Installation manual17 ERHQ011~016BAV3+W1 + ERLQ011~016CAV3+W1Outdoor unit for air to water heat pump4PW57794-1C – 2013.0412.3. Calculating the additional refrigerant charge forERHQ modelsIt is not necessary to charge additionally if the piping length is under10 m.If the piping length is over 10 m please determine the additionalamount of refrigerant to be charged using the formula below.R=(total length (m) of liquid piping – 10 m) x 0.054R=additional charge (kg)(rounded in units of 0.1 kg)12.4. Calculating the additional refrigerant charge forERLQ modelsIt is not necessary to charge additionally if the piping length is under10 m.If the piping length is over 10 m please determine the additionalamount of refrigerant to be charged using the formula below.R=(total length (m) of liquid piping – 10 m) x 0.054R=additional charge (kg)(rounded in units of 0.1 kg)12.5. Complete rechargingIn case complete recharging is required (after a leak, etc.), refer tothe information below to determine the necessary amount ofrefrigerant.For ERHQ onlyFor V3 modelsTotal charging amount Charge of refrigerant (kg) depends on total liquid piping length.Total refrigerant charge = 2.7 kg + (total length (m) of liquid piping– 10 m) x 0.054Remark: Factory refrigerant charge is 2.7 kgFor W1 modelsTotal charging amount Charge of refrigerant (kg) depends on total liquid piping length.Total refrigerant charge = 2.95 kg + (total length (m) of liquid piping– 10 m) x 0.054Remark: Factory refrigerant charge is 2.95 kgFor ERLQ onlyTotal charging amount Charge of refrigerant (kg) depends on total liquid piping length.Total refrigerant charge = 3.4 kg + (total length (m) of liquid piping– 10 m) x 0.054Remark: Factory refrigerant charge is 3.4 kg13. PUMP DOWN OPERATIONThis unit is equipped with an automatic pump down operation whichwill collect all refrigerant from the field piping and indoor unit in theoutdoor unit. To protect the environment, make sure to perform thefollowing pump down operation when relocating or disposing of theunit.1 Turn on the main power supply switch.2 Make sure the liquid stop valve and the gas stop valve are open(see "9.3. Stop valve operation" on page 13).3 Press the pump down button (BS4) on the PCB of the outdoorunit for at least 8 seconds.4 The compressor and outdoor unit fan will start operatingautomatically.5 Once operation stops (after 3 to 5 minutes), close the liquid stopvalve and the gas stop valve.6 The pump down operation is now finished. The remote controllermay display "U4" and the indoor pump may continue operating.This is not a malfunction. Even when the ON button on theremote controller is pressed, the unit will not start to operate. Torestart operation of the unit turn off the main power supplyswitch and turn it on again.7 Turn off the main power supply switch.NOTICEPiping length is the one way length of liquid piping.NOTICEMinimum piping length = 3 m.NOTICEPiping length is the one way length of liquid piping.NOTICEBefore recharging, make sure to execute vacuum drying ofthe internal piping of the unit as well. To do so, use theinternal service port of the unit. Do NOT use the serviceports located on the stop valve (see "9.3. Stop valveoperation" on page 13), since vacuum drying can not beperformed properly from these ports.Outdoor units have 1 port on the piping. It is between theheat exchanger and the 4-way valve.NOTICEMinimum piping length = 3 m.INFORMATIONFor more details, refer to the applicable service manual.WARNINGThe outdoor unit is equipped with a low pressure switch ora low pressure sensor to protect the compressor byswitching it off. Never short-circuit the low pressure switchduring pump down operation!NOTICEBefore pumpdown is activated be sure that the watertemperature and water volume is sufficiently high.Pumpdown is done in "cooling mode". See installationmanual of the indoor unit for more details.WARNINGMake sure to re-open both stop valves before restartingoperation of the unit.
