On Sun, 5 Oct 2014 13:56:12 -0400, "Flying Pig"
wrote:

Hi, Neal,

You'll really need to put gauges on both sides to see what's going on.

I spent MONTHS trying to sort out my Frigoboat; ultimately it failed, and I
had to replace it. The cause is known, but the stimulus is uncertain (I'm
one of only hundreds of similar experiences). The end result was the same.

However...

In the time I messed with it, I had wildly varying pressures. My issues
were a blockage which would sometimes move, or not.

Your gauges should have a temperature indication on them, and the suction
side should read colder the lower the pressure. FWIW, +15psi should be
about -8°F 134a temp. If you have a plate-mounted thermistor or equivalent
for on/off, you could compare temps of that point (where it mounts) to the
indicated temperature, with an IR heat sensor. It may not be exact (my and
my technician's didn't agree, even with fresh batteries in both, and neither
agreed with the thermistor's readout, nor the analog thermometer we hung in
there, e.g.) but it will give you an indication of whether your gauges are
correct. I'm assuming you've zeroed the gauge when not using it. I'm also
assuming you purge your gauge line before attaching it, whether by bleeding
or a can, the other way.

When you get the lockdown/restart, where is the frost on your suction side?
Right at the evaporator/cold plate-to-pipe? Somewhat inside it? Somewhere
down the tube? Do you have an expansion valve, capillary tube, or constant
pressure valve controlling your evaporation/boil/superheat point? Do you
have a receiver/drier and sight glass? If so, any bubbles in the sight
glass?

In my new system, there's a CPV, and a pretty good tolerance for over/under
charging as a result. YMMV of course.

Oh man, thanks for the help but you've made things WAY too complicated.

I'm not concerned with temperature readings on the gauge fittings. Who
cares? I'm perfectly happy when the evaporator is ice cold all around
so that it freezes cans of beer unless the thermostat is turned way
down. It does just that when the pressure in the suction side gauge
fitting is around 15psi when it's running. Neither am I concerned
with pressures on the compressed side. If the pressure on the
suction side is within specs then the pressure on the compressed
side will also be within specs. The only thing that could drive
up the pressure on the compressed side is if the tiny little
capillary in the evaporator should become clogged which it obviously
is not as the evaporator gurgles, hisses and chitters indicating
that compressed r134a is making its way through the capillary where
it then expands and freezes the heck out of my cans of beer which
fill the evaporator to the brim. (It's one of those vertical ones
an it holds about fifteen cans of beer which make a great drinkable
holding plate system)

All that other stuff you mentioned doesn't really apply as the Adler
Barbour doesn't have sight glasses, etc. It has a low pressure cut
off and a high pressure cut off and a high temp cut off and that's
about it. It's never gotten so hot that it cuts off because of that.

It does suffer from connection problems in the spade connectors to
the control panel, though. One must clean them and tighten them
by gentle crimping from time to time lest the resistance build to
the point where they fail to pass current.

It HAS and does cut off due to high pressure. Where the high pressure
in the suction side in the morning after it's sat idle all night comes
from is the question. Nobody seems to be able to answer that simple
question. Instead, everybody wants to go off on oddball tangents.

--
Sir Gregory