Drain Piping; Drain Discharging Boss - Hitachi RAS-3HVRNS3 Installation And Operation Manual

15

Drain piping

14.7 REFRIGERANT PUMP DOWN
When the refrigerant should be collected into the outdoor unit due
to indoor/outdoor unit relocation, collect the refrigerant as follows:
1 Attach the manifold gauge to the gas stop valve and the liquid
stop valve
2 Turn ON the power source
3 Set the DSW1-1 pin of the outdoor unit PCB at the "ON" side
for cooling operation. Close the liquid stop valve and collect
the refrigerant.
4 When the pressure at lower pressure side (gas stop valve)
indicates -0.01 MPa (-100 mmHg), perform the following pro-
cedures immediately.
- Close the gas stop valve.
14.8 CAUTION ON REFRIGERANT LEAKAGE
Specifiers/installers have responsibility to follow local codes and
regulation which specify safety requirements against refrigerant
leakage.
14.8.1 Maximum permissible concentration of HCFC/
HFC gas
The refrigerant R410A, charged in the system, is an incombusti-
ble and non-toxic gas. However, if leakage occurs and gas fills a
room, it may cause suffocation.
The maximum permissible concentration of HCFC/HFC gas,
R410A in air is 0.44 kg/m³, according to EN378-1.
Therefore, some effective measure must be taken to lower the
R410A concentration in air below 0.44 kg/m³, in case of leakage.
14.8.2 Calculation of refrigerant concentration
1 Calculate the total quantity of refrigerant R (kg) charged in
the system connecting all the indoor units of rooms to be air-
conditioned.
15 DRAIN PIPING

15.1 DRAIN DISCHARGING BOSS

When the base of the outdoor unit is temporarily utilized as a dra-
in receiver and the drain water in it is discharged, this drain boss
is utilized to connect the drain piping.
Model
DBS-12L
Connecting procedure

1 Insert the plastic cap into the drain boss up to the extruded
portions.
2 Insert the boss into the unit base up to the extruded portions.
3 Size of the drain boss is 15 mm (O.D.)
4 A drain pipe should be field-supplied.
19 PMML0318A - P5415337
Applicable Model
RAS-(2/2.5)HVNP1
RAS-3HVNC1
RAS-3HVRNS3
Set the DSW1-1 pin at the "OFF" side (To stop the unit
-
operation).
5 Turn OFF the power source.
C A U T I O N
Measure the low pressure by the pressure gauge and keep it not
to decrease than -0.01 MPa. If the pressure is lower than -0.01
MPa, the compressor may be faulty.
2 Calculate the room Volume V (m³) of each room.
3 Calculate the refrigerant concentration C (kg/m³) of the room
according to the following equation:
R R: Total quantity of charged refrigerant (kg)
≤ C V: Room volume (m³)
V C: Refrigerant concentration 0.44 kg/m³ for R410A
14.8.3 Countermeasure for refrigerant leakage
1 Provide a shutterless opening which allow fresh air to circula-
te into the room.
2 Provide a doorless opening of 0.15% or more size to the floor
area.
3 Pay a special attention to the place, such as a basement, etc.,
where refrigerant can stay, since refrigerant is heavier than
air.
N O T E
• Do not use this drain boss set in a cold area, because the
drain water may freeze.
• This drain boss is not sufficient 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 hole
Plastic cap
Plastic cap
Push Push
100 mm
≥ O.D. ∅ 16 mm
Drain hole
Plastic cap
Drain pipe