Flexible Pipe Option; Optional Electric Heater; Optional Water Sensor; Optional Condensate Pump - Carrier 42NL Manuel D'installation

• Refit the valve actuators taking care to ensure that
they are correctly fixed to the valve body.
• Reconnect the flexible water pipes by tightening the
union nuts. Retighten all the water connections and
ensure that all gaskets have been changed and
correctly fitted (maximum torque 15 N·m).
• Open the isolating valves on the manifolds and purge
all air from the system.
• Check that there are no leaks and reconnect the power
to the unit.
WARNING: When replacing a valve always ensure that
the direction of flow through the valve is as shown by the
arrow on the valve body. If the direction of flow is wrong,
the valve body will deteriorate rapidly and the flow control
will be distorted.

4.9 - Flexible pipe option

Minimum bending radius:
• Non-insulated pipes 72 mm
• Insulated pipes 106 mm.
Connections for unit size 2, 3, 4 and 5: 1/2'' diameter (female)
Connections for unit size 6 and 7: 3/4'' diameter (female)

4.10 - Optional electric heater

WARNING: Disconnect the power supply before carrying
out any work on the unit.
If the electric heater develops a fault, it must be replaced;
this requires the removal of the fan motor assembly: Fig. 12.
CAUTION: Do not touch the live metal heater elements
when the electric heater is connected to the power supply.
Electric heater replacement procedure:
• Remove the filter.
• Remove the fan motor assembly access panel.
• Identify and note the fan speeds wired to the auto-
transformer terminal block. Disconnect the power
supply cable.
• Remove the fan motor assembly.
NOTE: Be careful not to touch the fan blades during the
removal process to avoid unbalancing the fans.
• Disconnect the electric heater power supply cables
and remove them through the cable conduit.
• Unscrew the defective heater(s) and replace it (them).
• Replacement of the fan motor assembly is by the
reversal of the above procedure.Carrier Electronic
thermostat type B is embedded with Electric heater
relay 8 Amps. Accordingly, Carrier requires an
additional protection relay for electric heater with
above 1400 W capacity.
All units delivered with an electrical box or a Carrier
controller are always equipped with a relay if the capacity
of the electrical heater is above 1400W.
WARNING : In case of customer supplied controller, it is
the responsability of the installer to set up an additional
protection relay corresponding to the electrical heater
capacity.

4.11 - Optional water sensor

A water temperature sensor can be provided. It has to be
installed on the water circuit as described below :
• For 2-pipe coil : the sensor shall be installed on a
cooling water pipe (for change-over function). The
sensor is installed on a part where the water flow is
continuous.
• For 4-pipe coil : the sensor shall be installed on a
heating water pipe (for cold-draft function that
prevents the operation of the unit when the heating
network is off).
NOTE: In case of unit with an electrical box (for Carrier
Thermostats), a "switch" is provided as an option instead
of the water sensor.

4.12 - Optional condensate pump

Check the sealing of the hydraulic connection of the
condensate pump and condensate recovery.
The meaning of the electrical wires is described below:
• Brown - Blue wires : Electrical supply 230V 50/60Hz
• Black - Grey wires : Alarm contact Normally Closed
(NC) 250V/8A maxi.
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