Carrier 42ET Manuel D'installation, D'utilisation Et D'entretien page 37

4 - COMPONENTS AND MAINTENANCE
4.3 - Water coil
4.3.1 - Water coil removal procedure
WARNING: Disconnect the power supply to the unit
before carrying out any work on the unit.
- Close the isolation valves in the pipework.
- Empty the water in the unit by opening the drain
valve (see Fig. 14).
- Unscrew the union nuts to disconnect the flexible
water pipes.
- Remove the actuator motors, taking care to
identify the cooling and heating valves.
- Disconnect the condensate drain hose held in
place by a collar (not supplied).
- Remove the two-way or four-way water flow
control valve bodies.
- Remove the fan motor assembly access panel
- Loosen the four screws securing the coil
- Pull out the drain pan and the coil
- To replace, follow the above procedure in reverse
order. 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 sealant applied to the valve body.
- Purge all air from the coil during refilling.
NOTE: if necessary, the coil can also be removed
from under the unit along with the drain pan (see
chapter 4.2. "Drain pan removal")
WARNING: Take care when tightening the valve
body to the coils (15 N·m is sufficient) to ensure
they are not damaged.
NOTE: the orientation of the coil cannot be reversed.
4.3.2 - 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.
4.4 - Duct connection rectangular
flanges
When connecting rectangular flanges to the inlet and the
outlet make sure that the duct is in contact with the unit.
4.5 - Filter and access
4.5.1 - Description
The unit is fitted with a G1 filter as standard. As an
option, a G3 filter can also be provided in accordance
with standard EN 779.
The G3 filter complies with the M1 fire class M1 (in
accordance with standard NFP 92-507)
The filters can be accessed in different ways:
• Unit without rectangular flange air inlet (plain
inlet): access is from the rear of the unit.
• Unit with rectangular flange air inlet: access from
underneath (hatch).
4.5.2 - Air filter replacement
Air filters should be changed regularly. Filter life depends
on the rate at which the filter becomes fouled, which
depends upon the cleanliness of the working
environment.
If a fouled filter is not changed it 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 is reduced).
NOTE: when installing a unit in a ceiling void, check
that no T-bars will obstruct filter access and
replacement.
4.6 - Fresh air controller
4.6.1 - Fresh air controller with (adjustable)
constant air volume
The unit can be fitted with three ranges of constant and
adjustable fresh air flow:
15 to 50 m /h, 50 to 100 m
3
The diameter of the spigot housing the fresh air flow
controller is 125 mm.
The fresh air controller may be modified on site. To do
this, unscrew and reposition its damper. See Fig 15.
NOTE: To operate correctly, the constant fresh air
flow controller requires a differential pressure in the
range of 60 Pa to 210 Pa.
4.6.2 - Fresh air filtration
If the unit is provided without a filter or if the fresh air
inlet is fitted in the base unit or in the return plenum, it
is the responsibility of the installer to check whether the
fresh air is filtered beforehand.
/h and 100 to 180 m /h.
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