
139
Charging Multiplex Remote Refrigeration Unit
NOTE: System would have been opened for repairs.
Once completed, a vacuum of 500 microns would
have been maintained for 1/2 hour. The proper
procedure for charging the system includes the
reintroduction of all refrigerant that had been
recovered before making the repair.
1. Attach charging hose of gauge manifold to liquid
valve of the recovery cylinder (if no refrigerant
was in the system, and thus, no refrigerant was
recovered, attach charging hose to Refrigerant
cylinder). Open cylinder valve.
2. Place cylinder on charging scale-zero scale.
3. Open high side valve wheel of gauge manifold.
DO NOT ATTEMPT TO CHARGE SYSTEM ON
LOW SIDE—CHARGE IN A LIQUID STATE
ONLY WITH REFRIGERATION SYSTEM OFF.
4. Allow sufficient time for all refrigerant to transfer
from cylinder to refrigeration unit. If necessary, put
cylinder into bucket of hot water to increase the
internal pressure of the cylinder.
5. System total charge is the net result of:
A. Refrigeration Unit charge on nameplate
B. Remote line set length X .72 oz./ft.
C. 90% of condenser volume (cu. ft.) x
Refrigerant (wt./cu ft)
NOTE: Refrigerant weight varies with temperature.
R-404A weighs 72 lb/cu. ft. @ 32°; 62 lb/cu. ft. @ 95°
6. When all refrigerant has been transferred, close
valve wheel of the manifold.
7. Turn refrigeration unit on.
STH13_Tech.book Page 139 Wednesday, September 15, 2010 3:20 PM