Carrier Atmosphera 42EM series Manual

42EM
Original document
Ducted fan coil units
INSTALLATION, OPERATION AND
MAINTENANCE INSTRUCTIONS

2
CONTENTS
1 - PRECAUTIONS............................................................................................................................................................................................................................... 9
1.1 - Operating limits............................................................................................................................................................................................................................... 9
1.2 - Clearances required........................................................................................................................................................................................................................ 9
1.3 - Receiving a shipment - installation methods............................................................................................................................................................................... 9
1.4 - Supply voltage 230 V ± 10% - 50 Hz............................................................................................................................................................................................ 9
2 - SAFETY CONSIDERATIONS..................................................................................................................................................................................................... 9
2.1 - General............................................................................................................................................................................................................................................ 9
2.2 - Protection against electrocution................................................................................................................................................................................................... 9
2.3 - General installation conditions................................................................................................................................................................................................... 10
2.4 - Caution for the control of the unit............................................................................................................................................................................................. 10
2.5 - Conformity.................................................................................................................................................................................................................................... 10
3 - INSTALLATION OF THE UNIT................................................................................................................................................................................................ 10
3.1 - Installing the unit in the false ceiling......................................................................................................................................................................................... 10
3.2 - Installation procedure.................................................................................................................................................................................................................. 10
3.3 - Removal procedure...................................................................................................................................................................................................................... 11
4 - COMPONENTS............................................................................................................................................................................................................................. 11
4.1 - Fan motor assembly...................................................................................................................................................................................................................... 11
4.2 - Water coil....................................................................................................................................................................................................................................... 12
4.3 - Duct connection spigots............................................................................................................................................................................................................... 12
4.4 - Optional lter and lter access.................................................................................................................................................................................................... 13
4.5 - Fresh air controller........................................................................................................................................................................................................................ 13
4.6 - Optional water ow control valves............................................................................................................................................................................................. 13
4.7 - Flexible pipe option...................................................................................................................................................................................................................... 14
4.8 - Optional electric heater .............................................................................................................................................................................................................. 14
4.9 - Optional condensate pump (g. 26)........................................................................................................................................................................................... 14
5 - CODIFICATION............................................................................................................................................................................................................................ 15

3
± 0.5% ± 0.5%
0.5 %
1
A
B
C
A
C
B
3
2
45
6
7
9
10
9a
9b
A B C
42EM T0 50 680 250
42EM T1 50 830 250
42EM T2 50 1250 250
42EM T3 50 1250 250
A B C
42EM T0 250 680 250
42EM T1 250 830 250
42EM T2 250 1250 250
42EM T3 250 1250 250
8
10a
10a
1 2 3 4
1 2 3 4
4 3 2 1
4 3 2 1
AB
11
l/s m3/h A B
MR60 17 60 4-4 4-4
MR75 21 75 4-3 4-3
MR85 24 85 3-3 3-2
MR90 25 90 3-2 2-2
MR100 28 100 2-1 2-1
MR105 29 105 2-1 1-1
MR110 31 110 1-1 1-1
MR120 33 120 3-3 -
MR130 36 130 2-1 -
MR140 39 140 1-1 -
MR160 44 160 - -

4
13
14
17
12a
12b
12c
14a
16a
16b
17a 17a
12 16
Hg
Cg
N
N
N
L
L
1
2
3
4
5
6
15
15b
15a
14b
14c

5
32 33 34
28
22 23 24 25 26 27 29 30 31
23
24
20
21
41
42
22
35
36
40
39
38
37
22
L
N
V3
V2
V1
N
18 19
20 21
28
22 23 24 25 26 27 20 21
22
6
5
4
3
2
1
L
7
6
5
4
3
2
1
L

6
81 40
250
18
81 40
250
18
G 1/2”
G 1/2”
4-w V 2-w V
23 42EM
Out
In In
Out
1
2a 3a
1
2b 3b
1
2c 3c
24a
24b 24c
24

7
26
25
27a
27b
27c
27d
27e
27f
27

8
Figure titles and legends:
1 Clearance without return air plenum
2 Clearance with return air plenum
3 Electrical danger pictogram
4 Caution hand hazard pictogram
5 General danger pictogram
6 Lifting unit for installation in a false ceiling
7/8 Levelling the unit
9 Condensate drain pipe
9a 20 mm/m fall in horizontal pipe run
9b 50 mm siphon
10 Several units connected to one condensate collector
10a 20 mm/m fall
11 Freshaircontrollermodication
12 Fan assembly removal
12a Removing fan access panel
12b Position of torx screws
12c Slide assembly down
13 Capacitor assembly
14 Fan speed controller
14a Low speed connector - red wire
14b Medium speed connector - grey wire
14c High speed connector - black wire
L Neutral
15 Optional fan speed terminal block
15a Customer connection
15b Motor
16 Wiring 42EM sizes 22 and 32
16a Motor
16b Auto-transformer
17 Electric heater removal
17a Location of screw
18 Multi-speed bare-wire unit
22 Earth - yellow/green wire
35 Live, electric heater (option) - brown wire
36 Neutral, electric heater (option) - blue wire
37 Neutral - blue wire
38 Low speed - red wire
39 Medium speed - grey wire
40 High speed - black wire
19 Variable-speed bare-wire LEC unit
20 0-10 V - yellow wire
21 GND - blue wire
22 Earth - yellow/green wire
41 Live, 230 V - brown wire
42 Neutral, 230 V - blue wire
23 Electrical heater - Live, 230 V - brown wire
24 Electrical heater - Neutral, 230 V - blue wire
20 Multi-speed unit with control box
22 Earth - yellow/green wire
23 Neutral, 230 V - blue wire
24 Live, 230 V - brown wire
25 Cooling valve actuator - brown wire
26 Heating valve or electric heater actuator
- brown wire
27 Changeover sensor - brown wire
28 Relay
29 Very high speed 1 - black wire
30 Medium speed 3 - red wire
31 Low speed 5 - green wire
32 Very low speed 6 - purple wire
33 Medium speed 4 - orange wire
34 High speed 2 - grey wire
21 LEC unit with control box
20 0-10 V - yellow wire
21 GND - blue wire
22 Earth - yellow/green wire
23 Neutral, 230 V - blue wire
24 Live, 230 V - brown wire
25 Cooling valve actuator - brown wire
26 Heating valve or electric heater actuator
- brown wire
27 Changeover sensor - brown wire
28 Relay
22 Multi-speeds unit with fast connector option -
6 speeds wired
L Neutral, blue wire
1 Speed 1, black wire
2 Speed 2, grey wire
3 Speed 3, red wire
4 Speed 4, orange wire
5 Speed 5, green wire
6 Speed 6, purple wire
7 GND, green/ yellow wire
23 Coil inlet/outlet positions, all sizes
In Water in
Out Water out
4-w V Four-way valves
2-w V Two-way valves
24 Coil drawing with cooling and heating side position
Outlet Water out
Inlet Water in
25 N.m Torque wrenches max
 1Airowdirection
24a Coil size 0x/1x/2x with 4 pipes
2a Cold valves side
3a Hot valves side
24b Coil size 3x with 4 pipes (Right-hand
connection)
2b Cold valves side
3b Hot valves side
24c Coil size 3x with 4 pipes (Left-hand
connection)
2c Hot valves side
3c Cold valves side
25 Meaning of wires - Proportinal valve actuator
25a Black wire (230 V valve actuator), actuator
rod rising
25b Green wire (24 V valve actuator), actuator
rod rising
25c Brown wire, Actuator rod lowering
25d Actuator rod in high position
25e Actuator rod in low position
26 Condensate pump positions
26a Highest pump position
26b Lowest pump position
27 Wiring 42EM sizes 23 and 33
27a Unused speed
27b, 27c, 27d (speeds wiring)
Same wiring colors as Fig. 14 for 3 speeds wired
Same wiring colors as Fig. 20 for all speeds wired
27e Neutral - blue wire
27f Earth - yellow/ green wire

9
English


1.1.1 - Cooling mode
Minimum supply air temperature 12°C when the unit is
installed where the ambient temperature is 27°C dry bulb
with 65% relative humidity.
In steady state, the ambient conditions shall not exceed
27 °C dry bulb temperature and 65% relative humidity.
1.1.2 - Heating mode
Max. supply air temperature = 60°C to avoid damage of
the discharge spigots. To avoid all risks of stratication,
Carrier recommends to keep the supply air temperature
below 35°C.
1.1.3 - Operating environment
The 42EM has been designed for indoor application in
‘urban’ conditions having a non-corrosive, dust-free and
non-marine environment.
The concentrations of the following chemicals must not be
exceeded in any event:
• SO2< 0.02 ppm
• H2S < 0.02 ppm
• NO, NO2< 1 ppm
• NH3< 6 ppm
• N2O < 0.25 ppm
Do not install a unit where ammable gases or products of
an acidic or alkaline character may be present. The copper/
aluminium coil or components inside the unit could suffer
irreparable corrosion damage in their presence.
1.1.4 - Recommended coil water quality
At installation handover, and then periodically every year,
it is advised to analyse the water for bacteria (detection of
ferro-bacteria, H2S-producing and sulphate-reducing
bacteria) and chemicals (in order to avoid problems due to
corrosion and scaling).
The water circuit must include all the necessary elements for
the treatment of the water: lters, additives, intermediate
exchangers, purges, drains, isolating valves, etc., according
to the analysis results.
The results must be in accordance with the values shown
below:
• Total hardness in mmol/l: 1 < mmol/l < 1.5
• Chloride [CL-] < 10 mg/litre
• Sulphate [SO4
2-] < 30 mg/litre
• Nitrate [NO3
-] = 0 mg/litre
• Dissolved iron: < 0.5 mg/litre
• Dissolved oxygen: 4 < [O2] < 9 mg/litre
• Carbon dioxide [CO2] < 30 mg/litre
• Resistivity: 20 Ohm·m < Resistivity
< 50 Ohm·m
• pH: 6.9 < pH < 8
1.2 - Clearances required
Without return air plenum: Fig. 1
With return air plenum: Fig. 2

When receiving a shipment, check the condition of the goods
and report any damage in transit to the shipping company.
Do not unpack the units until just before they are due to
be installed, and make sure they are as close as possible to
the installation site when unpacking them. Do not place
heavy articles of any sort on them.

Check that the supply voltage and frequency correspond
to the values of the unit to be installed.
WARNING: Failure to take proper account of the above
advice and unauthorised modication of the electrical
connections will render the Carrier warranty on the
product null and void.

WARNING: Switch off the main electrical power supply
to the unit and accessories (if installed) before doing any
work on the unit.
2.1 - General
Installing, commissioning and servicing of the various
component (unit, control system, hot and cold water
system, air distribution system) can be dangerous unless
certain aspects of the installation, such as the presence of
mains electricity and hot or cold water in the air
conditioning equipment, are taken into account. Only
specially trained and qualied technicians and installers
who have been fully trained on the product concerned are
authorised to install, commission and service this
equipment.
During servicing work, it is essential to apply all recommen-
dations and instructions given in service leaets, on labels
or in the instructions delivered with the equipment, and to
comply with any other relevant instructions.
Denition of the pictograms used:
• Electrical danger - Fig. 3
• Caution hand hazard - Fig. 4
• General danger - Fig. 5
Comply with all safety rules and regulations currently in
force. Wear eye protectors and work with hand gloves and
any individual protection equipment following local
legislation. Take care when moving or positioning of the
equipment.

Only electricians qualied to the level recommended by the
IEC (International Electrotechnical Commission) in its
standard IEC 364, corresponding to Europe HD 384, France
NFC 15 100 and UK IEE Wiring Regulations, may have
access to electrical components. In particular it is obligatory
to disconnect all power supplies to the unit and its accessories
before carrying out any work. Disconnect the main power
supply with an isolating device (not supplied by Carrier).

10
English
IMPORTANT: The components, which make up the
different control loops described in this manual include
electronic items. As such, they may generate or be harmed
by electromagnetic interference unless they are installed
and used in accordance with these instructions. The
components making up these control systems conform to
the requirements of electromagnetic compatibility in
residential, commercial and light industrial areas. They
also comply with the low-voltage directive.
If the product is supplied without a Carrier control device,
verication of EMC conformity is the responsibility of the
installer.

IMPORTANT: The Carrier numeric controller, power
module, or in general units tted with controls loops must
have an isolating device upstream (for example a double-
pole circuit breaker). If necessary, an easily operated
emergency stop device (such as a punch-button switch)
must cut off the power to all equipment. These safety
devices shall be sized and installed in accordance with
IEC Recommendation 364, corresponding to Europe HD
384, France NFC 15 100 and UK IEE Wiring
Regulations. These devices are not supplied by Carrier.
In general terms the following rules must be applied:

Unit without electric heater T2A
Standard unit sizes 05/09/10/19/21/31 with electric heater T10A
Standard unit sizes 22/23/29/32/33/39 with electric heater T16A
• Units must be provided with over-voltage protection
upstream (not supplied by Carrier). Caution: In LEC
motors the leakage current can reach 3 mA.
• The power disconnection device must be clearly labelled
to identify which items of equipment are connected to it.
• The wiring of the components which make up the
different control systems and the communication buses
must be carried out in accordance with the latest rules
and regulations by professional installers.
• The power supply cable must be doubly insulated and
xed using a cable clamp. A hole is provided for this
purpose in the plastic Carrier controller housing.The
cable must be clamped on the outer insulation.
• The control loop components must be installed in an
environment, which conforms to their index of protec-
tion (IP).
• The maximum level of pollution is normally pollutant
(level 2) and installation category II.
• The low-voltage wiring (communication bus) must be
kept physically separate from the power wiring.
• In order to avoid interference with the communication
links:
- Keep low-voltage wiring away from power cables
and avoid using the same cable run (a maximum of
300 mm in common with the 230 V a.c., 30 A cable).
- Do not pass low-voltage wires through loops in
the power cables.
- Do not connect heavy inductive loads to the same
electrical supply (circuit breaker) used by the
controllers, power modules or speed controllers.
- Use the screened cable type recommended by
Carrier and make sure all cables are connected to
the controllers and power modules.

IMPORTANT: It is not permitted to connect several unit
units to the same control device (electronic NTC
controller, HDB controller, or any other third party
controller). Carrier electronic Thermostat type A&B for
AC motors require additional accessory board to allow
master/slave function. Carrier electronic Thermostat type
C&D for EC motors can be connected upto 10 units, refer
to thermostat installation manual instructions.

This equipment is in compliance with the essential
requirements of the following European directives:
• Electromagnetic compatibility: 2004/108/EEC,
• Low-voltage directive: 2006/95/EEC.


The positioning of the unit must not create an obstacle that
may lead to an unequal distribution and/or return ow of the
air. The ceiling must be sufciently even to allow a simple
installation without danger from the unit. The supporting
structure must be able to carry the unit weight and prevent
deformation, breaks or vibrations during operation.
INSTALLATION PRECAUTIONS: During the installation
process, remove all debris and construction material from
the ducts to prevent any damage to the unit.

•Position the 42EM close to where it is to be installed
in the ceiling void. For installation in a false ceiling use
a hydraulic lift and a folding ladder to make the task
easier (Fig. 6).
• Check that the clearances around the unit are sufcient
to allow easy maintenance. Please refer to the diagram
that shows the service clearances.
• Mark the position of the threaded hangers on the
ceiling (if several units need to be installed, it may be
advisable to produce a drilling template). The method
of xing the threaded hangers (not supplied by Carrier)
depends on the ceiling type (maximum diameter of
the threaded hangers is 10 mm). Once the threaded
hangers are xed to the ceiling, tighten the rst nuts.
WARNING: When moving the units, do not use water
pipes, condensate drain pan, valves or exible pipes to lift
them.
Lift the unit and align it on the threaded hangers, insert
the second nuts and tighten them slightly.
NOTE: At this point do not tighten the nuts fully and do
not clamp the unit up to the ceiling (leave a space between
the ceiling and the unit). The nuts will be adjusted nally,
when the unit has been connected to the pipework and
ducts and levelled.
Level the unit (Fig. 7).
Adjust the hanger nuts so that the unit is inclined 0.5%
towards the condensate drain pan. In the other direction
(air ow direction) the unit must be perfectly level (Fig. 8).

11
English
Condensate drain pipe (Fig. 9): Use a exible pipe with an
inside diameter of 17 mm and provide a constant fall of
20 mm/m (9a) over the whole horizontal pipe run. Install a
50 mm (minimum) siphon (9b) to prevent gases and
odours from owing back into the ceiling void.
WARNING: After drain pipe connection, control
clamping of the drain pipe and be sure there is no water
leakage. If needed, screw the nut of the drain part (inside
the drain pan) by a maximum torque of 1 N.m.
If several units are connected to a common collector, a device
must be installed (Fig. 10). Before operating the unit, ensure
that the water ows into the internal condensate drain pan by
pouring some water into it. If problems are detected, check
the drain pipe slope and look for possible obstructions. In
all cases the connection duct(s) at the unit outlet must be
insulated to prevent any condensate formation on the walls.
NOTE: The pressure losses of these ducts must be compa-
tible with the unit performance. The duct must be as smooth
as possible. Avoid sharp bends. Check that there are no
leaks or kinks, and that there is no dirt or installation
debris inside the ducts. Debris within the ducts might
damage the fan wheel and the damper in the air diffusers.
When installation is complete - i.e. when the 42EM is
attached to the ceiling, air ducts are complete, water
mani-folds are in position with stop valves ready on the
connec-tion stubs, and electrical installation is prepared -
then connect the water pipes (Carrier recommends the use
of exible water pipes that can be supplied as an
accessory). Each exible pipe has a 1/2" gas screw
connector, depend-ing on the model. Ensure that a gasket
(not supplied by Carrier) is installed between the screw
connector and the stop valve.
When all units are installed, open the stop valves on the
manifolds, bleed and then pressurize the circuits. To bleed
the coils, slightly loosen the bleed screws. The installation
can then be started.
NOTE: Do not switch on the power until all connections
are made and earthed.

Switch off the unit power supply at the isolator provided
for the purpose during installation (isolator not supplied
by Carrier).
• Disconnect the power supply and connection cables.
• Close the isolating valves on the manifolds.
• Disconnect the exible water pipes by unscrewing the
gas connectors.
WARNING: Since the exible water pipes do not have
drain valves, a receiver must be provided to allow the
cooling coil to be drained.
• Disconnect the supply air ducts.
• Disconnect the exible condensate drain pipe. Drain
the siphon into a suitable vessel.
• Support the unit lightly and release it by unscrewing
the four nuts on the threaded hangers. Lower the unit
carefully.


4.1.1 - Fan assembly removal procedure
WARNING: Disconnect the power supply to the unit before
carrying out any work on the unit.
Identify and note the wired fan speeds. If the fan develops
a fault the whole assembly must be removed and replaced
(Fig. 12).
• Remove the lter.
• Remove the fan access panel (12a).
• Disconnect the fan assembly power supply cables
(power and control wiring for variable-speed motor).
• If necessary remove the controller (xed with screws)
to gain access to the maintenance screws of the panel
supporting the fan.
• The fan assembly and its panel are held in place by
four torx screws (T20) (12b). Remove these screws
and slide the assembly down (12c).
• Remove the fan motor assembly.
NOTE: Be careful not to touch the fan blades during
the removal process to avoid unbalancing the fans.
• For units with the electric heater option, disconnect
the power supply cable to the heater.Withdraw the
cable through the cable gland.
• Unscrew the electric heaters.
• Replacement of the fan motor assembly is by the
reversal of the above procedure.
WARNING: The electrical connections to the fan motor
must be made in accordance with the labels on the
con-nector block.
For the variable-speed motor carefully separate the power
wiring cable from the control wiring cable and pull them
apart as far as possible.
4.1.2 - Capacitor replacement procedure (Fig. 13)
• Disconnect the power supply to the unit before
carrying any work on the unit.
• Remove the lter.
• Remove the fan motor assembly access panel.
• Remove the capacitor that is attached to the motor
chassis assembly.
• Disconnect the capacitor by withdrawing the at spade
connectors from the back of the capacitor.
• Replacement of the capacitor assembly is by the reversal
of the above procedure.
4.1.3 - Fan wiring
4.1.3.1 - Multi-speed unit with bare wires - 3 speeds wired
The fan motor has six speeds, provided by an auto-trans-
former, offering the unit greater ow control exibility.
Three of the six speeds must be selected to allow connection
of the fan motor in accordance with the applicable electronic
regulations (minimum speed = 6, maximum speed = 1). See
Fig. 14.

12
English
The three speeds are connected to a ve-pole Wego
connector - see Fig. 18.
Speed wiring modication
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

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.

4.2.1 - 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 exible
water pipes.
• Remove the valve actuators taking care to identify the
cooling and heating valves.
• Disconnect the exible condensate drain pipe held in
place by a collar (the collar is not supplied by Carrier).
• Remove the two-way or four-way water ow control
valve bodies. Depending on the unit congura-tion the
four-way valve coupling may be tted with a heating/
cooling changeover switch. If so, do not remove it.
• Loosen the four xing 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 tted) 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 relling.
ATTENTION: Take care when tightening the valve body to
the coils (15 N·m is sufcient) 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.

These are manufactured from high density plastic with a
VO re rating, more or less equivalent to class M1 (French
standard). They are encased inside the unit. The ducts
should be xed 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.

13
English

4.4.1 - Description
The Carrier unit is tted with G3 lter as standard (85%
gravimetrie lter) or G4 lter as option, according to
standard EN 779. Medium re rating M1, metal wire
frame.
Different lter access are available:
• Unit with non-ducted return air: Access is from the
rear of the unit.
• Unit with ducted return air: Access is from below.
4.4.2 - Air lter replacement
Air lters should be changed regularly. Filter life depends on
the rate at which the lter becomes clogged, which depends
upon the cleanliness of the working environment.
If clogged lters 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 ow reduces).
NOTE: When installing a unit in a ceiling void, check
that no T-bars will obstruct lter access and removal.

4.5.1 - Fresh air controller with constant air volume
The 42EM unit can be tted with a constant fresh air ow
controller, xed at 8.5 l/s (30 m3/h) or adjustable from 17 l/s
(60 m3/h) to 44 l/s (160 m3/h) to allow contol of the
introduction of fresh air and of the air change rate.
Controllers with adjustable fresh air ow:
The diameter of the spigot housing the fresh air ow
controller is 125 mm.
The fresh air controller may be modied on site by relocating
or removing two plastic restrictors in order to change the
maximum constant fresh air ow of 17 1/s (60 m3/h) to 44 1/s
(160 m3/h). A label on the 42EM shows how to adjust the
two plastic restrictors (Fig. 11).
Modication procedure
• Disconnect the fresh air duct from the spigot on the
unit.
• Remove or reposition the two plastic restrictors,
following the fresh air ow controller.
• Reconnect the fresh air duct to the spigot.
IMPORTANT: If the unit is tted with a return air
temperature sensor, the constant fresh air ow rate must
not exceed 50% of the supply air ow delivered by the
unit at minimum speed.
NOTE: To operate correctly, the 8.5 l/s (30 m3/h) the
constant fresh air ow controller requires a differential
pressure in the range of 50 Pa to 200 Pa. The controller with
adjustable fresh air ow from 17 l/s (60 m3/h) to 44 l/s
(160 m3/h) requires a differential pressure in the range of
70 to 200 Pa.
4.5.2 - Fresh air controller with variable air volume
The 42EM unit can be equipped with an optional variable
fresh air ow controller from 0 to 55 l/s (0 to 200 m3/h).
This is connected to the numeric Carrier controller and can
regulate the fresh air intake in two ways:
• Either using a xed rate set by the installer that can be
recongured as required
• Or based on the CO2level; in this case it is connected
to a CO2sensor via the Carrier numeric controller (the
CO2 sensor is located opposite the fresh air inlet).
NOTE: With the variable fresh air ow controller the
upstream pressure in the fresh air duct must be 180 Pa.

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 16 bar operating pressure.
With this option, the couple (valve + actuator) is usually
normally closed (NC).Thus, the water ow is null in case of
power cut. To ll the installation, to equalise 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 ‘‘4.6.3. - Actuator replacement procedure’’.
4.6.1 - 230 V - Actuators
Two types of valve actuators are provided : electrothermal
actuator (on/off control) or modulating actuator (3-point).
The actuator supply is 230 V a.c.
4.6.2. 24 V - Actuators
Three types of valve actuators are provided : one
electrothermal actuator (on/off control) or two modulating
actuators (3-point or 0-10V).
Both modulating actuators can be operated manually with a
hexagonal key. The 0-10V command voltage range of the
modulating actuator can also be adjusted.
The actuator supply is 24 V a.c.
NOTE: 24V actuators are not compatible with Carrier
controllers (Thermostats A/B/C/D, HDB & NTC).
4.6.3 - Actuator replacement procedure
The actuators on both the chilled water and the hot water
valves may be replaced if either develops a fault.
WARNING : Do not connect on the same neutral wire the
valve actuator 24 Vac and the controller.

14
English
• Disconnect the power supply to the unit before carrying
out any work on a unit.
• Disconnect the actuator power supply cable.
- 230 V type actuator used with the Carrier
numeric controller: Disconnect the actuator
power supply cable tted with a quick connector.
- 230 V actuator used with an electronic
thermostat: Remove the plastic protection cover
held in place with two screws. Disconnect the
actuator power supply cable connected to the
quick connector.This can be done by pressing
down the spring tongue using a screwdriver and
pulling out the wire from the appropriate terminal.
• Uncouple the faulty actuator. Retting is by the reversal
of the procedure described above.
WARNING: Ensure that the actuator is rmly screwed to
the valve body (maximum torque 15 N·m).
4.6.4 - Valve body replacement procedure
• Disconnect the power supply before carrying out any
work on a unit.
• Close the isolating valves on the manifolds.
• Unscrew the union nuts to disconnect the exible water
pipes.
• Remove the valve actuators taking care to identify the
cooling and heating valves.
• Disconnect the exible condensate drain pipe which is
held in place by a collar (the collar is not supplied by
Carrier).
• Remove the two-way or four-way water ow control
valve bodies. Depending how the unit is congured,
the four-way valve coupling may be tted with a
heating/cooling changeover switch, if so do not
remove it.
• Fit the new valve body to the coil (t new gaskets).
• Reconnect the exible condensate drain pipe which is
held in place by a collar (the collar is not supplied by
Carrier).
• Ret the valve actuators taking care to ensure that
they are correctly xed to the valve body.
• Reconnect the exible water pipes by tightening the
union nuts. Retighten all the water connections and
ensure that all gaskets have been changed and correctly
tted (maximum torque 15 N·m).
• Open the isolating valves on the manifolds and purge
all air from the system.
• Check that there are no leaks and reconnect the power
to the unit.
WARNING: When replacing a valve always ensure that
the direction of ow through the valve is as shown by the
arrow on the valve body. If the direction of ow is wrong,
the valve body will deteriorate rapidly.

Minimum bending radius:
• non-insulated pipes 72 mm
• insulated pipes 106 mm.
electric heater
WARNING: Disconnect the power supply before carrying
out any work on the unit.
If the electric heater develops a fault, it must be replaced;
this requires the removal of the fan motor assembly: Fig. 17
(17a = screw).
CAUTION: Do not touch the live metal heater elements
when the electric heater is connected to the power supply.
Electric heater replacement procedure:
• Remove the lter.
• Remove the fan motor assembly access panel.
• Identify and note the fan speeds wired to the auto-
transformer terminal block. Disconnect the power
supply cable.
• Remove the fan motor assembly.
NOTE: Be careful not to touch the fan blades during
the removal process to avoid unbalancing the fans.
• Disconnect the electric heater power supply cables
and remove them through the cable conduit.
• Unscrew the defective heater(s) and replace it (them).
• Replacement of the fan motor assembly is by the
reversal of the above procedure.
WARNING : Carrier Electronic thermostat type B and D
are embedded with Electric heater relay 8 Amps.
Accordingly, Carrier requires an additional protection
relay for electric heater 2000W and 3200W.
WARNING : In case of customer supplied controller,
Carrier recommends to set up an additional protection
relay corresponding to the electric heater capacity.

According to the g. 26, the condensate pump installation
require the following actions:
• Press the pump at the lowest position according to the
available height in the false celling (g. 26b)
• Check the sealing of the hydraulic connection of the
condensate pump and condensate recovery
The meaning of the electrical wires is described below:
• Brown - Blue wires : Electrical supply 230V 50/60Hz
• Black - Grey wires : Alarm contact Normally Closed
(NC) 250V/8A maxi

15
English
W


-Withoutlter
V G3
W G4
- Without
RIGHT
A 125 mm ø fresh air spigot only
B 8.5l/s (30 m3/h)
C 17-44 l/s (21/28/36) 60-160 m3/h
(75/100/130)
E Motorised fresh air valve adapter ø
125 mm
J 125 mm ø fresh air spigot only
LEFT
K 8.5l/s (30 m3/h)
L 17-44 l/s (21/28/36) 60-160 m3/h
(75/100/130)
N Motorised fresh air valve adapter ø
125 mm
- Without
ANTC
B HDB
C Without + Plastic cover alone
D NTC + IAQ card
E Terminal block 6 speeds with plastic box
F E + relay
G E + relay + fuse holder
K NTC + fuse holder
L NTC + IAQ card + fuse holder
M HDB + fuse holder
N Without + fuse holder
P Without + relay
Q Without + fuse holder + relay
R E + fuse holder
S Electric box
T S + fuse holder
U S + relay
V S + fuse holder + relay
W C + fuse holder
X C + relay
Y C + relay + fuse holder
2 Without ( 6 speeds)
3 Without + Plastic cover alone ( 6 speeds)
4 Without + fuse holder ( 6 speeds)
5 Without + relay ( 6 speeds)
6 Without + fuse holder + relay ( 6 speeds)
7 3+ fuse holder ( 6 speeds)
8 3 + relay ( 6 speeds)
9 3+ relay + fuse holder ( 6 speeds)
B Modular unit with 2 supply air spigots
C Modular unit with 3 supply air spigots
G Modular unit with 1 supply air spigot at the end
(in-lineconguration)
H Modular unit with 1 supply air spigot at the side
(opposite coil)
J Modular unit with 4 supply air spigots
K Modular unit with 5 supply air spigots
M Return air plenum 1 spigot and modular unit 1 supply
airspigot(in-lineconguration)
N Return air plenum 1 spigot and modular unit 1 supply
airspigot(U-shapeconguration)
P Return air plenum 2 spigots and modular unit 2
supply air spigots
Q Return air plenum 3 spigots and modular unit 3
supply air spigots
R Return air plenum 4 spigots and modular unit 4
supply air spigots
S Return air plenum 5 spigots and modular unit 5
supply air spigots
T Compact unit with 1 return air spigot and 1 supply air
spigot
U Compact unit with 2 return air spigots and 2 supply
air spigots
V Compact unit with 3 return air spigots and 3 supply
air spigots
NOTE: Terminal 1 = highest speed, Terminal 6 = lowest speed.
Fan set
Codication(lastdigit)
or option 600
Red wire
Grey wire
Black wire
Wire marked L
Terminal marking (standard wiring), option 600 not selected
and option 570 = NTC or HDB
A 2 pipes right
B 2 pipes left
C 4 pipes right
D 4 pipes left
L 2 pipe/2 wire right 1 x 500W (42 EM
05/09/10/19)
M 2 pipe/2 wire left 1 x 500W (42 EM
05/09/10/19)
N 2 pipe/2 wire right 1 x 800W (42 EM
05/09/10/19)
P 2 pipe/2 wire left 1 x 800W (42 EM
05/09/10/19)
Q 2 pipe/2 wire right 1000W (1 x 1000
42EM 05/09/10/19 & 2 x 500 42EM
21/22/23/29/31/32/33/39 )
R 2 pipe/2 wire left 1000W (1 x 1000
42EM 05/09/10/19 & 2 x 500 42EM
21/22/23/29/31/32/33/39 )
S 2 pipe/2 wire right 1600W (1 x 1600
42EM 05/09/10/19 & 2 x 800 42EM
21/22/23/29/31/32/33/39 )
T 2 pipe/2 wire left 1600W (1 x 1600
42EM 05/09/10/19 & 2 x 800 42EM
21/22/23/29/31/32/33/39 )
U 2 pipe/2 wire right 2000W (2 x 1000W
42EM 22/23/29/32/33/39)
V 2 pipe/2 wire left 2000W (2 x 1000W
42EM 22/23/29/32/33/39)
W 2 pipe/2 wire right 3200W (2 x 1600W
42EM 22/23/29/32/33/39)
X 2 pipe/2 wire left 3200W (2 x 1600W
42EM 22/23/29/32/33/39)
0
0
5
9
1
1
0
9
2 1
2 2
2
2
3
9
3 1
3 2
3
3
3
9
Product type Size
Modication code Coils Supply and return air plenum Valves Valve motors Control Sensors Filter and access Fresh air Motor wiring
Product reference 4 2 E M 0 5 E A T - 0 - - B - Q
Digit 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16
{
Variable-speed
LEC motor
- Without
A Condensate pump
B 2-way valve + condensate pump
C 2-way valve
D 4-way valve
E 4-way valve + condensate pump
F2-wayvalve+exiblepiping+
condensate pump
G4-wayvalve+exiblepiping+
condensate pump
J2-wayvalve+exiblepiping
K 4-wayvalve+exiblepiping
- Without
A230Von/o
B24Von/o
C 230 V 3 points
D 24 V 3 points
E24 V (modulating 0-10 V)
- Without
A Return air sensor
B Supply air sensor
C Change-Over water sensor
D A + B
E A + B + C
F A + C
G B + C
H CO2sensor
J A + CO2
K B + CO2
L C + CO2
M A + B +CO2
N A + C + CO2
P B + C + CO2
Q A + B + C + CO2

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Order No: 14226, 01.2015 - Supersedes order No: 14226, 11.2014. Printed in the European Union.
Manufacturerreservestherighttochangeanyproductspecicationswithoutnotice.