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Forum topic by JMB posted 11-30-2015 01:06 AM 971 views 0 times favorited 19 replies Add to Favorites Watch
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JMB

23 posts in 2887 days


11-30-2015 01:06 AM

Topic tags/keywords: humor table saw table saw delta wiring question help unisaw problem will not start will not turn

Hey, all.

I finally tracked down a new old cabinet saw to replace my old old contractor saw.

It’s a 1985 Delta Unisaw. Part number on the manual is delta 422-04-651-0012

Bought it used. Tested it at the guy’s shop prior to purchase – started right up. So I pay the guy, load into my trailer, bring to my shop, load in, stick it in the corner to deal with later.

Two or three months go by while I get around to adding a 220 line to plug the thing in.

My electrician finally runs the 220 line and outlet last Friday.

Today, I decommission the old contractor saw, sweep up, and drop the new cabinet saw into place. I plug it in. Turn it on. Aaaaaand….

IT WON’T SPIN.

Great.

All I get is a buzzing sound from the switch housing. The start button won’t even stay down. It’s like the solenoid is not closing correctly. I tried pushing down the little tab inside the switch housing, which forces the contacts closed. Still buzzing, and the motor spindle spins INCREDIBLY SLOWLY. It’s like it wants to start up but cant. Like the polarities are conflicting with one another.

Here’s what I have done so far:

Removed incredibly heavy 80 year old three phase motor from saw.

Lost grip on incredibly heavy 80 year old three phase motor, dropped said motor inside saw cabinet housing, by way of fingers, and ultimately pulley.

Bruised, nearly broken finger

Definitely broken Pulley.

Yell. Curse. Smoke a ciggarette. Do something else. Return to problem after heart rate returns to normal.

Carefully lift incredibly heavy motor out of cabinet, into the light of day, to assess.

Remove cover plates and assess interior of motor housing.

Blow out dust.

Go get eye protection.

Blow out the rest of the dust.

Attempt to start again.

Buzzing sound. No spin.

Check power supply:

Voltmeter leads from power plug to switch red/white 120, red/black 240, black/white 120. Good so far.

Voltmeter leads from switch to motor:

With Switch off and tool plugged in: Zero Voltage across both phases and leads. To be expected

While holding the start switch down: Buzzing sound, random voltages (all over the place), nothing anywhere near 120 or 240 for any combination of black, white and red. 60V is maybe the highest I note. Not sure what that’s about.

Checked wiring diagram on motor housing. Open wiring housing and double checked all wires. 3 and 8 are reversed. (AHA!!)

Rewire correctly.

Attempt to turn on from switch.

Buzzing sound, no / slow spin (What the heck???)

Smoke another cigarette.

Double check wiring diagram for switch. All looks correct.

Write this post.

Thoughts??? Because I am ALL OUT OF IDEAS.

Thanks in advance.

Edit: This motor either does not use capacitors, or they are incorporated into the motor housing in some way that makes them not readily apparent. As there are not the usual one or two humps on the outside of the housing which would be the tell tale placement of a capacitor.

-- If I can't fix it, it wern't broke in the first place!


19 replies so far

View SawSucker's profile

SawSucker

110 posts in 390 days


#1 posted 11-30-2015 01:12 AM

It’s a three phase motor that your trying to make work on single phase ? I’d call your electrician.

View MrUnix's profile

MrUnix

4216 posts in 1661 days


#2 posted 11-30-2015 01:12 AM

It’s a 3-phase motor… do you have 3-phase power?

Cheers,
Brad

PS: There are no capacitors in a three phase motor.
PSS: The ‘start’ button is a momentary contact type – it should not ‘stay pushed in’ . It is (or should be) wired to the starter where there should be a contactor (relay) and heaters (overload protection).
PSSS: If it is a 1985 Unisaw, it’s only 30 years old, not 80 :)

-- Brad in FL - To be old and wise, you must first be young and stupid

View JMB's profile

JMB

23 posts in 2887 days


#3 posted 11-30-2015 01:39 AM

The motor can be wired for single phase 220V or three phase 440V. I currently have it wired for single phase.

The motor is either much older than the saw, or the manual, which says 1985, is not original to the saw, and it’s a much older saw.

I am clear on how the start button (momentary switch), starter, and contactor are meant to work. They aren’t doing what they are supposed to. Hence my post.

-- If I can't fix it, it wern't broke in the first place!

View MrUnix's profile

MrUnix

4216 posts in 1661 days


#4 posted 11-30-2015 01:42 AM

The motor can be wired for single phase 220V or three phase 440V. I currently have it wired for single phase.

Well, then you got me… I have never seen such a beast, and have no idea how that could even be possible as they operate completely different. I have seen starters that could be used by both single and three phase, but never a motor. Maybe post a picture of the motor plate showing the wiring diagram along with one of the starter and other associated bits.

Cheers,
Brad

PS: You can date the saw if you have the serial number – check here. (and 80 years would make it 1935, which would pre-date the Unisaw by a few years).

-- Brad in FL - To be old and wise, you must first be young and stupid

View TheFridge's profile

TheFridge

5765 posts in 948 days


#5 posted 11-30-2015 01:49 AM

Post a pic of the motor please.

I’ve never seen a motor capable of 3 or 1 phase

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View JMB's profile

JMB

23 posts in 2887 days


#6 posted 11-30-2015 02:18 AM

It would seem that may be the answer, then. This is a three phase motor, and we need three phase power.

Suffice it to say, electricity is not my forte. But I can build just about anything. Thanks for the brainstorming session. I’ll let you all know how it goes tomorrow

-- If I can't fix it, it wern't broke in the first place!

View TheFridge's profile

TheFridge

5765 posts in 948 days


#7 posted 11-30-2015 02:22 AM

VFDs are cheap. Plus ramp up and braking are very nice features.

-- Shooting down the walls of heartache. Bang bang. I am. The warrior.

View MrUnix's profile

MrUnix

4216 posts in 1661 days


#8 posted 11-30-2015 02:22 AM


It would seem that may be the answer, then. This is a three phase motor, and we need three phase power.

Suffice it to say, electricity is not my forte. But I can build just about anything. Thanks for the brainstorming session. I ll let you all know how it goes tomorrow

- JMB

You don’t need a three phase supply, just need to supply three phase to the motor :)
That can be done with your existing single phase 240v supply you had installed… you just need to get a phase converter (VFD, RPC or static phase converter). The motor size will determine which is best. For 3HP or less, you are looking at around $150 or less for a VFD, which will give you all sorts of added benefits.

Cheers,
Brad

-- Brad in FL - To be old and wise, you must first be young and stupid

View DylanC's profile

DylanC

196 posts in 2136 days


#9 posted 12-03-2015 03:47 AM

I have the same saw…check out my post on getting it powered up with a static phase converter:

http://lumberjocks.com/DylanC/blog/21010

I ended up with a G5843 from Grizzly, but the G5842 would probably work also, for less money. IF you go the VFD route, you will probably have to buy a 7-10 hp VFD (on a minimum 30 Amp circuit) to eek out all 5 hp out of the motor. Or, you might be able to get a 3-hp drive and just “handicap” your saw to 3-hp by limiting the current supplied by the VFD. Not much of a handicap, really.

You don’t happen to have the manual for this saw, do you? I am still searching for one.

-- Dylan C ...Seems like all ever I make is sawdust...

View MrUnix's profile

MrUnix

4216 posts in 1661 days


#10 posted 12-03-2015 04:11 AM


I have the same saw…check out my post on getting it powered up with a static phase converter:

http://lumberjocks.com/DylanC/blog/21010

I ended up with a G5843 from Grizzly, but the G5842 would probably work also, for less money. IF you go the VFD route, you will probably have to buy a 7-10 hp VFD (on a minimum 30 Amp circuit) to eek out all 5 hp out of the motor. Or, you might be able to get a 3-hp drive and just “handicap” your saw to 3-hp by limiting the current supplied by the VFD. Not much of a handicap, really.

You don t happen to have the manual for this saw, do you? I am still searching for one.

- DylanC

I must have missed it… where did you get that it’s a 5HP motor? I actually have pretty much the same saw as well… with a 3hp 3 phase motor, and a FM50-202-c runs it perfectly, for about $150. It allows the motor to run at 100% power, along with all sorts of other goodies, like soft start, emergency stop feature, electronic breaking, variable speeds including up to 2X+ rated speed, etc, etc, etc… Using a static phase converter however WILL handicap your motor, reducing it’s output by about 1/3… they don’t really provide three phase power as they drop one leg immediately upon startup (so you are really running that three phase motor on single phase power, hence the power reduction). You also don’t get any of the extra benefits that a VFD provides.

Almost forgot- the manual can be found over at the vintagemachinery site:
Delta 10 inch Tilting Arbor Saw (Unisaw) 422-04-651-0012 Instruction Manual

Cheers,
Brad

PS: The “HP” rating on VFD’s is for marketing only… ignore it. Size based on FLA. Perfect example, that FM50 I mention is labeled as a ”2HP” unit, but has a 7.5A output capacity. My 3HP motor is rated at 7.4A FLA, so it works just fine. The “3HP” FM50-203-c is rated for up to 10.5A, and would have been more than needed (and would have had to been set for only ~70% of full current so it could provide proper overload protection). Even with a 5HP motor, there are plenty of people running them on that 3hp FM50 – go check over at the OWWM and PracticalMachinest site for dozens of examples.

-- Brad in FL - To be old and wise, you must first be young and stupid

View DylanC's profile

DylanC

196 posts in 2136 days


#11 posted 12-03-2015 04:30 AM

I guess I assumed that it was 5 hp, because that’s what I have. You are correct on the fact that MOST static converters only supply 3-phase power at startup, like the one I ALMOST bought from Enco. But the Grizzly converters are a bit different. They have a “Run Capacitor” that takes over after the motor has started and supplies continuous power to the third phase. However, the voltage is a bit “wild” and is not sinusoidal and still limits the peak power to 70% continuous, or 95% for 15 minutes with equal unloaded time for cooling. IF I ever loaded my saw to 4.8 hp, I doubt it would be for anywhere near 15 minutes. I also happen have a spare 5 or 7.5 hp motor and starter sitting around, so as soon as I can find time I will use the static converter to build a simple rotary converter. Not something everyone has access to, but it worked out for me. I agree that for a 3-hp motor the VFD option is better, but only because of the ramp-up and braking features. Running over 60 Hz would freak me out for two reasons: 1) Drop in available torque, and 2) not knowing how fast you can spin a 10” blade before it flies apart.

and MrUnix, would you happen to have a manual for this saw?

-- Dylan C ...Seems like all ever I make is sawdust...

View DylanC's profile

DylanC

196 posts in 2136 days


#12 posted 12-03-2015 04:51 AM

I had seen that manual and parts list at vintage machinery, but it didn’t mention an available 5 hp motor, so I assumed (maybe I should stop doing that) that it didn’t cover my saw. I just downloaded a copy…thanks for posting the link.

-- Dylan C ...Seems like all ever I make is sawdust...

View MrUnix's profile

MrUnix

4216 posts in 1661 days


#13 posted 12-03-2015 04:58 AM

I added a link to the manual above (I originally forgot to link it), and I’ll put the link again down below. And while running over rated speed is not something I would typically want to do, I do find the need to run at reduced speed frequently. With the VFD, the speed is variable from zero to over twice rated, and there is a separate control input (SP1) that when enabled, will set the frequency to any pre-set speed you want for convenience (rather than using the up/down buttons on the control pad, which you can still do as well). I’ve found that to be quite handy for cutting HDPE, plexiglass, thin aluminium and brass sheets, and other stuff where normal speed is too fast or causes stuff to melt in addition to being cut. And even at reduced speed, you still get full torque (until you get to about 5% or less of rated speed, when it gets kind of wonky). There are a lot of benefits of a VFD well beyond just programmable startup and stop times, and I wouldn’t hesitate one bit running a 5HP motor on one labeled as ‘3hp’ :)

Delta 10 inch Tilting Arbor Saw (Unisaw) 422-04-651-0012 Instruction Manual

Cheers,
Brad

PS: And they are cheaper than those Grizzly SPC’s as well!

-- Brad in FL - To be old and wise, you must first be young and stupid

View Karamba's profile

Karamba

116 posts in 398 days


#14 posted 12-03-2015 05:02 AM



The motor can be wired for single phase 220V or three phase 440V.

- JMB


Did the seller tell you that ?

View MrUnix's profile

MrUnix

4216 posts in 1661 days


#15 posted 12-03-2015 05:10 AM

The motor can be wired for single phase 220V or three phase 440V.
- JMB

Did the seller tell you that ?
- Karamba

I believe we already figured that one out :)

While I’m not positive, I’m pretty sure he was looking at the starter (correct me if I’m wrong JMB). Those can in fact be wired for either single or three phase, 240 or 480 volt (as well as 120 and possibly others). But just because the starter can be wired that way, it doesn’t mean the motor can… The starter has to be wired correctly for the voltage and phase of the motor, or you get… well, what was described in the original post (or worse, like a puff of smoke followed by darkness)!

Cheers,
Brad

PS: If the seller DID tell him that, then I’d say it’s a perfect example of OWWM rule #1!

-- Brad in FL - To be old and wise, you must first be young and stupid

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