Service - Daikin McQuay AGZ-D Operating And Maintenance Manual

Service

R-410A
Refrigerant Terminology
Bubble Point: The temperature/pressure where
bubbles first appear when heat is added to a
liquid refrigerant. Used to measure sub-
cooling.
Dew Point: The temperature/pressure where
droplets first appear when heat is removed
from a refrigerant gas. Used to measure
superheat.
Fractionalization: A change in refrigerant
composition due to the tendency of the higher
pressure refrigerant to leak at a faster rate,
should a system have leakage from a static
two-phase region.
Glide: The total difference of Dew and Bubble
Point at a specific condition. Mid-Point or
Mean: Measurement half way between Dew
and Bubble Points.
Miscibility: The ability of a refrigerant and oil
to mix and flow together.
Solubility: The effect of refrigerant on the
viscosity of a lubricant.
Safety
Comparable to R-22; ANSI/ASHRAE safety
group A1.
Always carry and be familiar with MSDS
information for R-410a.
Store refrigerant in clean, dry area out of direct
sunlight.
Never heat or store cylinders above 125° F.
Note vehicle precautions!
Never tamper with cylinder valves or pressure
relief valves. (Typical relief for R-410A is 525
psig).
Never refill disposable cylinders.
Verify cylinder hook-up.
Verify cylinder label and color code match. R-
410A is rose/light maroon. Must be DOT
approved, R-410A with 400 psig rating. Open
cylinders slowly.
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Avoid rough handling of cylinders and secure
as appropriate. Cap when not in use.
Do not overfill recovery cylinders or
overcharge units.
Check gauge calibration before every use and
manifold set for leaks regularly.
Be aware of pneumatic and possible
hydrostatic pressure potentials.
Never pressurize systems with oxygen or
ref/air mix. R-410A, R-407C, R-134A, & R-22
are flammable with low air mix.
Wear protective clothing. Impervious gloves
and splash goggles should be worn.
Avoid contact with liquid refrigerant (R-410A -
60.8°F @ atms.) due to corrosion and freezing
hazards.
Avoid exposure to vapors. 1000 ppm/8 hr.
Evacuate areas in cases of large releases. R-
410A is heavier than air and can cause
asphyxiation, narcotic and cardiac sensation
effects.
Evacuate systems and break vacuum (0 psig)
with nitrogen before welding or brazing.
Always ventilate work areas before using open
flames. Exposure to open flames or glowing
metal will form toxic hydrofluoric acid &
carbonyl fluoride. No smoking!
Make sure all tools, equipment, and
replacement components are rated for the
refrigerant used.
Lubrication
POE oil is extremely hydroscopic, is polar in
nature (picks up dirt, etc.), and will hydrolyze
(produce acids) in the presence of water.
Use only the manufacturer's recommended oil.
Use only new sealed metal containers of oil to
insure quality.
Buy smaller containers to prevent waste and
contamination.
AGZ 025D through 190D OMM 1087