"DoN. Nichols" wrote in message
...
On 2011-04-30, Tom Gardner w@w wrote:
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.

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.

So, I assume the worst on this 15 yo Trane and it won't be worth
fixing.

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.

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 $200/mo for everything so I don't expect to see
huge savings with a new heat pump.

If he knows what he is doing, he can probably come up with a
replacement capacitor for you.

I'm happy when this room is 80 F or below (lots of computers
running here) and the bedroom is around 75 F.

Good Luck,
DoN.

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