High-Pressure Switch And High-Pressure Sensor; High And Low-Pressure Side Safety Valves; Moisture Indicator; Filter Drier In The Refrigerant Circuit - Carrier 61WG 020 Installation, Operation And Maintenance Instructions

17.6 - High-pressure switch and high-pressure sensor

61WG/30WG 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 specific to the 61WG/30WG units - do
not interchange it with other units. The pressure switch tap
does not include a Schrader valve.
High-pressure switch
The high-pressure sensor is however equipped with a
Schrader valve. It is specific to these units and must not be
replaced with one from other Carrier units.
30WGA units are equipped with an automatically reset safety
pressure switch on the discharge line. The pressure switch is
specific for the 30WGA unit. Do not exchange it with other
units including the 61WG/30WG units.
High-pressure sensor
High-pressure switch
46
High-pressure sensor

17.7 - High and low-pressure side safety valves

The units are equipped with safety valves in accordance with
the European directive 97/23/CE. These safety valves are
calibrated and sized in accordance with the original high and
low-pressure side equipment.
Only 61WG/30WG units include high and low-pressure side
safety valves. 30WGA units are only equipped with a low-
pressure side safety valve. The installer must determine which
accessories (safety valves, fuses etc.) are required to ensure
that the completed high-pressure circuit complies with the
applicable regulations and standards.

17.8 - 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 insufficient 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.

17.9 - Filter drier in the refrigerant circuit

The filter keeps the circuit clean and moisture-free. The
moisture indicator shows when it is necessary to change the
filter cartridges. A temperature difference between the filter
drier inlet and outlet indicates a contamination of the
cartridges.
30WGA are equipped as standard with a filter 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 air-
cooled condenser.
Filter drier position