Spigots Duct Connection; Rectangular Flanges Duct Connection; Optional Filter And Filter Access; Fresh Air Controller - Carrier 42EP Installation, Operation And Maintenance Instructions

4 - COMPONENTS AND MAINTENANCE
- After replacement, 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.
WARNING: Take care when tightening the valve
body to the coils (15 Nm is sufficient) to ensure they
are not damaged.
CAUTION: Coil inlet/outlet and cooling/heating side
positions
Water inlets/outlets, all sizes: Fig. 14.
WARNING: Carefully observe the direction indicated
by the arrow on the valves, based on the valve type.

4.5 - Spigots Duct connection

These are manufactured from aluminium sheet metal.
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 during installation or operation.
4.6 - Rectangular flanges duct
connection
When connecting rectangular flanges to the inlet and
the outlet make sure that the duct is pushed closely the
unit.

4.7 - Optional filter and filter access

4.7.1 - Description
The Carrier unit is fitted with G3 filter as standard. The
G3 filter is compliant to M1 fire rating (according to NFP
92-507 standard).
4.7.2 - Air filter replacement
Air filters should be changed regularly. Filter life depends
on the rate at which the filter becomes clogged, which
depends upon the cleanliness of the working
environment.
If clogged filters are not changed they can increase the
air pressure drop, trapped dust particles may be given
off and entrained in the air supply, and the general
performance of the unit may be degraded (as the air
flow reduces).
- Remove the filter access door in case of units with
inlet plenums and take out the filter.
- Remove the filter directly in case of no plenum
18
NOTE: When installing a unit in a ceiling/floor void,
check that no T-bars will obstruct filter access and
removal.

4.8 - Fresh air controller

4.8.1 - Fresh air controller with (adjustable)
constant air volume
The unit can be fitted with three ranges of constant and
adjustable fresh air flow. The 3 ranges are 15 to 50 m
50 to 100 m 3 /h and 100 to 180 m
The diameter of the spigot housing the fresh air flow
controller is 125 mm. The fresh air controller can be
modified on site by unscrewing and repositioning the
damper of the controller. See fig 17.
IMPORTANT: If the unit 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 constant fresh air
flow controller requires a differential pressure in
the range of 60 Pa to 210 Pa.
4.8.2 - Fresh air controller with variable air
volume
The unit can be equipped with a 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 using a fixed rate set
by the installer that can be reconfigured as required.
NOTE: With the variable fresh air flow controller the
upstream pressure in the fresh air duct must be 180
Pa. It is available as an accessory.
4.8.3 - Fresh air filtration
If the unit is provided without any filter or in the return
plenum, it is the responsibility of the installer to check
if the fresh air is filtered beforehand.

4.9 - Optional water flow control valves

These valves are either two-way or four-way type (three-
way with integral bypass). The body of the valve is
designed to withstand a 15,5 bar (1550 kPa) bar
operating pressure.
With this option, the couple (valve + actuator) is usually
normally closed (NC).Thus, the water flow is null in case
of power cut. To fill the installation, to equalize the water
circuits and to purge the units, the actuators must be
connected to the power supply and the valves must be
opened via the controller (thermostats or BMS).
For the replacement of these components refer to the
chapter 4.9.4.
3 /h,
3 /h.
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