Condenser fan motor sustitute

Many years ago I ran a vacuum cleaner repair shop. At that time I knew of several motor rewinding shops that repaired all small electric motors.

snipped-for-privacy@nowhere.com fired this volley in news: snipped-for-privacy@4ax.com:

And they've all gone by the wayside. Nobody actually "repairs" anything at the component-level anymore. Everyone is now, what in the 60s in the TV repair business, what we referred to as "tube caddies". They just replace (expensive) components as a full assembly. No actual 'repairs'.

Our (best) local AC company can't even find a technician who can properly find and repair a minor slow-leak of refrigerant on an AC unit. "Oh... you'll need a new condensor unit" is all they can offer.

I can still find and fix them, and I'm not an AC guy. Why can't they?

Why? Because now labor is more expensive than hardware. It's just the way things have evolved.

Lloyd

The starting current might go up (so it behooves you to check the ratings of whatever relay or contactor drives this motor), but operating current will be about the same (because you aren't changing the mechanical load). So, substitute away!

1100 RPM is kinda oddball, but a web search finds the part; Amazon and other suppliers will sell you an identical replacement part, it seems.

Try those folks. I've had very good service from them over the years with small motor rewinds.

whit3rd fired this volley in news: snipped-for-privacy@googlegroups.com:

Not to Stryped. He doesn't LOOK for parts before he asks here to get help finding the parts he never looked for... Heck, he doesn't look for _any_ information before he asks here.

And with deference to you (few) guys who actually know what you're doing, this is the LAST place anyone should ask for good, sound mechanical advice!

Lloyd

Yep! I once had a AC company do a free estimate on my condenser pump that wouldn't start. I told him I suspected the cap and asked him how much to just replace the cap and he had a spare on his truck. He wanted $327 with no guarantee. I waited until Monday and got one from Grainger for $27. What refrigerant are you using in the leaker?

Tom Gardner fired this volley in news:mqohd4$la2$1 @speranza.aioe.org:

R22, and it leaks about a pound or two a year, which may be below the threshold of my equipment (though the specs say it should pick it up).

Last time I pumped it down and re-charged it, I replaced both Schrader valve cores, so it's not _likely_ them (but could be, of course).

More likely is a tiny spec of not-well-done soldering somewhere.

Oh, well... I've got about 28lb of pre-ban R22 still in stock, so if I don't have to pull it down again, technically I've got 14 years worth! (yeah... I know...like THAT will happen! )

Lloyd

I'd have called his boss right then and there to complain. That's outright rape. It may have done no good, but if you successfully weeded just one bad apple out of his company, the boss might have done the job for you for free. It's a freakin' 1/2 hour job and $10 part! (If the boss was him, or boss was OK with it, tell everyone you know)

1) shut off thermostat & throw the switch on the cutout. 2) pop the sheetmetal cover off. 3) map out and disconnect the cap leads 4) short the cap for safety 5) loosen 1 screw holding cap 6) r&r cap 7) replace cap leads 8) reinstall sheetmetal cover 9) throw the switch 10) go inside for cool air.

I happened to be in my Chiro's office when the HVAC guy came around. I asked him if he had a cap for my unit and he brought the $15 invoice and the cap in from the truck 3 minutes later.

Even worse, during an annual maintenance visit I was told that my capacitor was getting weak (True, it was.). I asked how much for a new one and was told $50 for the part and, get this, $70 labor to install it. The guy had the old part out of the machine to measure it. No charge to put the old cap back in the machine, but $70 to do the same thing with a new one. I told him, "No, thanks," and found a seller on eBay that would send me two (2) exact replacements for a total of $15.60 with free shipping. The first of those has been in use for 2 Summers now, with no sign of a problem.

I have three of the new room types - outdoor unit and indoor unit. Two lost refrigerant for a year. Call after call they refilled. I insisted they put in a can of trace colorant and finally they did.

My dear wife then when they ran out again, called a company that worked on the house not on the office. He came out and said he wasn't with that company but would look. Both units had hoses with loose connections. The other company thought they tightened the joints and tried flame and bubbles to locate the leaks. Trace did.

The installing company has yet to call to see if the trace did anything.

The house guy working on the house - put in two cans of material that reduced the acid in the lines. We have high water in the air here.

Mart> Tom Gardner fired this volley in news:mqohd4$la2$1

I was going to mention R-22A which I got a cylinder for $130 delivered. I'm running a mix now because mine loses about 1.5 lbs/yr and after 3 years I have no complaints and it runs lower pressure now.

I have to replace my dual cap every 2 years, why don't they last?

Tom Gardner fired this volley in news:mqrt5r$90r$1 @speranza.aioe.org:

I used to think it was "poor quality work", but I believe now that it's a combination of the impact of "controlled substances" (like PCBs) and deliberate planned-life designs.

Keep in mind that such caps are NOT considered a "user replacable part", so if the electrical components industry can convince the end-user "that's just the life of the part", then both the parts makers and the local service companies benefit by getting more work.

When you add to that scheme the fact that the _right_ materials for building a good (and compact) capacitor are mostly all illegal now, it all seems to make sense.

And yes, they could still make good caps for military and high-end commercial gear, but they usually MUCH larger, and might not fit in equipment designed for the smaller form-factor parts. (plus the exhorbitant prices)

LLoyd

They're pushed within an inch of their lives on voltage rating (Measure the voltage across one some time -- you'll be surprised.), and baked in the sun on hot, Summer days. They would last a lot longer in a more hospitable environment.

Just did that with the outdoor fan motor.. about $13 from the local wholesale supplier for a dual 5uF/40uF 440VAC capacitor, pop it in and ahhh cool air.

The fan motor was getting really hot, but not hot enough to destroy it.

I hate to think what it would have cost to pay some dude to replace the fan motor, probably $1K+ for not much more work. Maybe the price goes up with house size and brand of A/C unit.

--sp

I seem to have to replace mine every 20 years (i.e. once). But the replacement is significantly smaller (had to modify the clamp). That does not bode well.

Actually if this is not just a rhetorical question- the capacitors when used within ratings do not really have a failure mode. They are plastic film capacitors with some gunk to prevent moisture from screwing things up. Unlike electrolytic caps that do have a definite lifetime.

I suspect that what happens is that lighting and other transients causes breakdown that causes a self-healing (because the short blows away) short in the aluminized film. The value of the cap drops with each surge until it's no longer high enough to support the motor operation. The 5uF (?) one in my furnace draft inducer fan was down to something like 1uF when it took out the fan motor (ouch$$$).

They've just pushed the thickness of the film down so far to save money (and the volts/mil does not change) so the caps are more susceptible to overvoltage spikes.

Just a guess.

--sp

Spehro Pefhany fired this volley in news: snipped-for-privacy@4ax.com:

No, being an 'empirical chemist' one of my interests is in how polymers act with time. Storage issues with pyrotechnic compositions containing them is the matter at hand.

Most of the polymers used for the dielectric film undergo slow degradation due to oxygen, chlorine, or sometimes even nitrogen in contact with them.

They also can react (most slowly) to strong electrical fields across them.

In any case, they slowly break down into compounds which are not particularly good insulators, lowering the capacity, and eventually allowing shorts to occur at the rated voltage.

It's not unexpected -- they make them to the BAREST minimums necessary to manage the applied voltage, as it is.

Once, caps were 'over-rated'... no longer. Otherwise, the motor-start capacitor guys would lose that 'replacement market'!

Lloyd

Perhaps you might try going with another brand, and doublecheck with the HVAC mfgr that the cap you're replacing is the correct value for the unit you have.

Hmmm...

Rapists.

Let's see, if a USAF toilet seat costs...

There was an article, a couple of years ago, about substandard capacitors being used in computer mother boards as they were much cheaper. The article stated that a couple of engineers had left a major capacitor making company and set up their own company aimed at selling capacitors at a lower cost and left out some sort of preservative in their capacitors. Whether true or not the latest mother board I've bought had a statement on the box that it had "improved, long life capacitors".