praise where it's due

Excellent!

John K Jordan

That's good to hear. I love it when I can get something running again with minimal pain.

Your story is encouraging after my experience a few years ago. The capacitor on one of my mini lathes failed while at a kid's turning program. Jet charged me over four times the typical cost of a capacitor for that size of motor. I thought about just installing a locally off-the-shelf cap but it was a little bigger diameter and I would have had to devise a new can to cover it. To be fair, maybe Jet had used a special, hard-to-get part on that lathe.

I prefer to think, though, that they've rethought their customer service policies and the future is rosy! 👍

JKJ

Sideways hijack, Some tune, different verse

Barry Irby

Glad to hear Jet was responsive, let us know about the new cap...

I am working on a Condo I am flipping....it had a Federal Pacific Stab-loc panel. Bad news, they are out of business and the parts are expensive and hard to get so I decided to replace it. Bought a Square D panel and needed a GFCI breaker. Lowes had every other kind of breaker, AFCI and Combo ones and on and on, but no GFCI. I went to Lowe's twice on different days and could never find a knowledgeable person in the electrical aisle. Frustrated, I called Square D from Lowes and asked the Tech if they even made a GFCI. He gave me the catalog number and then said if Lowes did not have it Home Depot would. There is a Home Depot about a mile up the street and on my way. Went there and got the breaker. Square D/Schneider was polite and more helpful than either of the stores. Thank you Square D.

Re: praise where it's due

mikeee12345

All capacitors have a useful operating life and will fail over time, the insulating materials used inside the capacitor will over time break down and fail. Certain types of capacitors if left sitting for long periods of time need to be re-conditioned prior to using them or they run the risk of failure on start up.

reconditioning capacitors

John K Jordan

>>>Certain types of capacitors if left sitting for long periods of time need to be re-conditioned prior to using them...

What types of capacitors and what type of reconditioning?

I know about reforming electrolytic capacitors to recreate the internal thin layer of aluminum oxide but those are polarized capacitors for DC operation. I thought all motor run and start capacitors were non-polarized, for AC use. ??? Educate me, please!

The motor capacitors I've experienced failing did so with gusto, with a strong odor when the capacitor overheated while in use and the containment failed, spectacularly so on my Rikon bandsaw.

JKJ

Re: reconditioning capacitors

mikeee12345

We have a large number of various sizes and types of capacitors at the Biorefinery campus I work at which requires periodic preventative testing to prevent unplanned outages for the facilities on site. The larger AC capacitors on medium voltage and low voltage systems undergo several periodic tests to assure they are in proper operating condition. We have a number of spare capacitors that we stock in inventory that are dated when they come in and undergo reforming if they are to be installed and put into use. We also have a number of spare VFD's that have internal capacitors on board that also undergo a reforming process when they are pulled off the self and have an older date of manufacture prior to being put into use. Depending on the size and type of capacitor determines the tests that we perform. YouTube has a number of videos that show basic testing and reforming methods that can be employed. Years ago one of our facilities had a 4160V oil filled capacitor fail while in use causing a sizable blast and considerable smoke damage in an electrical motor control room, the carbon left behind covered every square inch of the room and is very time consuming and expensive to clean up once the incident occurs.

Re: reconditioning capacitors

John K Jordan

Do you have any quick advice to the average hobbyist woodturner on some reasonable test or maintenance procedure that may help for AC capacitors, something that doesn't require specialized equipment?

Or does the average turner just need to wait until the cap fails? Or perhaps have a spare on hand to avoid down time.

JKJ

Re: reconditioning capacitors

mikeee12345

Care must be taken when working with capacitors as they can hold a sizable electrical charge that can be painful if not handled with care. For small motors and appliance type capacitors they do make a capacitive meter that measures the capacitive value which can be compared to the value marked on the capacitor. A multimeter can also be used to perform several basic tests on the capacitor. You can use a continuity test to check between the metal case of the capacitor and each terminal for a shorted (bad) capacitor. A good capacitor will not indicate any continuity between the metal casing and the capacitor terminals. You can also use a continuity check across both terminals which should indicate an increase on the scale and then fall back to a zero value. This indicates the capacitor is charging and discharging when the meter value rises and falls back to zero, the capacitor is using the voltage from the meter to charge with. You can also momentarily touch 120v of power across the terminals of the capacitor to charge it and then use an insulated conductor like a screw driver to short the capacitor, if a spark jumps across while shorting the terminals the capacitor is usually working fine. A visual inspection of the capacitor can also provide an indication of the condition of some types of capacitors. Any fluids leaking from a sealed capacitor or the swelling of the capacitor enclosure is usually a sign of the end of life nearing for the capacitor.

Re: reconditioning capacitors

Rod Peterson--Ormond Beach, FL

There's a guy on YouTube (Mr. Carlson's Lab) who has discussed extensively on the very subject of capacitors and their failures. Worth a look. It's obvious very quickly he knows what he's talking about.

https://www.youtube.com/user/MrCarlsonsLab/videos

Thanks, Rod

GaryG in MD

I always enjoy such things. ...GG

Re: reconditioning capacitors

John K Jordan

There's a guy on YouTube (Mr. Carlson's Lab) who has discussed extensively on the very subject of capacitors and their failures. Worth a look. It's obvious very quickly he knows what he's talking about.

https://www.youtube.com/user/MrCarlsonsLab/videos

Do you know if he specifically discusses motor capacitors? I tried searching his videos but couldn't see that. Some highly interesting stuff, though.

JKJ

Re: Mr. Carlson's Lab

Rod Peterson--Ormond Beach, FL

> Do you know if he specifically discusses motor capacitors? I tried searching his videos but

> couldn't see that. Some highly interesting stuff, though.

Not that I recall, John. However, I haven't seen all of his videos. It takes somewhat of a commitment of time, as they are frequently nearly an hour long (several over an hour, and he has at least one that's nearly 3 hours). The ones in which he discusses capacitors the most are the old pieces, dating as far back as the '30s, but also as recently as the '50s. The discussion involves leakiness (which actually isn't what one would think), and the various types. Paper capacitors are the biggest culprits, which is probably a long way from a start capacitor.

Rod

Re: Mr. Carlson's Lab

John K Jordan

Thanks. I'm fairly familiar with various types and problems with capacitors in general, but know very little about start and run capacitors with regards to motor operation.

(break, replace )

Maybe I'll call up my friend Joe. He knows everything.

Old capacitors

Bill Howatt

Comment about the capacitors being older ones from the 30s being healed makes sense. In those days the electrolytic capacitors were called "wet" capacitors and they could go bad from long periods of non-use. From what I recall an old radio repair man telling me in the late 50s the solution was to apply a low voltage to them and then gradually bring it up. This reformed the dielectric between the plates.

If you have a modern dud capacitor even if it is an electrolytic I doubt if you can do much to repair it and other dielectrics such as paper, mylar, ceramic etc would be even much less likely.

Basic motor capacitors usually are electrolytics made to handle AC. You can make an AC electrolytic by putting 2 capacitors in series with the 2 + or 2 - terminals connected together. On each half of the cycle the wrong polarity capacitor presents a low impedance to the current. Proper motor capacitors I believe have more factors in their design to give them better life than this trick alone.

Bill

Re: Old capacitors

Bill Boehme

You're making me all nostalgic. I became all consumed with radio when I was still in elementary school thanks to a guy that lived down the street who did radio and television repair on the side. My life's ambition was firmly set at age 12 ... I was going to be a radio repairman. Not anticipating the demise of vacuum tubes and the semiconductor revolution which ushered in the throwaway society, I had to scrap those plans and settle for becoming an electrical engineer instead.

But, I digress. In the 1960's when vacuum tubes, big heavy power transformers, and wet film electrolitics were still roaming the earth, I built a device for forming the dielectric on those capacitors before installing them in a radio or television set. It was really very simple: a 25 watt light bulb, a light socket, a switch, a lamp cord with plug, a couple test leads with alligator clips, and a selenium rectifier all mounted in a cigar box. If you had money to splurge on safety you could include a 1 Meg ½ watt bleeder resistor. Those were the days.

now you're making me nostalgic too

GaryG in MD

I got my ham ticket in '57 at age 14.

My friends and I used to run home from Jr. High so we could talk on the radio!

Kind of like the texting of our era.

I loved building circuits. Luckily, not all of them worked -- like the plasma torch I attempted.

Thankfully it wouldn't oscillate or I might not be telling you about it now.

When I got to college, I took "Circuits" (vacuum tubes, of course) instead of M&G, which is why I had to ask my friend how induction motors work so I could tell Doc Green!

I worked in the computer center as a freshman.

One of my jobs, in addition to emptying card punches and trucking card decks around on a trolley, was to change a few tubes (12SN7s, I think) every morning in the University Computer -- an IBM 709! They always blew a few when they turned it on in the morning. They couldn't let it run overnight because they couldn't afford the electric bill for keeping the filaments on.

The next year we got the IBM 7094 -- same one as in the movie Hidden Figures. (We didn't have a problem getting it thru the door.) :-)

Yeah, those were the days, indeed.

Nostalgic; Amazing the changes over our lifetime

Keith Newton

I love hearing about some of the background stories from some of you guys. The collective wisdom from this fellowship is just incredible. I had to laugh when Bill said he had to "scrap those plans and settle for becoming an electrical engineer instead."

That reminded me of once when we were kids, one of the adults ask my brothers and me what we intended to be when we grew up. I've forgotten what my older brother said, but my brother Wood said he was going to be a doctor. I was the youngest, and probably about 5 at the time. I still remember how hard Wood laughed when I said I wanted to be a lumberjack. In my own defense, I loved that book about Paul Bunyan and his blue ox, which was the first thing that came to mind. In retrospect 65 years later, I kinda have to gloat that I really came closer than he did since woodworking became my career, and he became a songwriter. ha

Re: now you're making me nostalgic too

mikeee12345

Decades ago I picked up an IBM 7090 console and tape drive at a state university auction and turned it into a coffee machine. Eventually the console was gutted and converted into a control panel for a grain handling facility and the tape drive was gutted and converted into an early version of an I/O rack.

Re: now you're making me nostalgic too

John lucas

I was in long range radar when I was in the air force. We had a room about 30 x 40 that was the computer. We spent many hours looking for tubes that had one filament burned out. Before I left they replaced it with a computer about the size of a double wide refrigerator. I'll bet you money the phone I'm typing on now is more powerful than that computer. That was 1972.

tubes and phone

GaryG in MD

The IBM 709 had indicator lights on each rack to show where the tubes with burned out filaments were, so we didn't have to look too hard for them.

I guarantee your phone has thousands (and more) times more capability than that old monster.

...GG

Re: now you're making me nostalgic too

jorge

Gary,

I too grew up with a soldering gun in my hand, made many radios and transmitters and like you had fun talking to my friends. One day in a differential calculus class, I was wearing a hat with a wire shaped like a tv antenna and in my breast pocket had the radio about the size of a pack of cigarrtes. A professor I never seen before, walked in, noticed me and came to investigate, pointing to my knit hat, so I just flipped one of the earphones his way and raised the volume, he stop and open big eyes. How do you do that? I did not explain just said "easy". This was way before transistors and I used a crystal. The fellow was the dean of the school I was and gave me a scholarship for electronics

Re: now you're making me nostalgic too

Bill Boehme

When I was 12 my dad gave me a Weller 8200 for Christmas. For those who don't know, that was THE soldering gun to own. I remember the price was $6 which was a lot back then. It included a carrying case and several accessories. When I was in the local hardware store the other day I noticed that you can still get the Weller 8200, but the price has gone up a bit and it no longer has a Bakelite body. I still use that old soldering gun. One of my best ever Christmas gifts.

Weller 8200: 55 and counting

Doc Green

My first real soldering gun was an 8200 and I have used it regularly for well over 50 years.

Re: Weller 8200: 55 and counting

John K Jordan

Hey, I have one of those!

In the early 80's I bought six Weller professional soldering stations at a tech auction for almost nothing. I was able to make four good ones from the parts. The two I kept are still working today. With thermostatically controlled tips these are amazing for soldering, especially on delicate circuit boards. The 6809 computer I built around then had 1430 solder connections on each 8K static memory board! And has anyone else soldered wires to the millimeter-spaced pads deep in a hole in the back of a digital watch? Good fun!

JKJ

Great story, Jorge!