Cycling A/C compressor Part II

["content22207" <brobertson@xxxx>]

Just drove 7 hours on I-95. Only time compressor cycled was when I
manually shut off for added power (hills before Richmond). All points
south it just pumped and pumped as happy as could be (R134 thank you
very much).

Regarding your other post: cut off switch is a LOW pressure switch. If
system becomes clogged with ice, high side pressure DROPS. Hence the
cycled compressor. Only way to get high side into hundreds of PSI is
with refrigeration cycle.

You've also got cart a little before the horse. Freon boils just fine
without any outside help. Compressor changes gas to liquid, not other
way around.

Purpose of compressor is to raise pressure in condensor high enough
for freon to re-liquify (it's pumping the same gas that just left the
evaporator). On a Lincoln covers distance less than two feet. 200 PSI
starts AFTER condensor. That's why those lines made of metal, not
hose. Local A/C mechanic claims latent energy in freon trying to boil,
but slowed by orifice, creates pressure.

Re: high compressor pressure blowing system apart (bad news there is
compressor output really isn't all that strong) -- my car has no HIGH
pressure switch, only a low one. If I'm reading archives correctly, am
not alone. High pressure switch appears to be late VIN addition, not
part of original design.

BTW: Does anybody know rating of low pressure switch? Translates into
25+ PSI on low side burning R134 (clear system).

Bill Robertson
#5939

>--- In dmcnews@xxxxxxxxxxxxxxx, "Harold McElraft" <hmcelraft@xxxx> wrote:
> NOT SO! I'm sure you did not hear their comments completely. It is 
> called a CCOTT system because it stands for Clutch Cycling Orifice 
> Tube Type system. Note the word cycling. Also, if you read the 
> second paragraph on page N:01:01 it explains how the system 
> operates. I'm sure the intent of their statements were - on a hot 
> day the clutch may rarely cycle - which I would say it correct.
> 
> Harold McElraft - 3354
> 
> 
> -- In dmcnews@xxxxxxxxxxxxxxx, id <ionicdesign@xxxx> wrote:
> > I just got my A/C recharged by a place that just works on cooling 
> systems and they said
> > the compressor will only cycle if it is low on freon, DMCH also 
> agreed. The compressor
> > should never cycle.
> > 
> > Mark