kellogg 331 motor buzzing

[stage20]

kellogg 331
5hp unknown brand sealed, fan cooled motor.
i assume its only a start capacitor gone bad. should i replace one, or both? one is missing, ive already removed it to get information off of it. not sure if its an electrical issue or just a bad cap. round ones are start capacitors and the oval ones are run capacitors? im only saying this because one of the small round ones the top has opped off. they are dated 2003 ive had the compressor since 2013 problem free.

 

[nadogail]

kellogg 331
5hp unknown brand sealed, fan cooled motor.
i assume its only a start capacitor gone bad. should i replace one, or both? one is missing, ive already removed it to get information off of it. not sure if its an electrical issue or just a bad cap. round ones are start capacitors and the oval ones are run capacitors? im only saying this because one of the small round ones the top has opped off. they are dated 2003 ive had the compressor since 2013 problem free.

Replace the cap where the "fop has opped off"; then check again.

 

[stage20]

in a pickle.
looked everywhere online and every electrical shop local and catn find a correct cap.
the cap is 590-708mfd with a 165vac rating.

grainger and johnstone supply tell me if i use a 110-125v cap i will blow it up. said i need to go up in voltage, but i cannot find a cap in my mfd range that is 220/230v.

should i gamble with a 125v rated cap? i really have no choice. maybe this manufacture rated the cap up to 165v and my motor doesnt require it?

 

[md21722]

You must have the volts

You can use caps half the MFD wired in parallel too.

 

[md21722]

Is this what you need?

https://www.ebay.com/itm/321492907405

 

[nadogail]

Capacitors in parallel add their MFD rating, that is two 100 MFD Capacitors connected in parallel become a 200 MFD Capacitor; Capacitors in series add their voltage ratings, two 300 volt Capacitors connected in series become a 600 volt capacitor.

With a little creative thinking and a bunch of AC Capacitors, a series parallel combination can that created that will be equivalent to any starting or run capacitor.

 

[nehog]

C... Capacitors in series add their voltage ratings, two 300 volt Capacitors connected in series become a 600 volt capacitor.
...

Series capacitors result in a capacitance value as defined in this formula:


Ct = (1/C1) + (1/C2)+(1/C3)...(1/Cn)

Where

Ct is final total capacitance value
C1... Cn is each capacitor. Notice that capacitor values do not have to be identical.

So two 50 mf capacitors in series would become:

25 = 1/0.04 = 1/50 + 1/50

If you need a non-polarized capacitor, and don't have one, you can use two polarized capacitors, connected back to back, using the above formula to determine the value. However, this configuration will not increase the voltage ratings.

 

[stage20]

You must have the volts

You can use caps half the MFD wired in parallel too.

i know the caps store energy, but i am not educated on how the voltage works.
this motor has 2 start capacitors, and is a 230v motor. if each cap is 125v, that is rated higher than the nominal voltage?

 

[stage20]

Is this what you need?

https://www.ebay.com/itm/321492907405

negative.

exactly this part down to the size and shape, minus the 125vac rating.

 

[stage20]

Series capacitors result in a capacitance value as defined in this formula:


Ct = (1/C1) + (1/C2)+(1/C3)...(1/Cn)

Where

Ct is final total capacitance value
C1... Cn is each capacitor. Notice that capacitor values do not have to be identical.

So two 50 mf capacitors in series would become:

25 = 1/0.04 = 1/50 + 1/50

If you need a non-polarized capacitor, and don't have one, you can use two polarized capacitors, connected back to back, using the above formula to determine the value. However, this configuration will not increase the voltage ratings.

i will have to do some research on the polarizing. the one cap i pulled out has a resister on it, i didnt pull the other. not sure if both caps have resistors, or only the one that is blown.

 

[dave*99]

Series capacitors result in a capacitance value as defined in this formula:


1/Ct = (1/C1) + (1/C2)+(1/C3)...(1/Cn)

Where

Ct is final total capacitance value
C1... Cn is each capacitor. Notice that capacitor values do not have to be identical.

Fixed it for ya.

 

[justsam]

negative.

exactly this part down to the size and shape, minus the 125vac rating.

The cap shown is rated at 250 volts. Better than the one you are replacing.

 

[md21722]

i know the caps store energy, but i am not educated on how the voltage works.
this motor has 2 start capacitors, and is a 230v motor. if each cap is 125v, that is rated higher than the nominal voltage?

You need to use ones rated for minimum 230V. There is no harm in going higher. The link I provided should be all you need. When using two caps with the same capacitance, add capacitance when wiring in parallel, or half them in series. If you use different sized caps, then you need to use the formuals the other posters provided.

 

[stage20]

The cap shown is rated at 250 volts. Better than the one you are replacing.

i dont know why this link didnt show up in the first post.

this is the cap i need, but wrong voltage. mine looks exactly like this.
http://www.ebay.com/itm/Start-Capac...516868?hash=item3cca0758c4:g:ccUAAOxy8hNRjWu1

 

[Joe L. Ohmer]

nehog: any formula for cap size for fastest start>