Water Connections; Electrical Connections; Motorized Valve And Control - Carrier 42GW B Serie Manual De Instalación

Water connections

Water connections are fi xed to the unit body to avoid damage when
pipes are connected; it is advisable to tighten the connection with
a spanner. The upper coil connection is supplied with an air purge
valve, the lower connection with a water purge valve, suitable for a
10 mm wrench or screw-driver (See fi g. 26).
(The coil is only partially drainable; it it is advisable to blow air
into the coil for complete drainage).
Connections
Models
dimension (Ø)
004 3/4"
008 3/4"
010 3/4"
004* 1/2"
008* 1/2"
010* 1/2"
It is necessary, when the installation is made, to insulate the
valve and the connection pipes with anti-condensate material of
polyethylene type or expanded neoprene.

Electrical connections

STANDARD version unit - Control panel
(See fi g. 35)
The control panel can be reached by opening the grille and removing
the metal covers using the 3 or 4 screws (See fi g. 36).
Connect the power cables to terminal box connectors in accordance
with the wiring diagram and tighten fi rmly (See fi g. 38-39-40).
IMPORTANT: Make ground connection prior to any other electrical
connections.
• According to the installation instructions, all devices for
disconnection from the power supply mains must have a contact
opening (4 mm) to allow total disconnection according to the
conditions provided for the overvoltage class III.
• Fix the power supply cable under the corresponding cable holder.

Motorized valve and control

• The unit control circuit only allows opening of the motorized valve
when the fan motor is working.
• When the thermostat asks for cooling, outlet 1 of terminal TB3 on
the electronic board is powered at 230V (and the corresponding
chilled water valve is energized). When the thermostat asks for
heating, outlet 2 of terminal TB3 on the electronic board is powered
at 230V (and the corresponding hot water valve or electric heater is
energized).
• The control circuit ensures that the condensate discharge pump
works continuously while the thermostat, asking for cooling, keeps
the cold water regulating valve open.
WARNING : The valve is not only necessary to control the room
temperature, but also to stop the cold water fl ow to the coil in
case of an abnormal condensing water level rise in the drain pan.
Connections
Models
dimension (Ø)
012 1"
016 1"
020 1"
020* 3/4"
*Hot water circuits, four-pipe
version
Water temperature sensor
The unit has a temperature sensor installed on the inlet of the water
pipe whic is used to connect the condensate drain pump only when
water temperature drops below a value for which pump connection is
requested.
Checking
Before unit operation pour a quantity of water into the external
auxiliary drain pan (See fi g. 27). Verify that the water fl ows into the
internal condensate drain pan and that the pump regularly drains
the liquid. Otherwise check the pipe slope and look for possible
obstructions.
Water connections are fi xed to the unit body to avoid damage when
pipes are connected; it is advisable to tighten the connection with a
spanner.
Make certain that the YELLOW/GREEN cable is stripped back further
than the others (See fi g. 37-43).
• All the connecting cables to the fan coil unit and other accessories
should be of the H05VV-F type, with PVC insulation and in compliance
with the EN60335-2-40 standard.
Unit with electric heaters
To power the unit using the electric heaters, connect the power
supply cable not directly to the electronic board as in the versions
without heaters, but using the terminal as shown in fi g. 41-42.
IMPORTANT for units with electric heaters;
The unit is equipped with two thermostats: one with automatic reset
and one with manual reset that can be reactivated.
• If there is an abnormal condensing water rise in the drain pan (for
example: possible defective drain, pump malfunction, fan motor not
working) causing the opening of the fl oat switch contact (FS), the
control circuit either operates the condensate drain pump, or at the
same time closes the regulating valve, stopping the cold water fl ow
towards the coil and avoiding further condensation.
Control
The water fl ow has to be controlled:
• by installing the motorized thermo-electric valves supplied as
accessory
or
• by installing motorized fi eld supplied valves.
42 GW...B 25