12
English
The three speeds are connected to a five-pole Wego
connector - see Fig. 18.
Speed wiring modification
ON a unit supplied with bare wires, the speeds are pre-
wired at the factory, as ordered.
To modify the wiring, change the speeds at the auto-
transformer inside the unit. See Fig. 14.
4.1.3.2 - Multi-speeds unit with fast connector option - 6
speeds wired
This option enables to get six speeds from the AC fan
motor available through a fast connector. Refer to Fig. 22.
4.1.3.3 - Multi-speeds unit with control box option
This option allows the installer to connect the unit to a
terminal board inside a control box. To comply with the
applicable regulations, the control box can be opened with
a screw driver.
Three of the available six speeds are connected - the
default factory wiring is 5-3-1 (minimum speed = 6,
maximum speed =1).
The control box option permits changing the speed wiring
without access to the motor. See Fig. 20.
4.1.3.4 - Variable-speed bare-wire LEC unit
Connection of the 230 V a.c. fan motor power supply is at a
three-point Fast connector. Connection of the 0-10 V d.c.
control signal is at a two-point Fast connector. See Fig. 19.
4.1.3.5 - Variable-speed LEC unit with control box option
This option allows the installer to connect the unit to a
terminal board inside a control box. To comply with the
applicable regulations, the control box can be opened with
a screw driver.
The 0-10 V d.c. signal that controls the variable fan speed
is directly accessible at the terminal board. See Fig. 21.
4.1.4 - Wiring precautions during replacement of a fan
motor on sizes 22, 23, 32, 33 with a.c. motor
During replacement of the a.c. fan motor, the installer
must wire the speeds in accordance with the instructions in
the table below:
Wiring for 42EM 22 and 42EM 32: Fig. 16
42EM sizes 22 and 32
Neutral (com)
1
White
Phase connected 2
Red
Wiring legend:
Minimum speed = Terminal 6
Medium speed = Grey wire (14b)
Maximum speed = Terminal 1
High speed
= Black wire (14c)
Low speed
= Red wire (14a)
L
=
Neutral
Wiring for 42EM 23 and 42EM 33: See Fig. 27.
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 held in
place by a collar (the collar is not supplied by Carrier).
•
Remove the two-way or four-way water flow control
valve bodies. Depending on the unit configura-tion the
four-way valve coupling may be fitted with a heating/
cooling changeover switch. If so, do not remove it.
•
Loosen the four fixing screws (4 torx screws (T20)).
Pull out the drain pan and coil assembly (the drain pan
remains attached to the unit for approximately 100 mm)
until the coil is completely detached. Then remove the
coil from the drain pan.
•
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: Take care when tightening the valve body to
the coils (15 N·m is sufficient) to ensure they are not
damaged.
NOTE: The coil connection can be changed on site by
changing the condensate pan and coil assembly in the guides.
For size 3 the water inlet and outlet need to be reversed to
achieve the published performance.
4.2.2 - Coil inlet/outlet and cooling/heating side positions
Water inlets/outlets, all sizes : Fig. 23.
Coil drawing with cooling and heating side position: Fig 24.
ATTENTION: Carefully observe the direction indicated
by the arrow on the valves, based on the valve type.
4.3 - Duct connection spigots
These are manufactured from high density plastic with a
VO fire rating, more or less equivalent to class M1 (French
standard). 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.
