Daikin McQuay AGZ-D Operating And Maintenance Manual page 76

Special tools will be required due to higher
refrigerant pressures with R-410A. Oil-less/hp
recovery units, hp recovery cylinders (DOT
approved w/525# relief), gauge manifold 30"-
250 psi low/0-800 psi high, hoses w/800 psi
working & 4,000 psi burst.
All filter driers and replacement components
must be rated POE oils and for the refrigerant
pressure (R-410A 600psig typical).
R-410A compressor internal relief is 600-650
psid.
Brazed connections only. No StayBrite or
solder connections (solder should never be
used with any refrigerant). K or L type
Service on this equipment is to be performed by qualified refrigeration personnel
familiar with equipment operation, maintenance, correct servicing procedures, and the
safety hazards inherent in this work. Causes for repeated tripping of equipment
protection controls must be investigated and corrected.
Disconnect all power before doing any service inside the unit.
Anyone servicing this equipment must comply with the requirements set forth by the
EPA in regards to refrigerant reclamation and venting.
Filter-Driers
A replacement of the filter-drier is
recommended any time excessive pressure
drop is read across the filter-drier and/or when
bubbles occur in the sight glass with normal
subcooling. The maximum recommended
pressure drops across the filter-drier are Table
22
The filter-drier should also be changed if the
moisture indicating liquid line sight glass
indicates excess moisture in the system.
76
WARNING
!
Table 22, Filter-Drier Pressure Drop
PERCENT CIRCUIT MAXIMUM RECOMMENDED PRESSURE
LOADING (%) DROP ACROSS FILTER DRIER PSIG (KPA)
100%
75%
50%
25%
AGZ 025D through 190D
refrigeration tubing only. Use nitrogen purge.
Higher R-410A pressures and smaller molecule
size make workmanship more critical.
R-410A must be charged from cylinder as a
liquid unless entire cylinder is used. Use a
Refrigerant flow restrictor if charging liquid to
suction or to a system at pressure below a
saturated temperature of 32° F.
EPA recovery and handling requirements for R-
410A are the same as R-22.
Cooling the recovery cylinder will speed
recovery and lessen stress on recovery
equipment.
During the first few months of operation the
filter-drier replacement can be necessary if the
pressure drop across the filter-drier exceeds the
values listed in the paragraph above. Any
residual particles from the condenser tubing,
compressor and miscellaneous components are
swept by the refrigerant into the liquid line and
are caught by the filter-drier.
10 (69)
8 (55.2)
5 (34.5)
4 (27.6)
OMM 1087