Acson international ADB100D, Manual

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24
Most split systems have a suitable connection on the outdoor unit
Shredder valves provide easy system access for pressure reading and addition of refrigerant. On small sys-
tems, they provide a reasonable connection for evacuation also. However, Shredder valves and the hoses
connected to them can cause very severe pressure drops and can multiply evacuation time by a factor of 4 or 5.
On the positive side, Shredder valves provide a restriction that slows the speed of liquid charging into the suction
side. When a pressure drop is desirable (charging liquid into suction), connect via a Shredder valve. When a
pressure drop is detrimental (evacuation), connect via an open fitting.
HOW MUCH REFRIGERANT?
The proper refrigerant charge should follow the volume as recommended by manufacturer and recommenda-
tion should be followed by the installer. Refer to the table of Refrigerant Charge Level.
If the installer cannot find the correct charge but the system must be started, refrigerant should be carefully
added to the system until reasonable sub-cooling is measured in the liquid line and reasonable suction super-
heat is measured at the compressor suction. Suction and discharge pressures must be monitored carefully
during the charging process.
CHARGE LIMITS
Copeland Scroll compressors have the different charge limits for different compressor models as shown in table
below. If the total charge exceeds these limits, the system should have a crankcase heater and/or pump down
cycle and/or accumulator to prevent liquid damage to the compressor. Some systems may require accumula-
tors to limit liquid floodback even though the charge is lower than the published limit.
Compressor Range Model lbs. kg.
Quest ZR46 to ZR81 10 4.5
Summit ZR84 to ZR144 16 7.3
Specter ZR90 to ZR19M 17 7.7
Typical service valves
found on the outdoor unit
Shredder valve with
core in place Shredder valve with core removed
Shredder valves
Shredder core