About Refrigerants - Monaco Cayman 2005 Owner's Manual

Functional Test:
• Start and operate the engine
until the water reaches normal
operating temperature.
• Set the HVAC temperature
control to the full hot position.
• The discharge air outlets
should have hot air.
• Rotate the temperature control
to full cold position.
• Allow 10 minutes for the tem-
perature to stabilize.
• The discharge air outlets
should have cold air.
Vacuum Generator:
The vacuum generator creates vacuum to open and close the vacuum switches. The vacuum gen-
erator creates and stores 15" of vacuum in a reservoir ball. Output from the reservoir is sent to the vent
control knobs to open or close vents and switches. The vacuum generator will operate whenever the
ignition is ON, and the A/C is operating.
Chemical Stability:
The air conditioning system life and efficient operations depends upon the chemical stability of the
refrigeration system. The refrigeration system is made of Refrigerant-R134a and Polyakylene Gycol
(PAG) synthetic lubricant. It is very important that all materials contained within the refrigerant system
be chemically compatible.
NOTE:
An ultraviolet or UV Blue Light is used for leak detection.
The only suitable compound for use with R134a is PAG. The total amount of PAG within the
refrigerant system is approximately 18% of the total refrigerant in the system.
How much refrigerant is in the system? How much should be used when charging? You will
need 1 oz. of PAG for each 7 feet of hose after the first 15 feet of hose. Roughly, a 40 foot motorhome
will use 92 feet of refrigerant hose. Take 15 feet off the measurement and the result is 77 feet. This 77
feet is then divided by 7 for total of 11, and represents the number of ounces of PAG oil needed for the
A/C system (11 oz.).
Carrying the formula one step further, the 11 oz. equal approximately 18% of the entire system. The
total will equate to approximately 61 oz. or 3.8 lbs. of R134a.
Cayman 2005
090947
Vacuum Generator located in diesel
generator compartment.
Electrical Systems - Chassis --- Section 9
Vacuum Reservoir Ball located in
diesel generator compartment.

About Refrigerants

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