Hitachi YUTAKI S Serie Manuel D'installation page 14


DANGER:
- Pressure Vessel and Safety Device: This air conditioner
is equipped with a high pressure vessel under PED
(Pressure Equipment Directive). The pressure vessel
has been designed and tested before shipment according
to PED. Also, in order to prevent the system from an
abnormal pressure, a high pressure switch, which needs
no field adjustment, is utilized in the refrigeration system.
Therefore, this air conditioner is protected from abnormal
pressures. However, if abnormally high pressure is
applied to the refrigeration cycle including the high
pressure vessel(s), it will result in serious injury or death
due to explosion of the pressure vessel. Do not apply a
pressure higher than the following pressure to the system,
by modifying or changing the high pressure switch.
- Maximum Allowable Pressure and High Pressure Cut-out Value:
Product Series
HRNME Series

NOTE:
The label for the vessel under PED are attached on the
high pressure vessel. The pressure vessel capacity and
vessel category are indicated on the vessel.
Location of High Pressure Switch
Compressor

DANGER:
Do not change the high-pressure switch locally or change the high pressure cut-out set value locally. If changed, it will cause
−
serious injury or death due to explosion.
Do not attempt to turn service valve rod beyond its stop
−
16
PMML0215A rev.1 - 02/2012
Outdoor Unit Model
RAS-8~10HRNME-AF
- Start-up and Operation: Check to ensure that all the
stop valves are fully opened and no obstacle exists at the
inlet/outlet sides before start-up and during the operation.
- Maintenance: Periodically check the high pressure side
pressure. If the pressure is higher than the maximum
allowable pressure, stop the system and clean the heat
exchanger or remove the cause.
Maximum Allowable
Refrigerant
Pressure (MPa)
R410A 4.15

NOTE:
The high pressure switch is indicated on the electrical
wiring diagram in the outdoor unit as "PSH" connected to
printed circuit board (PCB1) in the outdoor unit.
Structure of High Pressure Switch
Contact Point
Conected to the
electrical wire
IMPORTANT NOTICE
High Pressure Switch
Cut-out Value (MPa)
4.00 ~ 4.10
Pressure detected