Components; Fan Motor Assembly; Water Coil; Duct Connection Spigots - Carrier 42BJ Installation Instructions Manual

Mci lec sizes : 1.9-2.9-4.9. individual comfort module for variable air volume systems
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4 - COMPONENTS

4.1 - Fan motor assembly

4.1.1 - Description
The ICM has a double inlet high static pressure fan motor
assembly.
The low energy consumption motor uses a 230 V ± 10%, 50 Hz
single-phase power supply and runs at variable speed under the
control of a Carrier numeric controller supplying 0-10 V control
signal.
4.1.2 - Fan motor assembly removal procedure
WARNING: Disconnect the power supply to the unit before
carrying out any work on the unit.
If the fan develops a fault the whole assembly must be removed
and replaced.
- Remove the fan access panel (12a).
- Disconnect the fan motor assembly power supply cables
equipped with quick connectors (power and control wiring).
- Disconnect the electric heater supply cable from the 42BJ.
The cable has three wires terminating in flat spade
connectors.
- The fan motor and its support are held in place by one screw
(12b) and three lugs. Remove this screw and slide the
assembly free of the lugs.
- Remove the fan from its support panel (4 screws - 12c).
- Replace the fan motor assembly and follow the procedure in
reverse order.
WARNING: To reconnect the motor cables separate the power
wiring cable from the control wiring cable and pull them apart
as far as possible.

4.2 - Water coil

4.2.1 - Coil removal procedure
WARNING: Disconnect the power supply to the unit before
carrying out any work on the 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.
- Disconnect the flexible condensate drain pipe which is held
in place by a collar (the collar is not supplied by Carrier).
- Remove the two-way or three-way water flow control valve
bodies. Depending how the 42BJ ICM LEC is configured, the
three-way valve coupling may be fitted with a heating/cooling
changeover switch, if so do not remove it.
- Remove the 4 torx screws (T20) and slide out the coil and
drain pan assembly.
- Replacement is by the reversal of the procedure des-cribed
above. Ensure that all gaskets are changed (new gaskets
fitted) and that the inlet and outlet connections to the coil are
made correctly using an appropriate sealing compound
applied to the valve body.
- Bleed all air from the coil during refilling.
ATTENTION: It is advisable to tighten the valve body to the
coils with caution (15 N·m is sufficient) to ensure they are not
damaged.
4.2.2 - Coil inlet/outlet positions (Fig. 15)
Water inlets/outlets, sizes 1.9/2.9.
Water inlets/outlets, size 4.9.
ATTENTION: Carefully observe the direction indicated by the
arrow on the valves, based on the connection side and the
valve type.

4.3 - Duct connection spigots

These are manufactured from high density plastic with a VO fire
rating. They are encased inside the unit. The ducts should be fixed
to these spigots using circular collars or adhesive. Screws and
rivets should not be used.
WARNING: In order to guarantee good air tightness, the duct
should overlap the whole of the spigot.
Make sure that the maximum supply air temperature does not
exceed 60°C.
Do not lift or support the unit using the spigots, place loads on the
spigots or damage the spigots during installation or operation.
4.4 - Optional air filter and filter access: air
filter replacement
Air filters should be changed regularly. How often this is needed
depends on the cleanliness of the working environment and the
rate at which the filter becomes clogged.
If clogged filters are not changed they can increase the pressure
drop, trapped dust particles may be given off and entrained in the
air supply, and the general performance of the ICM may be
degraded as the air flow reduces.
NOTE: The condensate drain pan is located at the suction
end of the fan, and could therefore overflow if the air filter
became clogged. This is because the partial vacuum inside
the unit could stop the condensate from draining normally.
Access from the side (Fig. 1c)
To access the filter, open the latch, open the hinged access door
and remove the filter from its housing by releasing the two clips
which hold it in place.
When replacing the filter, make sure that the sealing gasket is
against the internal metal housing.
Access from above or below (Figs. 1a and 1b)
In these situations the filter is installed in a removable plug-in unit.
To replace the filter assembly, disengage the two latches and
withdraw the plug-in unit. Remove the old filter and insert a new
one ensuring that the sealing gasket is against the internal metal
housing.
NOTE: When installing an ICM in a ceiling void, check that
no T-bars will obstruct access to the filter or prevent the plug-
in unit from being withdrawn.
11

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