R-22 Heat Pump update

I was able to get a cylinder of R-22 and the right manifold and hoses and finally it was good enough weather to check out the system. Not good! First, the fan on the condenser wouldn't start on it's own but a little push with a screwdriver got it spinning. The bearings seem OK so I suspect the capacitor. Next, the compressor won't start, it just hums for a while then goes quiet then repeats. Hmmmm. The static pressure on the refrigerant is 110 psi on both sides at 70 degrees F ambient.

So, I assume the worst on this 15 yo Trane and it won't be worth fixing. At this point I call in a professional, a nephew of a friend on mine and see what he thinks. I'm a heat baby and like the house at

67 and my bedroom at 60 or less...I have a modified window unit for that. The house is all-electric and very well insulated, my largest electric bills are
Reply to
Tom Gardner
Loading thread data ...

Reply to
Cross-Slide

Reply to
Karl Townsend

At 70F, your pressure should be a tad more than 10 lbs higher than that...and so either you have a bad thermometer or else the refrigerant is contaminated.

Thats a very real possibility.

Reply to
PrecisionmachinisT

It sounds like the Compressor needs a capacitor also.

Indeed, sometimes they use a common capacitor for fan and compressor.(three terminals- one common-one compressor-one fan) If you have an old analog ohm meter.........connect to common to one of the other terminals. The ohm meter needle should reduce ohms slowly. Reverse the leads of the meter on the same two terminals should repeat, then try the other two terminals. This not 100% test but will give you some idea if the capacitor has any capability. If you have a meter with capacitance test .......that would be even better. Hopefully the nephew will have some capacitors on the truck. Replacing the capacitor is the only true test. I have seem some test good and not start a compressor. Put a new one on and it ran like a charm. Good luck Lyndell

Reply to
Lyndell Thompson

finally it was good

condenser wouldn't start

seem OK so I

while then goes quiet

both sides at 70

this point I call in

heat baby and like the

that. The house is

Try a hard start kit.....Paul

formatting link

Reply to
Packratpaul

Reply to
Tom Gardner

I had to buy a new AC unit for the old house four years ago and one of my employees was an HVAC contractor. And, I sell brushes to "Famous Supply", a supply house. The whole ball of wax cost me $1k and my guy did it on the clock. Too bad he's in Texas now and won't be back in OH for two months...I can't wait that long. I imagine the worst so anything else will be a wonderful surprise!

Reply to
Tom Gardner

Well ... on my Carrier unit the starting capacitor for the compressor and the fan share the same housing, and in my case, the common wire opened, so the fan would start (the compressor provided the path to ground with the two capacitors in series), but the capacitance with power applied to the compressor was not sufficient to start it, so it sat there drawing excess current for while until it overheated, and then shut off until it cooled down enough for another try. Sounds a lot like what you have.

So -- replace the capacitor. IIRC, the fan was about 5 uFd, and the compressor about 55 uFd or something similar.

There is no real reason for the two capacitors to be in the same housing -- other than convenience in mounting. It was replaced with a single can which had six capacitors in it -- one of the smallest for the fan, and all the others in parallel for the compressor.

Once those were replaced, the system ran well again.

Why not? Proably $15.00 to $50.00 for the capacitor, and nothing else likely to be bad? I *think* that the pressures sound reasonable for a non running compressor. You will have a better feel for that when the compressor is running.

Did you even try to add any R-22? Proably not necessary.

Reply to
DoN. Nichols

Thanks Don, I feel a bit better now after reading about the caps! I sure hope that's it.

Reply to
Tom Gardner

On 5/1/2011 3:52 AM, Tom Gardner wrote: I feel a bit better now after reading about the caps! I

If the caps are ok also try whacking the compressor with a rubber mallet, after sitting unused all winter sometimes they need to be shook loose.

MikeB

Reply to
BQ340

Your static pressure is dependant upon temperature--it can be almost empty but as long as there is still a tiny amount of liquid remaining, the pressure will not drop.

If it is low, then in heat mode the outdoor unit will probably ice up rather quickly even under a fairly low humidity condition.....or it will trip the low pressure safety switch provided there is one installed.

There is probably a charging chart glued to the inside of one of the condensor access panels.

Reply to
PrecisionmachinisT

I'm on the lake about 25 miles west of Cleveland.

Reply to
Tom Gardner

Always remember your floaties, kid.

-- We're all here because we're not all there.

Reply to
Larry Jaques

I had heard Lake Erie is a great walleye fishery. True? Or did it just used to be?

Karl

Reply to
Karl Townsend

Probably the best in the world! And, big Smallies are plentiful and fight like demons. Some years are better than others depending on the spawn 3 and 4 years past. Yellow Perch are the best eating followed closely by Walleye. A guy that used to work for me has a charter service so I fish often. I too took the captain's test and had a six-pack license but I let it expire.

Reply to
Tom Gardner

Time to move into this century:

$39.99

A simple ESR meter is handy, too. It will show you if the capacitor can actually pass the required current.

You can build a simple one for under a buck:

formatting link

Reply to
Michael A. Terrell
[ ... my stuff snipped to save space ... ]

I'll bet that it is.

And beware of open commons inside the cap body. I didn't disconnect everything, so I wound up reading capacitance back through the compressor motor, so I mis-judged it.

The cap should have looked like this:

0-----------|(---------+----------)|-------------0 | | | ---

But really was like this:

0-----------|(---------+----------)|-------------0 | | --- -

Note the broken wire to the common ground.

Good Luck, DoN.

Reply to
DoN. Nichols

I think that he said that it was a heat pump, so it was probably running through the winter, too.

Enjoy, DoN.

Reply to
DoN. Nichols

I prize my VTVM, it has class even if it is a dinosaur. I also have a bunch of DVMs, some as cheap as $5 each, some as much as $150. It all depends on which is closest.

This cap has a feature, a "Physical interrupter for safety". Have you ever heard of that?

Reply to
Tom Gardner

PolyTech Forum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.