (Dec 21, 2020)

Ceej0103 said:


> Sorry, not completely sure what you're asking. Wiring goes like this:  Panel to VFD Ground, Hot, Hot -> 3 VFD Poles out to the Bridgeport's Drum Switch - > Drum Switch to the motor.  I haven't pulled it all apart, but it's wired low voltage so I'm fairly certain that means motor wires 6 - 5 - 4 are bundled together with a wire nut.  9 - 1, 8 - 2, and 7 - 3 each get connected to a wire coming from the drum switch, which correspond to one of the poles on the VFD.
> 
> To operate, I turn the VFD on at 60hz and then use the drum switch to operate the machine.  Will this ruin a VFD?  Check my next post, VFD is good.


I think you are using the drum switch between the VFD and the motor, and that is a HUGE NEVER DO for a VFD. You always hard wire the VFD to the motor. Switching while running causes huge voltage spikes, these exceed the transistor break down voltage. I'm guessing you blew up your VFD. And it should have error'd out on this. You may have been doing this for a long time, but I'm believing this finally failed.


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## Ceej0103 (Dec 21, 2020)

Well I knew I couldn't sleep unless I tested it on a different motor.  Here's the VFD running on my belt grinder.  This is the same way I wire it for the Bridgeport motor.  From left to right on the VFD, the first post is ground, second is L1, third is L2.  On the right side they're labeled like U V W or something like that, but those are my lines out to the 3 phase motor.  Those get connected to whatever set of lines I decide on the motor side, and a pair can be switched if I need to switch direction of the motor.  I think this is rather common.  

Also, I've eliminated the drum switch from the equation and wired directly to the motor. No difference.  I'm fairly certain we can rule out the VFD and start looking at the motor.


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## metric_taper (Dec 21, 2020)

Ceej0103 said:


> Well I knew I couldn't sleep unless I tested it on a different motor.  Here's the VFD running on my belt grinder.  This is the same way I wire it for the Bridgeport motor.  From left to right on the VFD, the first post is ground, second is L1, third is L2.  On the right side they're labeled like U V W or something like that, but those are my lines out to the 3 phase motor.  Those get connected to whatever set of lines I decide on the motor side, and a pair can be switched if I need to switch direction of the motor.  I think this is rather common.
> 
> Also, I've eliminated the drum switch from the equation and wired directly to the motor. No difference.  I'm fairly certain we can rule out the VFD and start looking at the motor.


OK, have you used an ohm meter to motor ground for each of the 3 leads? That's the other issue with large voltage spikes they can break through the winding insulation and produce a short connection. Also look for any frayed old motor leads or your splices and verify they have not gone to ground.


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## Ceej0103 (Dec 21, 2020)

metric_taper said:


> I think you are using the drum switch between the VFD and the motor, and that is a HUGE NEVER DO for a VFD. You always hard wire the VFD to the motor. Switching while running causes huge voltage spikes, these exceed the transistor break down voltage. I'm guessing you blew up your VFD. And it should have error'd out on this. You may have been doing this for a long time, but I'm believing this finally failed.



Gotcha, didn't know that.  But it looks like the VFD survived that mistake as it just ran my 3-phase belt grinder motor without a hiccup.  When I get this resolved, I'll eliminate that drum switch. I'm assuming there's some other type of switch that can be wired directly in to the VFD to switch directions and turn on/off?  The VFD is mounted on the side of my machine and would be a ***** to turn it on and off in its current location.


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## Lo-Fi (Dec 21, 2020)

As pointed out, switching between a load and the VFD is not recommended. However, as it's running the belt grinder okay, you'd better look at the mill motor. Measure between each paired connection and the triple connection. They should be same resistance, but I'll bet they're not. Also check between the pairs. You can split the windings out and test in isolation, but this should be enough for a quick test. 

Switching two of the windings is a common way to reverse a direct connected motor, but not the with a VFD. The VFD itself is capable of running the motor reverse, with no switches in the circuit. You can get a remote for most VFD, which allow control when the unit is remote mounted like you have, which is not uncommon.


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## Ceej0103 (Dec 21, 2020)

metric_taper said:


> OK, have you used an ohm meter to motor ground for each of the 3 leads? That's the other issue with large voltage spikes they can break through the winding insulation and produce a short connection. Also look for any frayed old motor leads or your splices and verify they have not gone to ground.




I have not, that will be my task for tomorrow morning.  Several have mentioned testing the resistance on the windings.  I'm still trying to get a clear picture of what exactly im testing.  As mentioned prior, I believe 6-5-4 are connected together and 9-1, 8-2, and 7-3 are connected together.  Am I testing those bundles of wires against each other or testing each of those bundles to the casting of the motor (ground)?  What should I be seeing?  I guess I could go to google and search for how to test a 3-phase motor also.


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## Ceej0103 (Dec 21, 2020)

Lo-Fi said:


> As pointed out, switching between a load and the VFD is not recommended. However, as it's running the belt grinder okay, you'd better look at the mill motor. Measure between each paired connection and the triple connection. They should be same resistance, but I'll bet they're not.
> 
> Switching two of the windings is a common way to reverse a direct connected motor, but not the with a VFD. The VFD itself is capable of running the motor reverse, with no switches in the circuit. You can get a remote for most VFD, which allow control when the unit is remote mounted like you have, which is not uncommon.



Gotcha, test the paired to the triple.  Will report in tomorrow with the results.


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## metric_taper (Dec 21, 2020)

Ceej0103 said:


> I have not, that will be my task for tomorrow morning.  Several have mentioned testing the resistance on the windings.  I'm still trying to get a clear picture of what exactly im testing.  As mentioned prior, I believe 6-5-4 are connected together and 9-1, 8-2, and 7-3 are connected together.  Am I testing those bundles of wires against each other or testing each of those bundles to the casting of the motor (ground)?  What should I be seeing?  I guess I could go to google and search for how to test a 3-phase motor also.


As Lo-Fi said, for lead testing.
You can make the VFD use low voltage discretes and wire this to the drum switch, so it still controls the motor, but there is no high voltage going to the drum switch. You need to look at the manual for the VFD, it should have a 3 wire connection, a common power or ground wire (DC +12 or +24, or ground), and one of the discretes for Forward, and another for Reverse, your drum switch makes the connection. This needs 3 wires. And not to be confused with the 3 wires start stop type common connection.
I'm assuming you have a Hyangyang VFD, but that's a guess, I've attached the manual in pdf for that, and a diagram. Note the lower left side of it for the FOR/REV external discrete control.
Dang, manual was too big to attach.


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## Ceej0103 (Dec 22, 2020)

metric_taper said:


> As Lo-Fi said, for lead testing.
> You can make the VFD use low voltage discretes and wire this to the drum switch, so it still controls the motor, but there is no high voltage going to the drum switch. You need to look at the manual for the VFD, it should have a 3 wire connection, a common power or ground wire (DC +12 or +24, or ground), and one of the discretes for Forward, and another for Reverse, your drum switch makes the connection. This needs 3 wires. And not to be confused with the 3 wires start stop type common connection.
> I'm assuming you have a Hyangyang VFD, but that's a guess, I've attached the manual in pdf for that, and a diagram. Note the lower left side of it for the FOR/REV external discrete control.
> Dang, manual was too big to attach.



Dude!  Thanks so much.  I completely understand what you're saying about just sending a low voltage signal to the VFD to control VFD operations; just haven't done my homework and read the manual.  I need to.  I have a lathe that's about ready to get a new 5hp motor and I'll need to be able to wire in the VFD to allow for use of the switches that control powering the machine from the apron.  I'll start reading up.  

Here's the VFD...I just went back in my Amazon order history and found it.  I have the manual in the garage. 






						LAPOND High Performance VFD Inverter VFD Drive 2.2KW 220V 3HP 9.6A,Variable Frequency Drive for Motor Speed Control,SVD-PS Series: Amazon.com: Tools & Home Improvement
					

LAPOND High Performance VFD Inverter VFD Drive 2.2KW 220V 3HP 9.6A,Variable Frequency Drive for Motor Speed Control,SVD-PS Series: Amazon.com: Tools & Home Improvement



					www.amazon.com


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## Ceej0103 (Dec 22, 2020)

Ok here's the updates.  I'm not sure what motor I was remembering but this thing definitely doesn't have 9 wires like the motor plate indicates.  All I'm seeing is 3 wires.  See attached pictures.  I tested resistance across each of the three wires and got a constant value of 12.5 ohms.  I tested each wire to the motor housing (ground) and got OL (Open Line) for that test, which is what you would expect with a good motor. I'm baffled. 

For one, the plate on this motor suggests it has 9 wires and a low/high voltage wiring option.  I'm seeing 3 wires.  And even with 3 wires, there's no wild variation of resistance across the windings and there is apparently no grounded winding.

So....what do I have on my hands here?


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## Lo-Fi (Dec 22, 2020)

Puzzling, but probably good news for your motor... Could you post the data plate from the motor? 

I'm guessing the grinder isn't anywhere near the hp rating of the mill, so that might be a false positive on the VFD having survived it's outputs being switched. I'm trying to think up ways to test it...


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## Ceej0103 (Dec 22, 2020)

Lo-Fi said:


> Puzzling, but probably good news for your motor... Could you post the data plate from the motor?
> 
> I'm guessing the grinder isn't anywhere near the hp rating of the mill, so that might be a false positive on the VFD having survived it's outputs being switched. I'm trying to think up ways to test it...



The grinder motor is actually beefier...it's 3 HP as compared to the 1 1/2 HP on the mill.  Here's the data plate.


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## metric_taper (Dec 22, 2020)

Ceej0103 said:


> Ok here's the updates.  I'm not sure what motor I was remembering but this thing definitely doesn't have 9 wires like the motor plate indicates.  All I'm seeing is 3 wires.  See attached pictures.  I tested resistance across each of the three wires and got a constant value of 12.5 ohms.  I tested each wire to the motor housing (ground) and got OL (Open Line) for that test, which is what you would expect with a good motor. I'm baffled.
> 
> For one, the plate on this motor suggests it has 9 wires and a low/high voltage wiring option.  I'm seeing 3 wires.  And even with 3 wires, there's no wild variation of resistance across the windings and there is apparently no grounded winding.
> 
> So....what do I have on my hands here?


Seems if the actual motor does not match the nameplate, I would guess it had been rewired by a motor shop in the past.
It does not make sense that the VFD drives the grinder but not this motor. All you did was paint it? Just the exterior, and did not split the bell housing off like you have for the photos? Have you tried running the motor with without connecting the shaft to the machine?


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## Ceej0103 (Dec 22, 2020)

metric_taper said:


> Seems if the actual motor does not match the nameplate, I would guess it had been rewired by a motor shop in the past.
> It does not make sense that the VFD drives the grinder but not this motor. All you did was paint it? Just the exterior, and did not split the bell housing off like you have for the photos? Have you tried running the motor with without connecting the shaft to the machine?



Yes, this is the first time I've pulled it apart.  I have not tried running the motor with the shaft free of the machine.  Are you thinking maybe the machine is frozen and not allowing the motor to spin up?  I don't think that's the case.  I can freely spin the spindle in gear and out of gear.  The motor did spin, albeit very slowly in the video posted early in this thread.  I guess pulling it and testing it on the bench is the only way to truly know that there isn't a problem in the bull gear/etc.  And I suppose I'll probably need to take it to a motor shop to get them to rewind it or at least test it to make sure I'm not just a moron, so it has to come out anyways.  I'll give it a shot tomorrow.


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## metric_taper (Dec 23, 2020)

Ceej0103 said:


> Yes, this is the first time I've pulled it apart.  I have not tried running the motor with the shaft free of the machine.  Are you thinking maybe the machine is frozen and not allowing the motor to spin up?  I don't think that's the case.  I can freely spin the spindle in gear and out of gear.  The motor did spin, albeit very slowly in the video posted early in this thread.  I guess pulling it and testing it on the bench is the only way to truly know that there isn't a problem in the bull gear/etc.  And I suppose I'll probably need to take it to a motor shop to get them to rewind it or at least test it to make sure I'm not just a moron, so it has to come out anyways.  I'll give it a shot tomorrow.


Did you take the other bell housing off the motor? Might be good to look at the winding and any connection wires between them there just to make sure nothing looks wrong. I think it would be wise to power just the motor without the mill load to see if it will spin up.
the link to the VFD indicates it is a vector controlled. They typically have an 'auto tune' feature, that is performed on the motor unloaded. I would try that and see if it may fix what has been a hidden problem. As always, RTFMFO.


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## Ceej0103 (Dec 23, 2020)

metric_taper said:


> Did you take the other bell housing off the motor? Might be good to look at the winding and any connection wires between them there just to make sure nothing looks wrong. I think it would be wise to power just the motor without the mill load to see if it will spin up.
> the link to the VFD indicates it is a vector controlled. They typically have an 'auto tune' feature, that is performed on the motor unloaded. I would try that and see if it may fix what has been a hidden problem. As always, RTFMFO.



I did not take the other end bell off the motor to take a look.  I didn't because I pulled it out today and put it on the bench.  I hooked the VFD back up and powered it.  The rotor spun up pretty well, but no where near 1760 RPM, which I believe is what these 3-phase 1 1/2HP motors should achieve at full potential.  I energized it while holding the Vari-Disc and the motor couldn't overcome my resistance to letting it spin. If it couldn't overcome my grip, there's no way it was going to overcome the resistance placed on it when it's installed in the machine, driving the gear train. I'm fairly certain I have something going on in the motor.  I took it to a local guy here that really know 3-phase motors and he said he's 100% certain someone has been inside and modified the original windings.  Anyhow, he's going to surge test it tomorrow and will give me some feedback.

I'll update this when I find out whats going on with it.


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## metric_taper (Dec 23, 2020)

You may want to search for a new motor from eBay, search for a frame type 145T. There are many new and used. I don't know what the "Y-T" frame modifier code does to the motor. But you either get one with the same shaft size, or you could get one with a bigger one, and remove the rotor, and machine it down on the lathe. One word of caution, make sure the transition from the larger shaft to the smaller machine shaft has a radii in the inside corner. 
I learned this the hard way.
I did this on my lathe  (7/8" shaft to 5/8" original 2 step pulley) when putting a 3 phase on it, there was just enough eccentricity of the old pulley, that it caused the shaft to snap off at the sharp inside corner. It ruined an inverter duty motor. I tried to press the shaft out of the rotor, and it broke one of the cast iron bucking plates on the harbor freight 20 ton press, this shot out sideways, and broke through the sheet rock wall, only stopped by the external plywood sheathing of the building. Never could get the shaft pressed out of the rotor. It sits as a project. And I was lucky it did not shoot at me, as it would have done some body damage.


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## metric_taper (Dec 23, 2020)

The "T" in the frame size say's the shaft diameter is the same, at least per this:








						What Electric Motor Frame Sizes Tell You
					

It is important to understand what the motor frame is telling you when it comes to mounting a motor. Make sure you know what to look for before you mount your motor.




					www.hecoinc.com
				



The "Y"  the motor has special mounting dimensions. That may be an issue, or you make an adapter plate.


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## metric_taper (Dec 23, 2020)

Forgive my ignorance on Bridgeport motors. Looks like it is a "C" face motor. And it's non standard or custom. Same problem I have with my Wells-Index mill.





						Bridgeport 2HP Motor-New  - Industrial Control & Automation
					

Bridgeport 2HP Motor-New



					www.icai-online.com
				



Pricey fix.


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## Ceej0103 (Dec 23, 2020)

metric_taper said:


> You may want to search for a new motor from eBay, search for a frame type 145T. There are many new and used. I don't know what the "Y-T" frame modifier code does to the motor. But you either get one with the same shaft size, or you could get one with a bigger one, and remove the rotor, and machine it down on the lathe. One word of caution, make sure the transition from the larger shaft to the smaller machine shaft has a radii in the inside corner.
> I learned this the hard way.
> I did this on my lathe  (7/8" shaft to 5/8" original 2 step pulley) when putting a 3 phase on it, there was just enough eccentricity of the old pulley, that it caused the shaft to snap off at the sharp inside corner. It ruined an inverter duty motor. I tried to press the shaft out of the rotor, and it broke one of the cast iron bucking plates on the harbor freight 20 ton press, this shot out sideways, and broke through the sheet rock wall, only stopped by the external plywood sheathing of the building. Never could get the shaft pressed out of the rotor. It sits as a project. And I was lucky it did not shoot at me, as it would have done some body damage.





metric_taper said:


> The "T" in the frame size say's the shaft diameter is the same, at least per this:
> 
> 
> 
> ...





metric_taper said:


> Forgive my ignorance on Bridgeport motors. Looks like it is a "C" face motor. And it's non standard or custom. Same problem I have with my Wells-Index mill.
> 
> 
> 
> ...



Glad you dodged that bullet.  Yeah that's what I've gathered from my google searching when this issues arose.  I was thinking just to replace it with a decent inverter duty motor, but looks like finding something that has the correct shaft length/diameter is challenging.  Then you need to make an adapter plate to mount.  This sounds like a cool project, but when your mill is down and your lathe's 5hp motor is sitting on the floor next to it, that would be a tough job. 

That's definitely a pricey replacement for only 2 HP.  I paid half that for a very nice 3-phase 3HP Baldor for the grinder.   

I did read that H&W sold an adapter plate, but that post/thread was really dated and I'm not finding anything like that on their current offerings. We'll see what my motor guy says.


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## Ceej0103 (Dec 23, 2020)

metric_taper said:


> Forgive my ignorance on Bridgeport motors. Looks like it is a "C" face motor. And it's non standard or custom. Same problem I have with my Wells-Index mill.
> 
> 
> 
> ...



Found something...little better.  Would like to get to 2HP if I'm investing the money.  Maybe they can just sell me the adapter plate.









						Three Phase Conversion Kit for 1 HP Bridgeport Motor | SP23PH
					

Lead time is generally 3-5 days to ship.




					www.machinerypartsdepot.com
				





EDIT: Nevermind, I think this is for the step pulley configuration.


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## Ulma Doctor (Dec 23, 2020)

$650 for a single phase motor is a bit steep when you could get it for half price here...









						1.5 HP Baldor Reliance 35M691-3032G1  | eBay
					

Find many great new & used options and get the best deals for 1.5 HP Baldor Reliance 35M691-3032G1 at the best online prices at eBay! Free shipping for many products!



					www.ebay.com
				




you'll still need to punch out the pulley to 7/8"


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## Ceej0103 (Dec 24, 2020)

Ulma Doctor said:


> $650 for a single phase motor is a bit steep when you could get it for half price here...
> 
> 
> 
> ...



That particular package was 1 HP (1J stock BP) to a 3-phase 1.5HP Baldor.  But yes, still a little expensive.  When you say "punch out the pulley", what do you mean?  I have a vari-speed machine and the drive aspect of the motor is the var-discs and they have bushings.  So if I were to buy a different motor with a larger shaft, I understand boring out the internal diameter of the vari-disc and cutting a new keyway, but I'm not quite sure how the bushings would be solved. Just find some suitable bushings and install them in the vari-discs?


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## Ulma Doctor (Dec 24, 2020)

Ceej0103 said:


> That particular package was 1 HP (1J stock BP) to a 3-phase 1.5HP Baldor.  But yes, still a little expensive.  When you say "punch out the pulley", what do you mean?  I have a vari-speed machine and the drive aspect of the motor is the var-discs and they have bushings.  So if I were to buy a different motor with a larger shaft, I understand boring out the internal diameter of the vari-disc and cutting a new keyway, but I'm not quite sure how the bushings would be solved. Just find some suitable bushings and install them in the vari-discs?


my mistake, the 1hp motor pictured https://www.machinerypartsdepot.com/product/SP23PH
requires boring the pulley to 7/8" from 3/4"
that's for a 1J head, the motor won't work on a 2J , i didn't realize you had a 2J


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## Ceej0103 (Dec 30, 2020)

Hey guys, got an update for you.

So the motor surge tested fine.  As mentioned previous, looks like it's been re-wound as it no longer has 9-wires and only 3.  The place that tested the motor confirmed that it was hardwired for 480v.  I've been running at 240v.  Looks like there's mixed schools on whether underpowering a motor will hurt it, but the surge testing confirmed the motor is still in perfectly good condition and the servicer said he had it running just fine.  He did say I was looking at $700-750 to rewind it for 240v.  That's not worth it....I can get a new one for close to that.

Before I go that route, I'm going to see if I can find a step-up transformer option to get me to 480v.  Does anyone know if there's a VFD out there that provides single to three phase output + a step up from 240v to 480v?  Any advice on the most efficient way to do this would be great.  If it's cost prohibitive, I may just order a new motor.

Remains a mystery as to why it would work for several months and all of a sudden it wont.


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## ttabbal (Dec 30, 2020)

VFDs need the feedback from the motor to work. Trying to run them into a transformer will likely cause them to shut down in confusion. You might be able to do it the other way and use a transformer to go from single phase 240->480, then a 480V VFD. 

You can use transformers on rotary phase converters though those aren't cheap either. You could build one for a more reasonable price. 

I'm also confused why it would work for a while then stop. I'm glad that the shop was at least able to explain what's up though. 

If it were me, I'd replace the motor with a dual voltage or 240V and use the 240V VFD. 

I don't know if it works that way, but maybe build a RPC that outputs 480V and lose the VFD entirely. I'm not that familiar with RPCs.


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## Lo-Fi (Dec 30, 2020)

Low to high volt VFD are available, but they're spendy. You might as well have it rewound. My experience with high volt motors run on lower voltage is that they run, but obviously nowhere near their rated output and that starting can be hit and miss. You might be able to _rewire_ that motor (not rewind) if you can find and access where wires from each winding are joined. Ironically, I could have pointed you in the right direction for wiring the 9 wire up for low volt.


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## Ceej0103 (Dec 31, 2020)

Lo-Fi said:


> Low to high volt VFD are available, but they're spendy. You might as well have it rewound. My experience with high volt motors run on lower voltage is that they run, but obviously nowhere near their rated output and that starting can be hit and miss. You might be able to _rewire_ that motor (not rewind) if you can find and access where wires from each winding are joined. Ironically, I could have pointed you in the right direction for wiring the 9 wire up for low volt.



That's a great idea.  I'm picking the motor back up on Monday and I'll tear it down and see what I can see.  If you go back to like Page 3 of this thread you'll see pictures of the top of the motor and where the 3 wires are originating.  They wrap around the top of the windings in a yellowish sleeve.  Although it's been hardwired for 480v, will I still definitely have 9 individual leads in there somewhere that have been joined?  If I can find them, I'll have to test to figure out which are 1-9.  I think I saw some youtube videos on how to go about determining that.


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## Lo-Fi (Dec 31, 2020)




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## Janderso (Dec 31, 2020)

Ceej0103 said:


> at $700-750 to rewind it for 240v. That's not worth it....I can get a new one for close to that.


 = no kidding!!
"Hardwired for 480" I didn't know that was a thing? Don't they usually have two wiring options, 220 and 440?


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## Lo-Fi (Dec 31, 2020)

Yep, almost all two speed motors are wired ~400 something volts. Someone has been inside that one and fiddled, though. In the video I explain how to rearrange the connections for low volt single speed connection.


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## Ceej0103 (Jan 8, 2021)

Final update for this one.  There's still a chance I can un-do the hardwiring at 480v in the 1 1/2hp motor, but I just decided to upgrade to a 2HP motor instead.  I'll dig in to the 1 1/2 hp motor to have as a backup or sell it on ebay.  I'm sure someone out there is running 480 in their shop and could use it.  

Ended up going through matacoinc.com for the purchase.  Dennis over there (i think that was his name) gave me a decent price on the 2HP and the new vari-discs.  I bench tested the motor using the VFD that was hooked up to the 1 1/2hp motor and it was golden.  Even at only 5hz, I couldnt overcome the shaft from spinning.  At a full 60hz its nice and quiet and gives me a lot more output than the 1 1/2hp motor did.  I guess that's to be expected when you run a motor at 240v when it's wired for 480v.  If memory serves me correct, thats a recipe to get about 1/4 of the capability out of the motor.  So the VFD checks out fine.  Still no rhyme or reason as to why the VFD ran the 1 1/2hp for 9 months and then failed to run it. 

The machine really comes alive in high gear and running up to 3k RPM+.  I can really tell that I wasn't getting a full 1750rpm out of the 1 1/2hp motor because with the new 2HP wired for 240v, it feels like the machine is about to blast off and enter orbit.

Thanks everyone who donated your time to troubleshooting this issue.  Much appreciated.


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