Water Coil; Duct Connection Spigots; Optional Air Filter And Filter Access; Fresh Air Controller - Carrier 42BJ MCI LEC Installation Instructions Manual

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.
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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 environ-
ment 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.
4.5 - Constant-volume fresh air controller
4.5.1 - Constant-volume fresh air controller
The 42BJ ICM can be fitted with a constant fresh air flow
controller allowing the introduction of fresh air and the air
change rate to be controlled.
The following range of fresh air controllers is available:
option a: 8.3 l/s (30 m /h) (-10%; +20%)
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option b: 16.6-44.4 l/s (60-160 m
options a and b: the diameter of the spigot housing the
fresh air flow controller is 125 mm.
The 16.6 1/s (60 m 3 /h) fresh air controller may be modified
on site by relocating or removing two plastic restrictors in
order to increase the maximum constant fresh air flow
capacity to 44.4 1/s (160 m
shows how to adjust the two plastic restrictors (Fig. 11).
/h) (-10%; +20%)
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/h). A label on the 42BJ ICM
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