61
18.6 - High-pressure switch and high-pressure
sensor
Units are equipped with an automatically reset safety pressure
switch on the liquid line. Refer to the controls manual for the alarm
acknowledgements.
It is strictly forbidden to modify the unit refrigerant circuit. The pressure
switch is specic to the units - do not interchange it with other units.
The pressure switch tap does not include a Schrader valve.
High-pressure switch
High-pressure sensor
The high-pressure sensor is however equipped with a Schrader
valve. It is specic to these units and must not be replaced with
one from other units.
30WGA units are equipped with an automatically reset safety
pressure switch on the discharge line. The pressure switch is
specic for the 30WGA unit. Do not exchange it with other units
including the 30WG units.
18.7 - High and low-pressure side relief valve
The units are equipped with relief valve in accordance with the
European directive 2014/68/UE. These relief valve are calibrated
and sized in accordance with the original high and low-pressure
side equipment.
Units include high and low-pressure side relief valve.
30WGA units are only equipped with a low pressure side relief valve.
The installer must determine which accessories (relief valves, fuses
etc.) are required to ensure that the completed high-pressure circuit
complies with the applicable regulations and standards.
18.8 - Moisture indicator
Located in the liquid line, permits control of the unit charge, as
well as the presence of moisture in the circuit. Bubbles in the sight
glass indicate an insufcient charge or the presence of non-
condensibles.
Regarding 30WGA units, if the indicator paper in the sight glass
is yellow during the delivery, it is not a non-conformity. It is
necessary to verify if the indicator paper in the sight glass is yellow
after the vaccum.
18.9 - Filter drier in the refrigerant circuit
The lter keeps the circuit clean and moisture-free. The moisture
indicator shows when it is necessary to change the lter cartridges.
A temperature difference between the lter drier inlet and outlet
indicates a contamination of the cartridges.
30WGA are equipped as standard with a lter drier that needs to
be soldered to the liquid line. It must be soldered as close as
possible to the 30WGA unit, upstream of the solenoid valve and
as soon as possible after the circuit has been exposed to the
atmosphere while connecting the aircooled condenser.
18.10 - Fixed-speed pump
This pump is factory-installed as standard to guarantee the nominal
ow in the water loop. It is a xed-speed pump with available system
pressure. See the pump ow/pressure curves in chapters 10 and 11.
The nominal system ow rate must be adjusted with a manual
control valve supplied by the customer (see chapters 10 and 11 on
the control of the nominal water ow rate).
The maximum permitted concentration of the glycol additives
(ethylene glycol or propylene glycol) is 35%.
The maximum pump suction pressure is limited to 400kPa (4Bar)
due to the valve installed on the entering water piping.
The use of any other glycol type additives must be approved by
manufacturer.
ATTENTION: Use of hydraulic module in an open loop is
forbidden.
18.11 - Variable-speed pump
This pump is factory-installed. It is a variable-speed pump with
available system pressure. See the pump ow/pressure curve.
The system ow rate is automatically adjusted via the frequency
converter built into the pump, based on the heat rejection load on
the drycooler.
The maximum permitted concentration of the glycol additives is 35%.
The maximum pump suction pressure is limited to 400kPa (4Bar)
due to the valve installed on the entering water piping.
The use of any other glycol type additives must be approved by
Manufacturer.
ATTENTION: Use of hydraulic module in an open loop is
forbidden.
18.12 - Evaporator and condenser pump
suction lter
Filter positions in the unit
All pumps are protected by a suction lter. This is easily removable
to recover solid particles. It protects the pump and the plate heat
exchanger against solid particles with a size exceeding 1,2 mm. Before
the unit start-up it is important to turn the evaporator and condenser
pump to decontaminate the water loops of any solid pollution.
A specic pump start-up function in the Quick Test menu is
available for this task.
18.13 - Outside air temperature (Option 312)
The Outside air temperature sensor is use to optimise set point
control with outside air temperature variation mesurement.
The position of the temperature sensor must be chosen with great
care and must be representative of the outside tempera-ture (limit any
other source that could have a negative inuence on the control: gusts
of wind, other heat sources such as sun radiation and hot air recycling).
The outside air temperature is also supplied with option 153, 154
(in drycooler) and 313.
18 - MAJOR SYSTEM COMPONENTS AND OPERATION DATA
To Next Page
Loading...
