Additional Refrigerant Charge
Follow the procedures below.
Electric shock warning
1. Calculate how much refrigerant to be added.
2. Valve A and the stop valves must be left closed, charge the required amount of refrigerant
If the total refrigerant cannot be charged while the outdoor unit is at standstill, it is possible to
charge the refrigerant by operating the outdoor unit using the refrigerant charge function (refer
to "Setting mode 2" on page 76).
When charging a system, charging over the permissible quantity can cause liquid hammer.
Always use protective gloves and protect your eyes when charging refrigerant.
When the refrigerant charging procedure is done or when pausing, close the valve of the
refrigerant tank immediately. If the tank is left with the valve open, the amount of refrigerant
which is properly charged may get off point. More refrigerant may be charged by any
remaining pressure after the unit has stopped.
Close the electric box lid before turning on the main power.
Perform the settings on the circuit board (A1P) of the outdoor unit and check the LED display
after the power is on via the service lid which is in the lid of the electric box.
Operate switches with an insulated stick (such as a ball-point pen) to avoid
touching the life parts.
Make sure to re-attach the inspection cover into the switch box cover after
the job is finished.
If the power of some units is turned off, the charging procedure can not be finished properly.
Make sure to turn ON the power 6 hours before starting the operation. This is necessary to
warm the crankcase by the electric heater.
If operation is performed within 12 minutes after the indoor and outdoor units are turned on,
the H2P-LED will be lit and the compressor will not operate.
See "188.8.131.52 Stop Valve Operation Procedure" on page 70 for details on how to handle stop
The refrigerant charging port is connected to the piping inside the unit.
The unit's internal piping is already factory charged with refrigerant, so be careful when
connecting the charge hose.
After adding the refrigerant, do not forget to close the lid of the refrigerant charging port.
The tightening torque for the lid is 11.5 to 13.9 N·m.
In order to ensure uniform refrigerant distribution, it may take the compressor ±10 minutes to
start up after the unit has started operation. This is not a malfunction.
Charge with the outdoor unit at standstill
through the liquid side stop valve service port.
When the required amount of refrigerant is fully charged.
Record the amount of refrigerant that was added on the additional refrigerant charge
label provided with the unit and attach it on the back side of the front panel. Perform the
test procedure as described in "Test operation" on page 77.