Controls - Carrier 42N S-Serie Installations- Und Bedienanweisungen

Controls

Type "A" and "B" control (See fig. 30-31)
Type "A" control is used in 2-pipe systems.
Type "B" control is used in 4-pipe systems and 2-pipe systems with
electric heater.
Functions
(type "A" and "B" controls)
Type "A" and "B" controls have a knob to select the temperature, with
a range from 10°C to 30°C, and room temperature is maintained at the
selected value.
Fan operation
With the fan speed selector a, fan mode can be set either manually or
automatically.
In the manual mode it is possible to select three fan speeds (low/
medium/high) according to personal preference.
In the auto mode fan speed is regulated by a microprocessor in the
control in relation to the temperature chosen.
During installation, it is possible to select continuous fan operation via
the switch located on the electronic board (see paragraph "Dip-switch
configuration").
Unit extinction during heating mode is delayed by one minute to
allow for dispersion of residual heat present on the heat exchanger
coil or on the electric heater if installed (only for type "B" control).
As an option, fan operation can be disabled during heating, via a water
minimum temperature sensor (42N9004), if the water temperature is
below 40°C and during cooling if the water temperature is above 18°C.
These two functions allow improved comfort levels during winter and
energy saving during summer by turning the fan coils ON and OFF
automatically in relation to the water temperature.
Frost-protection
This function keeps the temperature from dropping below 7°C in rooms
not used for long periods of time.
When this temperature is reached and with the frost protection
function activated by a dip-switch (set during installation) located on
the electronic board (see paragraph Dip-switch configuration) the
control activates the valve(s) and puts the fan on high speed. The frost
protection function, if enabled, is activated even when the control is in
the OFF position.
Energy saving
This function is especially useful when air conditioning at night or in
rooms where the user is likely to be absent for a longer period of time.
In this case, pushing button raises the temperature during cooling by
4°C and lowers it during heating by 4°C.
Enabling this function (yellow LED ON) cuts out other displays.
Seasonal changeover
Manual
Selection of heating/cooling is done manually by pushing the button on
the control.
Centralised (only for type "A" control)
Centralised seasonal changeover can be done in two ways:
- by a switch located on the central control panel that allows heating/
cooling mode changeover (to be made by the installer).
- by a temperature sensor located in contact with the entering water
pipe (accessory).
In this last mode, fan coil operation is driven by the control, in cooling or
heating, depending on the temperature read by the sensor.
Switch and sensor operate on 230V power supply, so both must be
20 42N_S 42N_E
adequately insulated. If the seasonal manual changeover button
is pushed while the centralised changeover mode is activated, the
corresponding LED will briefly flash while maintaining the activated
mode. In any case, centralised changeover takes priority over local
changeover.
Automatic, based on air temperature (only for type "B" control)
The automatic seasonal changeover allows automatic switching of
the fan coil operating mode to cooling or heating, depending on the
temperature set by the user and on the room temperature.
External contact
The control has a 230V input that can be used as window contact or
presence detection. When such a signal is activated (presence of line
voltage on the terminal block contact) the control is set to OFF mode.
As a consequence, all outputs (fan, valves etc.) are disconnected, and
only the frost protection is active, if switched ON by the appropriate
dip-switch.
The external contact input (Ec) is directly connected to the mains
voltage (230V).
All connections must be properly insulated in order to prevent electric
shock.
Unit-mounted control
Preliminary operations:
Disconnect the main power supply.
Remove cabinet.
Access upper part of control box panel positioning the control as
shown.
IMPORTANT:
If necessary make dip switch configuration before closing the
control cover.
(See fig.32)
Open the control box p anel, carry out connections from the control
to the terminal block. The cable from the control has one or two
polarized connectors to avoid risk of connection errors.
Place the temperature sensor in the proper location.
Place the control in the proper metal plate tabs and fix it with the 2
screws.
Wall-mounted control
Prepare electrical connections between the control terminal block and
the unit control box panel.
Remove the control cover, unscrewing the screw located in the
bottom part.
Configure jumper (JP1) to the "activated internal sensor" position (see
paragraph "Use of temperature sensor").
Secure the control to the wall, marking the drill holes.
Drill the holes previously marked. Avoid drilling with the control
already placed on wall.
Fix the control using the screw anchors (See fig. 33)
IMPORTANT:
All connections between the unit and the control should be under
chase.
Handle the control with extreme care. Do not touch electronic
components to avoid damaging them.
Replace the control cover and the screw previously removed.