Need help diagnosing motor problem

[Matt Day]

6203 bearings have always been metric series bearings. Are you sure you didn't misread it? .

Positive. Apparently these are not very common. Silly American bearings!

http://www.vxb.com/page/bearings/PROD/Kit8194

[Mike Schuch]

The Delta turret arm RAS's I have worked on have all had centrifugal switches instead of potential relays. But the Delta Turret arm RAS's I have worked on have all been older models... quite a bit older. Centrifugal switches and potential relays are two ways to accomplish the same thing... disengage the starting capacitor when the motor is up to speed. If Delta switched to potential relays from centrifugal switches good for them as I have more than one RAS motor that was burnt out by a centrifugal switch that would not disengage. The wiring diagram looks like a potential relay is used on your saw. A potential relay opens when a specific voltage is reached. If the potential relay is stuck open the motor will just humm when energized. If the potential relay is stuck closed the motor will come up to speed then start smoking then burn out the windings ruining the motor.

Delta no longer carries centrifugal switches (actually I guess Delta is no longer Delta). You should be able to match a potential relay with one of similar spec from grainger if the potential relay is your issue.

If your problem was the starting capacitor I doubt the motor would spin at all. It would probably just sit there and hum when the motor is energized.

[Matt Day]

The "relay" on the diagram is a Klixon® 4CR series starter relay motor protector (4CR-1-780).

The other item shown (round one) is a Klixon phenolic motor protector (cgj52cd). This is the piece that has the red reset button on it, the same piece where I saw a spark.

I see no signs of discoloration or burning on the motor windings. I am hopeful that the motor can be saved. I'm hoping it was just coincidental that something failed after I changed the wiring to 220. I traced every wire and it matches up to the wiring diagrams.

I agree with you Mike, it does sound like the relay might be the culprit. I have a call into the manufacture and hopefully I will get some information on how to test it. Do you know? I also need to find a place to buy one if that is necessary. I only found one place online, and I was hoping to find a better price ($50).

[Pat Barry]

When I turned it on for the first time on 220, it turned on right away and spun up but it was loud, louder than a motor without a blade should be. As I was checking it out, I saw a spark at the motor protector. I turned it off immediately and checked for damage, saw none other than a touch of black, then rechecked all the wiring. Next time I tried it, it ran loudly for about 20 seconds before I saw/smelled smoke from the fan/winding area. I immediately shut it down again and have not tried it again since. I hope I didn't let all the magic smoke out! I did notice the capacitor was warm for quite a while after I turned it off an unplugged it - like 20 minutes later.

There is a distinctive, putrid smell to electronics that are smoking and that if you have seen the smoke the windings are likely damaged.

[Rod Sheridan]

Matt, measure the current in the starting capacitor once the motor has started. It should be zero once the relay opens.

If the relay doesn't open, that's your problem...........Rod.

[Matt Day]

I finally got my bearings after a mid-shipment by Amazon or their 3rd party seller. I reassembled the motor and changed the wiring back to 110, and all I get now is a loud buzzing with no shaft movement. I also tried removing the motor brake (thinking that was somehow locked in the brake position) which did not help.

I'd like to find out how to test the starter relay and the motor protector but I can't seem to find anything about these particular components online.

I called Klixon about 10 times last week and left messages and have not gotten a call back.

Edit- Rod, I only flick the power on for a second for fear of burning something up, so I can't run your test.

[Matt Day]

I tried a new cap to no avail as well.

I'm wondering if it would be better to cough up the $80 and just replace both the start relay and motor protector.

[David L Morse]

$80 seems like a lot to spend if it turns out your motor has shorted windings. What kind of test equipment do you have? Can you test current and voltage?

[Matt Day]

Yup, I have a multimeter. I just don't know what and where to measure!

[Matt Day]

Here's the 110 diagram.

[Matt Day]

And here are a couple pictures of the components in question. Note the motor protector has soldered connections. I can undo them and re solder if necessary.

[David L Morse]

In an earlier post Mike Schuch pointed out that shorted start windings can be an issue with this saw so let's check that first. Set your multimeter for AC
volts and the proper range if not auto ranging. Connect across the start winding: (you have clip leads, right?)
RAS Motor 1.jpg
Briefly turn on the saw and measure the voltage. It should be in the 60-90 volt range (or thereabouts).

[Matt Day]

Thanks David,
Indont have clip leads but I found some alligator clips to keep them in place. I tried your suggestion but could not get a reading. The buzzing sound is quite loud and I worry I'll do further damage. I tried it for maybe 2 seconds and the multimeter didn't settle on a reading.
I really appreciate your help.

[John K Jordan]

Do you have a motor shop nearby? They could test, diagnose, and repair if practical. Might save a lot of time and expense, especially if you are not experienced with working on electric motors.

[Matt Day]

I decided to take the motor to a repair shop to diagnose the windings, motor protector, and start relay. They have a backlog but I hope to hear back in about a week.