On Sat, 04 Oct 2014 15:28:37 -0400, "Sir Gregory Hall, Esq."
wrote:

On Sat, 04 Oct 2014 07:34:51 +0700, wrote:

On Fri, 03 Oct 2014 10:38:12 -0400, "Sir Gregory Hall, Esq."
wrote:

On Fri, 03 Oct 2014 19:08:56 +0700, wrote:
On Thu, 02 Oct 2014 15:14:32 -0400, "Sir Gregory Hall, Esq."
wrote:

I can't figure it out. I keep having to let refrigerant out
of my Adler Barbour. It runs great with the suction-side
pressure set at 15 psi. But, every month or so it will
commence to cycle off and on after being off for the night.

I put a gauge on it and the suction side pressure is in the
beginning of the red range(55 psi). It turns on and the
compressor starts compressing, the pressure starts going
down but it only gets to about 45 psi until the compressor
*clicks off* and the voltage gauge goes up a volt or two
because the load comes off the circuit.

Then it turns itself off and back on and the compressor
starts to compress again and the pressure goes down to about
45 psi, then it cycles off again.

So, I let out some pressure until it only starts out around
45 psi and it will finally keep compressing until it draws
down the suction side to about 15 psi where it stabilizes.

So where does the extra pressure come from. I've had to
let out ten pounds of pressure about half a dozen times
this summer. I can understand leaks but this is ridiculous!

You have a closed system connected to a compressor. One side to the
suction side and the other to the pressure side. Think why the suction
side would be at a higher pressure, or conversely, why the low
pressure side is at a lower pressure in a properly operating system.

Since the two sides are able to equalize when the compressor
sits idle overnight the suction side and the compressed side
should be the same. So, when I measure the suction side at
startup and it shows 50 psi that means the compressed side
is also (temporarily) at 50. As the suction side pressure
decreases the compressed side increases.

So, if I measured pressure on the suction side in Jult after
it has sat idle all night it and it starts out being 30psi,
do tell why in August it will suddenly be reading 50psi on
the same suction side at start up?

As I said, it IS a closed system. If the system has been off for a
sufficient period the entire system should be the same pressure as the
refrigerant will be the same temperature throughout the system.

Then you start the system and the compressor sucks on one side and
blows on the other as it is a closed system why aren't the two sides
of the system still at the same pressure?

I fear you may suffer from reading comprehension problems, Bruce.

I understand what you just typed and the problem has nothing to
do with a system that's running and everything to do with a
system that has been turned off for the night.

In the morning, before starting, when the system is stabilized
so that suction side pressure equals compression side pressure
This is what I read on the suction side (i.e. it will be the
same on the compressed side).

July 38 psi
August 45 psi (so I let out five psi)
Sept. 60 psi (so I the let out 20 psi)

In other words, even though I let out pressure because
it gets so high that the compressor, when started for
the first time in the morning, cycles off and on because
of the high pressure cut-out circuit. That's why I have
to let out pressure so it will get about the business
of refrigerating.

So where does the excess pressure come from? And, don't
say water vapor as there will be no steam even if there
is water vapor when the system is cool and stabilized
in the morning.

I've been trying to get you to reason rather then just bitch and moan.
Think about why a totally closed system might have a significantly
different pressure for the suction and pressure sides of a compressor
when running and the same pressure on each side when the system is
shut down for a while.

You seem to be saying that your stabilized system pressure is high....
Have you checked the temperature of the system -- usually OAT and
looked at a temperature - pressure table to be sure that it isn't a
temperature problem?
--
Cheers,

Bruce in Bangkok

On Sun, 05 Oct 2014 10:47:40 +0700, wrote:

On Sat, 04 Oct 2014 15:28:37 -0400, "Sir Gregory Hall, Esq."
wrote:

On Sat, 04 Oct 2014 07:34:51 +0700, wrote:

On Fri, 03 Oct 2014 10:38:12 -0400, "Sir Gregory Hall, Esq."
wrote:


I've been trying to get you to reason rather then just bitch and moan.
Think about why a totally closed system might have a significantly
different pressure for the suction and pressure sides of a compressor
when running and the same pressure on each side when the system is
shut down for a while.

You seem to be saying that your stabilized system pressure is high....
Have you checked the temperature of the system -- usually OAT and
looked at a temperature - pressure table to be sure that it isn't a
temperature problem?

He's misreading the gauges, has bad gauges, or is wrong about the
system being in a stable state.

On Sun, 05 Oct 2014 07:12:58 -0500, Vic Smith
wrote:

On Sun, 05 Oct 2014 10:47:40 +0700, wrote:

On Sat, 04 Oct 2014 15:28:37 -0400, "Sir Gregory Hall, Esq."
wrote:

On Sat, 04 Oct 2014 07:34:51 +0700, wrote:

On Fri, 03 Oct 2014 10:38:12 -0400, "Sir Gregory Hall, Esq."
wrote:


I've been trying to get you to reason rather then just bitch and moan.
Think about why a totally closed system might have a significantly
different pressure for the suction and pressure sides of a compressor
when running and the same pressure on each side when the system is
shut down for a while.

You seem to be saying that your stabilized system pressure is high....
Have you checked the temperature of the system -- usually OAT and
looked at a temperature - pressure table to be sure that it isn't a
temperature problem?

He's misreading the gauges, has bad gauges, or is wrong about the
system being in a stable state.

You two are hopeless as you both can't seem to render things down
to the basics.

The basics are that the suction side and the compressed side will
carry the same psi after the system has sat all night long turned
off. It doesn't matter where one puts the gauge as the pressure
will be the same throughout. The compressor *leaks* and is not
some sort of impermeable membrane. Duh. And don't say there is
some kind of a check valve in the system as that would also be
silly as the evaporator is a free flow device.

Silly speculation as to the system being hot might be the problem
are just that - silly as the compressor will be at room temperature
in the morning. Actually it will be closer to water temperature as
it's installed in the bilge.

My question of where does the extra psi come from remains
unanswered.

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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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

On Sun, 05 Oct 2014 13:15:55 -0400, "Sir Gregory Hall, Esq."
wrote:

On Sun, 05 Oct 2014 07:12:58 -0500, Vic Smith
wrote:

On Sun, 05 Oct 2014 10:47:40 +0700, wrote:

On Sat, 04 Oct 2014 15:28:37 -0400, "Sir Gregory Hall, Esq."
wrote:

On Sat, 04 Oct 2014 07:34:51 +0700, wrote:

On Fri, 03 Oct 2014 10:38:12 -0400, "Sir Gregory Hall, Esq."
wrote:


I've been trying to get you to reason rather then just bitch and moan.
Think about why a totally closed system might have a significantly
different pressure for the suction and pressure sides of a compressor
when running and the same pressure on each side when the system is
shut down for a while.

You seem to be saying that your stabilized system pressure is high....
Have you checked the temperature of the system -- usually OAT and
looked at a temperature - pressure table to be sure that it isn't a
temperature problem?

He's misreading the gauges, has bad gauges, or is wrong about the
system being in a stable state.

You two are hopeless as you both can't seem to render things down
to the basics.

The basics are that the suction side and the compressed side will
carry the same psi after the system has sat all night long turned
off. It doesn't matter where one puts the gauge as the pressure
will be the same throughout. The compressor *leaks* and is not
some sort of impermeable membrane. Duh.

And don't say there is
some kind of a check valve in the system as that would also be
silly as the evaporator is a free flow device.

The evaporator is a free flow device? Well yes it is but there is a
valve or other restriction in there. Or is it just another thing that
you don't know?

Silly speculation as to the system being hot might be the problem
are just that - silly as the compressor will be at room temperature
in the morning. Actually it will be closer to water temperature as
it's installed in the bilge.

Well yes, silly. Except of course that with a gas pressure is
associated with temperature.

My question of where does the extra psi come from remains
unanswered.
--
Cheers,

Bruce in Bangkok

On Mon, 06 Oct 2014 07:02:15 +0700, wrote:

On Sun, 05 Oct 2014 13:15:55 -0400, "Sir Gregory Hall, Esq."
wrote:

On Sun, 05 Oct 2014 07:12:58 -0500, Vic Smith
wrote:

On Sun, 05 Oct 2014 10:47:40 +0700, wrote:

On Sat, 04 Oct 2014 15:28:37 -0400, "Sir Gregory Hall, Esq."
wrote:

On Sat, 04 Oct 2014 07:34:51 +0700, wrote:

On Fri, 03 Oct 2014 10:38:12 -0400, "Sir Gregory Hall, Esq."
wrote:


I've been trying to get you to reason rather then just bitch and moan.
Think about why a totally closed system might have a significantly
different pressure for the suction and pressure sides of a compressor
when running and the same pressure on each side when the system is
shut down for a while.

You seem to be saying that your stabilized system pressure is high....
Have you checked the temperature of the system -- usually OAT and
looked at a temperature - pressure table to be sure that it isn't a
temperature problem?

He's misreading the gauges, has bad gauges, or is wrong about the
system being in a stable state.

You two are hopeless as you both can't seem to render things down
to the basics.

The basics are that the suction side and the compressed side will
carry the same psi after the system has sat all night long turned
off. It doesn't matter where one puts the gauge as the pressure
will be the same throughout. The compressor *leaks* and is not
some sort of impermeable membrane. Duh.

And don't say there is
some kind of a check valve in the system as that would also be
silly as the evaporator is a free flow device.

The evaporator is a free flow device? Well yes it is but there is a
valve or other restriction in there. Or is it just another thing that
you don't know?

Silly speculation as to the system being hot might be the problem
are just that - silly as the compressor will be at room temperature
in the morning. Actually it will be closer to water temperature as
it's installed in the bilge.

Well yes, silly. Except of course that with a gas pressure is
associated with temperature.

My question of where does the extra psi come from remains
unanswered.

===

Someone suggested contamination and I think that is the right track,
especially in view of the fact that you didn't use a vacuum pump on
the system after fixing a leak. All of the professionals that I know
will *always* use a vacuum pump after repairing a leak. They are not
that expensive and a good investment if you are doing you're own work.
If you also get a leak detector, a full gage set and an IR temp gun,
you can not only fix your own system, but also hire out and make some
cash on the side.