Hitachi UTOPIA R410A Series - 8.6 REFRIGERANT CHARGING QUANTITY

8.6 REFRIGERANT CHARGING QUANTITY
Outdoor Units has been charged with refrigerant for 20m of
actual piping length (L). An additional refrigerant charge is
required in systems with actual piping length longer than 20m.
1 Determine an additional refrigerant quantity according to the
following procedure, and charge it into the system.
2 Record the additional refrigerant quantity to facilitate service
activities thereafter.
Outdoor unit
Refrigerant
charge before
shipment
(W
0
(kg))
Additional
refrigerant
charge
(g/m)(P)
Maximum
additional
charge
(kg)

3.0 45 2.9






3.2 60 3.9





! CAUTION
• Whenchargingrefrigerant,measuretheamountprecisely.
• Overloadingor underloading of refrigerant may cause compressor
problems.
• Iftheactualpipinglengthislessthan5mconsultyourdealer.
• Ifambienttemperature>43ºC,minimumactualpipinglengthis15m.
• Charge refrigerant correctly. Overcharging or insufcient charging
couldcauseacompressorfailure.
Additional refrigerant charge calculation method
Use the following formula: W
1
= (L-20) x P
Setting of Pipe Length DSW
DSW2 setting will be required only when the refrigerant pipe
length is shorter than 5 m or longer than 30 m. Pipe length
setting shall be performed as shown below.
(The  side in the table below shows the DSW location)
DSW2 on outdoor PCB1
Factory setting  
9 DRAIN PIPING
9.1 DRAIN DISCHARGING BOSS
When the base of the outdoor unit is temporarily utilized as a
drain receiver and the drain water in it is discharged, this drain
boss is utilized to connect the drain piping.
Model Applicable Model
DBS-26 All units
Drain hole (connexion for DBS-26)
Drain hole (*)
(*) To cover these drain holes, sealing pads are included
in DBS-26 kit.
Connecting procedure for DBS-26
Rubber
cap
Drain hole
(DBS-26)
Drain pipe
Extruted
portions
Drain boss
1 Insert the rubber cap into the drain
boss up to the extruded portions.
2 Insert the boss into the unit base
and turn approximately 40 degree
counterclockwise.
3 Drain boss is 32 mm (O.D.).
4 
? NOTE
• Donot use thisdrain bossset in acold area,because thedrain
watermayfreeze.Thisdrainbossisnotsufcienttocollectallthe
drainwater.Ifcollectingdrainwateriscompletelyrequired,provide
adrain-panthatisbiggerthantheunitbaseandinstallitunderthe
unitwithdrainage.
Drain piping
PMML0545 rev.2 - 04/2021
12
EN