Optional Water Flow Control Valves; Electric Heater - Carrier 42BJ MCI LEC Installationsanweisungen

Modification procedure
• Disconnect the fresh air duct from the spigot on the
unit.
• Remove or reposition the two plastic restrictors,
following the fresh air flow controller.
• Reconnect the fresh air duct to the spigot.
IMPORTANT: If the 42BJ ICM is fitted with a return air
temperature sensor, the constant fresh air flow rate must
not exceed 50% of the supply air flow delivered by the
unit at minimum speed.
NOTE: To operate correctly, the 8.3 l/s (30 m
fresh air flow controller requires a differential pressure in
the range 50 Pa to 200 Pa. The 16.6 l/s (60 m
fresh air controller requires a differential pressure in the
range 70 to 200 Pa.
4.5.2 - fresh air controller with variable air volume
The 42BJ ICM can be equipped with an optional variable
fresh air flow controller from 0 to 55 l/s (0 to 200 m
This is connected to the numeric Carrier controller and
can regulate the fresh air intake in two ways:
• either using a fixed rate set by the installer that can be
reconfigured as required
• or based on the CO
to a CO sensor via the Carrier numeric controller.
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NOTE: With the variable fresh air flow controller the
upstream pressure in the fresh air duct must be 180 Pa.

4.6 - Optional water flow control valves

These valves are two-way or three-way type, with a body
designed to withstand a 16 bar operating pressure.
4.6.1 - thermoelectric actuator (on/off)
The actuator is a 230 V a.c. on/off type.
NOTE: The thermoelectric actuator is supplied in the
normally closed position for both the two- and the three-
way valve (way A-AB closed for a three-way valve).
To enable the installation to be filled with water, the
water circuits to be equalised and the units to be purged,
the actuators must be connected to the power supply to
open the valves via a command from the wall thermostats
or from the BMS.
4.6.2 - actuator replacement procedure
The actuators on both the chilled water and the hot water
valves may be replaced if either develops a fault.
• Disconnect the power supply to the unit before carrying
out any work on a unit.
• Disconnect the actuator power supply cable equipped
with a quick connector.
• Uncouple the faulty actuator. Refitting is by the
reversal of the procedure described above.
WARNING: Ensure that the actuator is firmly screwed to
the valve body (maximum torque 15 N·m).
/h) constant
3
/h) constant
3
level; in this case it is connected
2
4.6.3 - valve body replacement procedure
• Disconnect the power supply before carrying out any
work on a unit.
• Close the isolating valves on the manifolds.
• Unscrew the union nuts to disconnect the flexible water
pipes.
• Remove the valve actuators taking care to identify the
cooling and heating valves.
• Remove the two-way or three-way water flow control
valve bodies. Depending how the unit is configured, the
three-way valve coupling may be fitted with a heating/
cooling changeover switch, if so do not remove it.
• Fit the new valve body to the coil (fit new gaskets).
• 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
/h). all air from the system.
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• 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.
4.7 - Replacing the electric heater (Fig. 13)
CAUTION: It is vital to disconnect the ICM from the
general power supply before carrying out any work on the

electric heater.

If the electric heater develops a fault, the assembly must be
removed and replaced; the fan unit will have to be removed
to make this possible.
a) Refer to the fan removal procedure.
b) Remove the support assembly and the electric heater
by removing the two screws.
c) Disconnect the electric heater cable (3 wires termina-
ting in flat spade connectors).
d) Release the heater mounting and remove the heater.
e) Replace the defective heater.
f) Use the above procedure in reverse to install the new
heater and to reinstall the fan motor assembly.
WARNING
• Do not touch the heater elements when the heater is
switched on.
• Do not touch the fan wheel during the removal and
re-assembly process.
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