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5. Recovering Refrigerant
Refrigerant in all indoor units and the refrigerant tubing circuit must be pumped into the outdoor unit. The maximum refrigerant storage capacity per a single outdoor unit is approx. 529 oz. Thus, in order to collect all refrigerant from the system, a separate refrigerant recovery unit is necessary. Follow these procedures to correctly perform pump down.
Perform work correctly, according to the work procedures given below.
1Connect the manifold gauge to the high- and
2Follow the instructions in
3When the
2below, at the outdoor unit where pump down is being performed, press the ON/OFF button on the outdoor unit maintenance remote controller to stop operation at all units. Then immediately fully close the suction tube valve on the outdoor unit where pump down is being performed.
* If the outdoor unit maintenance remote controller is unavailable, follow the procedure below to stop all of the units.
Pull out the SCT connector (2P) (YEL) (CN231) on the outdoor unit control PCB of the unit where pump down is being performed. When the SCT connector is pulled out, immediately alarm F12 (sensor trouble) occurs and all outdoor units stop operating. Be sure that you do NOT grasp the lead wire when pulling out the con- nector. Removing any other connector may not cause the units to stop. Therefore be sure to pull out the SCT connector only.
CAUTION
It is not necessary to recover the refrigerant from the balance tube. Therefore do not operate the balance tube valve.
4Turn off power to all equipment in the system. Then pull out the RC1 connector (4P) (BLU) (CN106) on the out- door control PCB in the outdoor unit for which pump down has been completed.
* By pulling out the RC1 connector, communication between the main and the sub outdoor units will be isolated.
5Change the setting of controllable outdoor unit numbers (reduce by 1 unit).
* If the setting is incorrect, the E30 alarm (outdoor unit serial communication signal error) occurs and the unit will not operate.
6Turn on power for all equipment in the system and let the remaining outdoor units run in Cooling mode.
7 Repeat steps 1 and 2 and complete pump down for all outdoor units.
8Using hoses with
CAUTION
Remaining refrigerant in the system may cause internal pressure. Check that each valve on the manifold gauge is tightly closed. A
9Use hoses to connect the manifold gauge valves, refrigerant recovery unit, and refrigerant recovery cylinder. Quickly connect each part to prevent air from entering the tubing.
10Recover remaining refrigerant from the
NOTE
To determine the completion of refrigerant recovery, follow the instructions that came with the refrigerant recovery unit.
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