Dear Tony, got to disagree with you.

The headmaster control (switches on and off condensor fan) does stop
refrigerant from floading (try spelling it "flooding") the compressor.
Since the headmaster control keeps the refrigerant to the evaporator fairly
warm, the refrigerant can then turn to vapor. This provides for good
cooling, and reduces the odds of evaporator freezing.

Yes, headmaster switch does help compressor from cutting out on low pressure
switch. Has very little to do with pumping oil out of crankcase.

Crankcase heater is good in the winter. suction accumulator, can reduce
risk of oil slugging the compressor. I don't think that "large Recivers also
need rap around heater", the receiver is typically in the air flow from the
condensor. As such, it stays plenty warm. Which music group would you get to
rap around the heater? Glad it's outdoors, most restaurants don't like rap
music. Unless they are in the city. I've had a couple cases where the hot
blast of air from the condensor was over heating the receiver, and I've
wrapped it in cardboard so the refrigerant would not pick up more heat.

--
Christopher A. Young
Learn more about Jesus
www.lds.org
..


"Old and Grunpy" t. wrote in message
...

I do a lot of commercial HVAC and refrigeration
work and when I have to run a piece of equipment
under low ambient conditions like the AC at a
restaurant which often has to run in the winter,
I install whats called a "head pressure" or "low
ambient" control. For the large AC unit that you
would find at a restaurant, it's a simple matter
of controlling the condenser fan. When the fan
is turned off by the electric controller, the head
pressure rises until reaching a preset limit then
the condenser fan comes back on. This keeps things
from freezing up and protects the compressor from
flooding with liquid freon.

Sorry Uncle that does not stop refrigerant from floading compressor
but actually does the oposit however it helps for compressor from
cutting out on low pressure switch and saving compressor from
pumping oil out of crankcase. However for the health of compressor
if unit is going to be use all year round additional items need to be
install
(depend) on system size, Crankcase heater, suction accumulator,
large Recivers also need rap around heater.