Electric guru

[pkunk]

I blew the run capacitor in my 3hp Dust collector today. It was running fine earlier but just groaned and popped the breaker. What can cause this? Should I replace the start capacitor too? Mfg wants $36 plus $10 shipping but I found one online for $13 delivered.

 

[BigCahuna]

I'd try the $13 possible fix, rather then the more expensive unit replacement cost. I replaced the cap in my 18,000 btu air conditioner, and it was alot cheaper then replacing the unit. I watched a bunch of u tube videos and what I gathered from them was, the cap was a common thing to go .,,

 

[Exit32]

In the early-to-mid 2000s, there was a bunch-of-junk batch of imported capacitors installed in all kinds of consumer products Those cheap caps have been failing for a few years now. Looks like your blown cap was manufactured in February, 2006, so it probably came from the bunch of junk.

I'd replace it using a capacitor with the same rating: 50 microfarads and 250 volts AC. You can use a cap with a higher voltage rating, but stick with 50 microfarads of capacitance. There's no polarity on an AC capacitor, so it doesn't matter which lead goes where.

It's likely the start capacitor is also cheap, imported part. I'd replace that one at that same time.

 

[WyrTwister]

Capacitors are a common failure point on single phase motors and HVAC equipment . Capacitor went out on our living room mini split . Next day I went to Johnstone Supply and purchased a 370 VAC replacement capacitor . That got it running again . Praise the Lord !

I would go ahead and purchase the 2nd capacitor . Might just wait until that one goes out , to swap in the new capacitor .

Be very careful . Turn the power off , first . Good capacitors can hold a charge for some time . Use the end of your screwdriver and shorty across the 2 terminals to discharge any charge still holding in the capacitor .

 

[pkunk]

Capacitors are a common failure point on single phase motors and HVAC equipment . Capacitor went out on our living room mini split . Next day I went to Johnstone Supply and purchased a 370 VAC replacement capacitor . That got it running again . Praise the Lord !

I would go ahead and purchase the 2nd capacitor . Might just wait until that one goes out , to swap in the new capacitor .

Be very careful . Turn the power off , first . Good capacitors can hold a charge for some time . Use the end of your screwdriver and shorty across the 2 terminals to discharge any charge still holding in the capacitor .

The hole in that one let all the juice out-no worries.

 

[pkunk]

In the early-to-mid 2000s, there was a bunch-of-junk batch of imported capacitors installed in all kinds of consumer products Those cheap caps have been failing for a few years now. Looks like your blown cap was manufactured in February, 2006, so it probably came from the bunch of junk.

I'd replace it using a capacitor with the same rating: 50 microfarads and 250 volts AC. You can use a cap with a higher voltage rating, but stick with 50 microfarads of capacitance. There's no polarity on an AC capacitor, so it doesn't matter which lead goes where.

It's likely the start capacitor is also cheap, imported part. I'd replace that one at that same time.

The mfg website has a replacement one but says it's 600mfd 125V. It's a 240v machine. I see lots of 600mfd caps that will fit. I guess 125V is OK?
Mfg pic

 

[AandPDan]

No 125 volt is not okay. You can go higher but not lower voltage.

You have to match the farad's.

That shows a starting capacitor. They are not the same.

 

[JimPghPA]

OP, read what Exit32 and AandDan told you.

1) You have to stay with the same MFD number.

2) You can use a new capacitor with a higher Voltage number, but you can NOT use one with a lower Voltage number.

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The second capacitor you posted a picture of fails to meet both of those requirements. It is NOT the same MFD so it will not work. AND the Voltage rating is not the same or higher than the original so it will not work.

 

[pkunk]

That second one is the start cap. It was suggested that I replace it. That pic is from the mfg website as their replacement. I ordered the correct run cap already.

 

[pkunk]

Here's a possible replacement start cap.

 

[pkunk]

This pic is the mfg replacement for the run cap. I ordered this-Run Capacitor CBB60 450VAC 450V AC 60uF 60 uF 60MFD , 50/60Hz

 

[berniedd]

Er, what is the difference between a run capacitor and a starting capacitor if both have the same ufd and voltage rating? They are not interchangeable?

 

[Lubener]

This pic is the mfg replacement for the run cap. I ordered this-Run Capacitor CBB60 450VAC 450V AC 60uF 60 uF 60MFD , 50/60HzView attachment 28286

That will be fine.

 

[Lubener]

Capacitors are a common failure point on single phase motors and HVAC equipment . Capacitor went out on our living room mini split . Next day I went to Johnstone Supply and purchased a 370 VAC replacement capacitor . That got it running again . Praise the Lord !

I would go ahead and purchase the 2nd capacitor . Might just wait until that one goes out , to swap in the new capacitor .

Be very careful . Turn the power off , first . Good capacitors can hold a charge for some time . Use the end of your screwdriver and shorty across the 2 terminals to discharge any charge still holding in the capacitor .

Yes by all means make sure the cap isn't still holding a charge. However, If a capacitor holds its charge "in circuit" for a long time there is usually another issue within that circuit as there will be a path for discharge within the circuit. An open circuit from a failure will not provide that discharge path.

 

[spackard]

Er, what is the difference between a run capacitor and a starting capacitor if both have the same ufd and voltage rating? They are not interchangeable?

Run cap lower capacitance and going to deal with more heat. The thing's going to be charging and discharging many times a second,
for hours. Start cap only has to do a few seconds' duty cycle.