Help with motor capacitor

Barncat

Barncat

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I would like to use this motor but it is missing a capacitor. I am used to seeing two capacitors on motors, but this only has a spot for one. Is there a start/run combo capacitor that I should be looking for? Or is something else going on here?1B2DE166-9D33-4645-8303-57A942CFDE16.jpeg
 
Many motors use just a single start cap. For that one I would guess something like 400-475 microfarad (uF) at 250 volts would work
although if it has to fit under a cover you might could go a bit lower on the voltage rating - 125 volts would be the absolute minimum
which would reduce the diameter enough that it might fit in the space provided- but use the highest voltage cap you can fit
(you can mount the cap separately- it doesn't need to be mounted on the motor, you can extend the wires)
www.ebay.com

TEMCo 400-480 uf/MFD 165 VAC volts Round Start Capacitor 50/60 Hz -Lot-1 | eBay

TEMCo ID: SC0098. Uf (mfd): 400-480. "I have always been delighted with the service from TEMCo. About TEMCo. Frequency: 50/60 Hz. Format: Round. Country of Manufacture: United States. Temperature range: -40 to +65°C.
www.ebay.com

www.ebay.com

TEMCo 430-516 uf/MFD 220-250 VAC volts Round Start Capacitor 50/60 Hz -Lot-1 | eBay

TEMCo ID: SC0001. Uf (mfd): 430-516. "I have always been delighted with the service from TEMCo. About TEMCo. Frequency: 50/60 Hz. Format: Round. Country of Manufacture: United States. Temperature range: -40 to +65°C.
www.ebay.com
 
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I would go with a higher voltage rating, e.g. 350 vac. If your intent is to ever run the motor on 240 volts, even a 250 vac. capacitor will be marginal. If you don't have the OEM cover, a simple strap can fix the capacitor to the motor housing.
 
With the 240 volt case the starting leg never sees more than 120 v due to the voltage divider formed by the series connected run windings.
Also, the price starts to skyrocket with voltage ratings over 250
Of course it's preferable to have some overhead, but I have seen many overseas motors supplied with 125 volt rated start caps and
they seem to give a good long lifetime, several years in most cases, sometimes a decade or more.

The one in my bandsaw has a datecode of '77- still soldiering on
 
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Why does it not show where the cap is connected in the wiring diagram? Are there leads that are not shown?
 
rwm said:
Why does it not show where the cap is connected in the wiring diagram? Are there leads that are not shown?
Click to expand...
Capacitors are not usually shown in the motor wiring legend.
T5 and T8 are generally used as the start winding
 
T5 and T8 usually represent the whole start leg which is the start winding, the start cap, and the internal centrifugal start switch

100-150 uF would probably start it- as the value drops the starting cycle takes longer and has less torque during the start
Once the motor is up to speed it has full power, but if the start cap is too small it will never reach full speed if there is any load
 
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markba633csi said:
With the 240 volt case the starting leg never sees more than 120 v due to the voltage divider formed by the series connected run windings.
Also, the price starts to skyrocket with voltage ratings over 250
Of course it's preferable to have some overhead, but I have seen many overseas motors supplied with 125 volt rated start caps and
they seem to give a good long lifetime, several years in most cases, sometimes a decade or more.

The one in my bandsaw has a datecode of '77- still soldiering on
Click to expand...
My error. I was thinking about run capacitors when I made my post.
 
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