Next couple of days are gonna

[Peanut]

@Supervisor42 No doubt! ... Mouser and digikey are like Radio Shack for professionals. I've done business with both for almost 30yrs. Last time about a decade ago when I was building hydrogen generators. Don't imagine they've changed a lot since then.

 

[Bacpacker]

I order parts from both of them on a regular basis. Another good supply house for electronics is Newark. For general type stuff you can't beat McMaster Carr

 

[Frodo]

Do you think I could find this motor?
18 14831E
396505-03

Dewalt 18 V motor

 

[Wingnut]

Well, Frodo, at least ya know what the problem is... and ya have a dollar amount for the repair.

You done went and let the smoke out of it....
Very common failure point. I blew one a few years back. Probably not a bad idea to keep a spare or 3 on hand

What usually causes this sort of discharge? Condensation? Refresh my memory: capacitors store an electrical charge, right? And it looks like Frodo's capacitor discharged that stored electricity, nearly causing a fire. What other reasons might there be for a capacitor to fail like this? Or discharge at the wrong time? Can a capacitor be faulty by itself?

You electricians bear with me, it has been awhile since I dealt with capacitors... just wanna learn a bit more about 'em.

 

[Frodo]

Well, Frodo, at least ya know what the problem is... and ya have a dollar amount for the repair.



What usually causes this sort of discharge? Condensation? Refresh my memory: capacitors store an electrical charge, right? And it looks like me thing Frodo's capacitor discharged that stored electricity, nearly causing a fire. What other reasons might there be for a capacitor to fail like this? Or discharge at the wrong time? Can a capacitor be faulty by itself?

You electricians bear with me, it has been awhile since I dealt with capacitors... just wanna learn a bit more about 'em.

Wondering the same thing
If it is in fact condensation
Perhaps I need to address the pitch of the unit

 

[Peanut]

@Wingnut Caps separate two charges. The most common failure is the insulator between the charges fails. Basically they short.

In my experience dirty power, (transient voltage spikes) in circuitry will 'wear out' a cap over time and cause them to fail early. Think of a cap as a dam blocking a river, a voltage spike causes it to lose a pebble. another spike then another pebble... one day it loses the pebble that causes the rapid collapse, you end up with a charred mess sooner than expected. They last longer with clean stable power.

I'd want to see how dirty the power is in the A/C unit. It may be a weak component elsewhere in the system causing big voltage spikes, like a fan turning on. A small spike is expected when a fan kicks on... a big spike... no.

Here's a basic description

https://www.electrocube.com/pages/why-capacitors-fail-technical-bulletin

 

[Wingnut]

Peanut, you da man as always! Thank you, I hope that info also helps Frodo!

 

[Frodo]

@Wingnut Caps separate to charges. The most common failure is the insulator between the charges fails. Basically they short.

In my experience dirty power, (transient voltage spikes) in circuitry will 'wear out' a cap over time and cause them to fail early. Think of a cap as a dam blocking a river, a voltage spike causes it to lose a pebble. another spike then another pebble... you end up with a charred mess sooner than expected. They last longer with clean stable power.

Here's a basic description

https://www.electrocube.com/pages/why-capacitors-fail-technical-bulletin

Lotta info
Unit was installed in 2015
8 years is not really
That long of a time

 

[Magus]

Wondering the same thing
If it is in fact condensation
Perhaps I need to address the pitch of the unit

Put a surge box in.

 

[Peanut]

At 8 yrs it might have died at the expected time. The Ac doc will know if this is a normal failure.

I had a hvac school in the navy but that was 35yrs ago. I'm sure things have changed!

 

[Supervisor42]

@Wingnut Caps separate two charges. The most common failure is the insulator between the charges fails. Basically they short.
In my experience dirty power, (transient voltage spikes) in circuitry will 'wear out' a cap over time and cause them to fail early. Think of a cap as a dam blocking a river, a voltage spike causes it to lose a pebble. another spike then another pebble... one day it loses the pebble that causes the rapid collapse, you end up with a charred mess sooner than expected. They last longer with clean stable power.
I'd want to see how dirty the power is in the A/C unit. It may be a weak component elsewhere in the system causing big voltage spikes, like a fan turning on. A small spike is expected when a fan kicks on... a big spike... no.
Here's a basic description

https://www.electrocube.com/pages/why-capacitors-fail-technical-bulletin

2 things come to my mind:
1. It could likely be the manufacturer 'pinching-pennies' and choosing the smallest one that will run the motor. One that is worked near 100% of it's capacity will run hotter. We found that installing one with more micro-farads solved frequent failure problems.
From Peanut's link above:

SERVICE LIFE​

The service life of a capacitor must be taken into consideration. The service life decreases as the temperature increases.

2. As a capacitor ages over time, it's capacity is reduced.
See above for the solution.

 

[winds-of-change]

Before I got my evaporative cooler, I would spend the warmer parts of the really warm days in public places, like libraries, that had AC. It saved me. When I get really warm, I just take lots of involuntary naps. Taking cool showers before bedtime and not drying off is another way to cope. Wake up in the night from the heat? Take another shower. I remember in college, on a really warm day, taking 5 showers in one day to help cool off.

I couldn’t afford air conditioning when raising my kids. We spent a lot of time in the library, malls, stores, etc like you mentioned.

 

[montanabill]

Correct me if I am wrong but my understanding of capacitors on motors is to aid in starting. the stored charge in the capacitor helps the motor get going when it needs three times the power it does to run in a steady state. Well pumps are also known to blow a capacitor and the well goes off........much worry and then someone diagnoses the 30$ problem.

things that go up in smoke is the reason I have smoke detectors in my house over things that could cause a fire. I have one over the clothes dryer and water heater and by the fuse box.

It's getting hot here in montana, going into the 90's but still down in the 50's at night with the humidity at 20% or less.

 

[Supervisor42]

Correct me if I am wrong but my understanding of capacitors on motors is to aid in starting. the stored charge in the capacitor helps the motor get going when it needs three times the power it does to run in a steady state. Well pumps are also known to blow a capacitor and the well goes off........much worry and then someone diagnoses the 30$ problem.

things that go up in smoke is the reason I have smoke detectors in my house over things that could cause a fire. I have one over the clothes dryer and water heater and by the fuse box.

It's getting hot here in montana, going into the 90's but still down in the 50's at night with the humidity at 20% or less.

They actually work as a 'slip clutch' on many motors that only have only one capacitor.
When the circuit turns on and the motor is stalled, it keeps it from flipping the breaker because the motor would appear as a dead-short.
It gives the power 'somewhere else' to go at startup.