Delta Rockwell band saw motor will not start

There may be some motors that use the run windings for starting but it's rare to see that. Most made from the 50s onward using a start capacitor
have 2 run and 1 start winding. Some are called split-phase; they don't have start capacitor, only a centrifugal switch. They work well in applications where high starting torque is not required.
I went for years without any type of capacitor meter, but recently bought one of those little imported circuit board units that runs off a 9v battery.
It measures caps, inductors and semiconductors with pretty good accuracy and only cost around 7 bucks. Highly recommended, and I'm a tightwad when it comes to buying test gear
Here it is:
www.ebay.com

LCR-T4 ESR Meter Transistor Tester Diode Triode Capacitance SCR Inductance M328 714890585287 | eBay

Inductors, capacitors, diodes, dual diode, mos, transistor, SCR, the regulator, LED tube, ESR. diode (including double diode), thyristor, transistor, resistor and capacitor and other components. 3:Can detect the transistor, MOSFET protection diode amplification coefficient.
www.ebay.com

-Mark
 
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My simpson meter is great for testing capacitors.
you can watch the cap charge up and then watch the needle drop
a bad cap won't charge, the needle won't swing
 
MikeInOr said:
You do not need to get a new capacitor with an exact 216-259MFD rating. Any capacitor around 180MFD to 300MFD with the same or higher voltage rating will do the job just fine
Click to expand...
Just for kicks I went down to Ace Hardware in town.
They actually had one capacitor in stock. The value was, 124-149uf. I understand uf and mfd are the same thing?
Based on what you said, I don't think Ace is gonna help me.
 
Janderso said:
Just for kicks I went down to Ace Hardware in town.
They actually had one capacitor in stock. The value was, 124-149uf. I understand uf and mfd are the same thing?
Based on what you said, I don't think Ace is gonna help me.
Click to expand...

uF is microfared, mF is millifarad which equals 1,000 uf.

If they are both starting capacitors that doesn't sound quite right. Most starting caps I have used are within 100% to 300% or so of each other across a very wide range of motors. They generally won't be different by a factor of more that 1000. Can you post a pic of the writing on the old capacitor?
 
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Ulma Doctor said:
I have seen Microfarads expressed as mf on older capacitors.
Don’t confuse with milli-farad
Click to expand...

Yes, microfared for a starting capacitor makes much more sense to me! I had actually posted that the substitution looked good to me until I looked it up to make sure.

WIKIpedia:
For most applications, the farad is an impractically large unit of capacitance. Most electrical and electronic applications are covered by the following SI prefixes:

  • 1 mF (millifarad, one thousandth (10−3) of a farad) = 1000 μF = 1000000 nF
  • 1 μF (microfarad, one millionth (10−6) of a farad) = 0.000 001 F = 1000 nF = 1000000 pF
  • 1 nF (nanofarad, one billionth (10−9) of a farad) = 0.001 μF = 1000 pF
  • 1 pF (picofarad, one trillionth (10−12) of a farad)
 
Oh microfarads is what you need for sure. Another tip off for the right part is size. If a vendor tries handing you one that's 5x bigger or 10x smaller than the old one, nope.
 
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Well shoot.
I replaced the start capacitor and it just hums, tries to decide which direction to turn then goes to full speed. This takes a couple seconds. One time it turns clockwise, the next counter clockwise.
Now what?
I replaced it with an identical start capacitor.
 
Check your connections. Did maybe a wire slip out from under a wire nut? It could also be dirty or pitted starting contacts.
 
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