Carrier 42 GW Serie Manual De Instalación página 28

Motorized valve and control
Motorized thermo-electric valve assembly and components
(See fig. 28).
Mod. 42GW
Ref. Description
a Adaptor 3/4 " gas with O-ring
Adaptor 1" gas with O-ring +
Adaptor 3/4" gas with O-ring +
b Self tapping screw
c
Clip
d
Valve 1" gas pre-assembled
Valve 3/4" gas pre-assembled
Valve 1/2" gas pre-assembled
e
Auxiliary drain pan
f
Insulating material
g Cable holder
Instructions for mounting of motorized
thermo-electric valve assembly
(see "Components" table)
• The thermo-electric valve must be mounted on the unit after
the unit installation.
For this operation follow figures, depending on model.
• Insert the clips supplied in the unit side slots (See fig. 29)
Assembly
For models 42GWD (4-pipe), the valve assembly for the
cold water coil must be installed first (See fig. 30).
Gently grease the O-rings before fitting them into their
seats.
• Connect the valve assemble to the coil and fix it by a 30Nm
torque.
• Insulate the valve assembly.
• For 4-pipe hot water coil, repeat all the operations with gas
adaptors, as per the table.
• Pass cables through the cable holder G and fix them to the
case using the already pre-assembled screws.
• Mount the drain pan below the valve assembly, inserting the
discharge pipe into the special hole; align and fix it to the 3
clips previously assembled using the three screws supplied.
• Insulate the 3 screws and the drain pan lower part using the
insulating material F.
• To connect the steel pipes to the system, ensure they are
aligned and supported to avoid excess strain on the unit. If
the system is filled with water, check all fitting seals.
NOTE:
The seal efficiency of the valve assembly is factory tested.
Any system losses are therefore due to an incorrect
installation.
Electric connections
• To connect valves to the electric panel pass cables through
the electric panel grommet and connect them to the terminal
26 42 GW
004 012 004 020
008 016 008
010 020 010
2-pipe 4-pipe
q.ty q.ty q.ty q.ty
2
2+
2
3 3 3 3
3 3 3 3
1 1
1 1 1
1
1 1 1 1
1 1 1 1
1 1 1 1
board TB3 as per the wiring diagrams.
Operation of the thermo-electric valve (See fig. 31)
• This 3-way valve is an ON-OFF type with a very slow stroke.
It is not a modulating valve so it has no PTC.
This valve is driven, as a sensible element, by the ambient
thermostat of the "cassette" unit.
• The thermo-electric valve is normally closed towards the coil
and open towards the bypass.
When the room temperature does not satisfy the thermostat,
an electric heater activates the heating of a thermostatic
element which causes the down-stroke of the piston; the
valve opens after about 3 minutes about to allow water to
circulate in the coil.
• If the room temperature satisfies the thermostat or if the
electric power has been switched off, the valve is closed after
about 3 minutes towards the coil and is opened towards the
bypass.
• If an emergency occurs, the valve may be manually opened,
removing the electric head, unscrewing the ring nut.
When the emergency ends, remember to reset the valve to
automatic operation, repositioning the electric head;
failure to do this can result in condensate formation due
the water pipes, even if the unit is switched off.
Instructions for field supplied valves
Water connection
• Install valves following manufacturer's instructions; refer to the
relevant figures for connection to the unit.
• Carefully insulate pipes, valve assemblies and coil connections
(cold water side) to avoid condensation forming on the pipes
and dripping on the false ceiling.
Electrical wiring
• Connect the room control following instructions for the control
used.
WARNING:
Pass cables through the control panel cable-conduit.
• Connect valves as per the following instructions, using the
wiring diagram in this chapter (See fig. 42)
• Valves, closing the unit water inlet when there is no
power supply, must be used.
ON-OFF valves (230V)
• In this case the cold water valve must be controlled by the ON-
OFF signal from terminal 1 of TB3 and the hot water valve from
terminal 2 of TB3.
ON-OFF valves with other voltages than 230V (See fig. 33)
• If a room control listed in the accessories table is used, follow
the instructions in the previous paragraph and install two
230V relay at TB3 terminals 1, 2, 4 and 5 which will control
the valve opening.
• If a low voltage control is used or if the control is not listed in
the accessories table, the connections must be made on the
unit terminal board (See fig. 34).