Delta Table Saw – Motor issue – Capacitor?
Hello, I am wondering if anyone has experience with the following. I have a Delta table saw model 36-650C, motor is Cat No. 62-044 1.5HP, Ball bearing, Capacitor Start / Capacitor Run (V115/230; A 15/7.5, HZ 60, Phase 1, RPM 3450). The motor starts and runs fine when belt is not engaged with the blade/pulley. The blade/pulley also spin freely when not engaged with motor. Tried new belt. However, when I engage the motor with belt (pulley/blade) it trips the motor after a few seconds of trying to start. I suspect it is the start capacitor as opposed to the run capacitor because it starts and runs fine with no blade engaged via belt. The Start Capacitor is a Y.C Electrics Co “ABC Motor Starting Capacitor CAP 400MFD, W.V 125 V.AC, Y759.” The Run Capacitor has the following markings 40uF +10 -5%, 250 WVAC.
Question: would the above logic appear correct and if so, where can I obtain this Start Capacitor (I live in the Toronto, Ont, Canada area)? If not, any suggestions? Thanks, Steve
Replies
I believe McMaster's will deliver to Canada
Start Capacitors, 378-453.6 µ-F Capacitance
https://www.mcmaster.com/7245K24
Thank you.
It does sound like the problem is the start capacitor - it will do no harm to change it and it's a simple fix.
No idea where you would get one, but most towns, never mind larger cities will have someone who fixes motors for a living and like as not they will be happy to sell you the part you need too.
Appreciate the reply. Thx. Will try.
I get my odd electronic parts from electronics surplus stores, there are a few in Toronto. https://www.a1parts.com/starter/starter.htm
Perfect. Will check this out. Thx.
Just a follow-up. Unfortunately replacing the start capacitor did not work. The motor still starts and runs fine when belt is not engaged with the blade/pulley. The blade/pulley also spins freely by hand when not engaged with motor. As soon as I attach belt, the motor hums and will not start or trips the switch. Think I may need a new motor?
Sorry to hear it didn't work.
The next thing I'd check is the bearings - both saw and motor. You verified they spin freely when not under belt tension but how about with a normally tensioned belt (with the saw unplugged)? Can you spin the fully tensioned belt by hand?
If the bearings check out, I'd double check everything about the new start capacitor - especially the value in Micro Farads (written as MFD or uF) and that the connections are solid.
The centrifugal switch could be dirty or malfunctioning. It's on the inside of the motor and is responsible for disconnecting and then reconnecting the start capacitor (and winding) with each run cycle. If your motor is of the open-frame style, shooting compressed air through it can dislodge sawdust. If your motor is totally-enclosed, it usually requires complete disassembly to get at the switch.
If at any time during these troubles the motor became hot enough to damage the start winding, it will need rewound or replaced.
And finally, what about the RUN capacitor. I have never had one fail on my equipment so I have no personal experience but I Googled it and found some HVAC websites that said a bad run cap can exhibit the same symptoms as a bad START cap. Can anyone on this forum tell us what their tool did when the run capacitor failed?
Mike
Thx for the reply and additional troubleshooting recommendations Mike. Yes I can spin the fully tensioned belt by hand when power is off. I tried a 2nd replacement / new start cap and same results. I will see if I can get at the centrifugal switch you note. Steve
I wouldn't worry too much about the centrifugal switch at this time, it's role is simply to disengage the start capacitor and doesn't come into play until the motor starts. If it is bad it would result in blown Capacitors but it sounds like yours has never started.
Your problem is likely one of 2 things, a bad run capacitor, a run capacitor is a stronger better built capacitor designed to remain in the circuit to increase the efficiency of the motor as opposed to the start Capacitor which is cheaper and weaker and must be disengaged by the centrifugal switch or be destroyed, or an internal short or grounding of the stator. There is also a possibility that bad bearings could be at play here since the problem only develops when there is tension on the belt. A bearing that had too much play could allow the rotor to short against the stator.
I don't know your comfort level with disassembly and testing of these various components but almost everything can be tested if you have a decent multimeter and or visually.
Capacitors that a bulging or leaking are obviously bad, they can be tested electrically with a multimeter meter, just be sure the tool is unplugged and you drain the capacitor first. You can drain the capacitor by shorting the 2 terminals with an insulated screw driver, you should get a shower of sparks. BE VERY CAREFUL capacitors store a tremendous amount of energy and can kick you on your ass if you are careless. Short the terminals 2 to 3 times to be sure. Once the capacitor is drained set your meter to the capacitance setting if so equipped, basic meters probably won't have this, you should get a reading that is within the range printed on the capacitor, if not the capacitor is bad. If your meter does not have the ability to test capacitance then set it for Ohms(if you have ranges use the highest setting) this test is less informative but better than nothing. When you touch your probes to the terminals you should see the value increase as the capacitor stores energy supplied by the meters battery, if it is negative or 0 reverse the probes on the terminals, negative numbers indicate a discharge. If it remains 0 the capacitor is likely bad. The problem with this test is while it shows that the capacitor is storing energy it doesn't indicate if it is operating in the proper range so there is still a chance the capacitor is bad but I would look elsewhere first. If further testing and examination found nothing I would then replace the capacitor.
Blacken areas on the stator or rotor indicates arcing. If arcing is present is it caused by a problem with the windings or are worn bearings simply allowing the the rotor to make contact? If the arcing is with the case its probably the windings if it is between the rotor and stator suspect the bearings especially if there are indications of wear. An ohmeter can also test for conductivity between the windings and the case, a very low value or 0 indicates a short.
The old motors Delta used were pretty solid and usually worth repairing if you can or take it to a pro for their opinion.
Good aft esch5995. Thx for above. Removed some of the casing and the centrifugal does engage/disengage; although to you pt likely was not the issue. I had an friend of mine test the new start capacitor, as well as start switch and all looks good. It runs under no load (no pulley) and will run if I fully engage pulley once started (lifting motor to relieve pulley tension for a few seconds for it to get up to speed). Start capacitor has been replaced. Wondering if it could be the run capacitor? Otherwise, it's an enclosed motor so would need to take it in for repair or to replace.
I have had a motor that acted like this. Some of its windings were shorted out, but it still ran under no load. As soon as you loaded it, its puny nature showed up. In my case, it also sounded different, with a slight hammering sound.
I assumed from the original post, that "However, when I engage the motor with belt (pulley/blade) it trips the motor after a few seconds of trying to start." meant that the motor shaft started to turn, but then the motor overload system shut it off. The fact that the motor trips in a few seconds means to me that there is excess current even for the initial start-up, where the motor and protective circuit expect higher amps. Almost certainly a burnt wiring problem. Unfortunately! It is much harder now than 40 years ago to find someone to rewire a motor. I'll add that I don't know the symptoms of a burnt run capacitor. If it is shorted out, that could possibly cause excess current flow. A motor repair shop could advise on that.
Thank you JHarveyB - I had an friend of mine test Ohms and all looks good. It runs under no load (no pulley) and will run if I fully engage pulley once started (lifting motor to relieve pulley tension for a few seconds for it to get up to speed). Start capacitor has been replaced. Wondering if it could be run capacitor.
Thanx for this information i found mine was same issue
check out your capacitor numer
or check this https://electronicshacks.com/how-to-read-a-capacitor/
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My test to determine no-run fault, motor or capacitor is spin the motor in normal direction of rotation is it runs replace the capacitor.
f the capacitor code consists of numbers and letters, the first two digits of the code will represent the capacitance value. Most capacitors will have a three-digit code printed on them. The first two digits are the value and the third digit is the multiplier.
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