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.

L8R

Skip

--

Morgan 461 #2
SV Flying Pig KI4MPC
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