Motorized Valve And Control - Carrier 42 GW Installationsanweisung

Motorized valve and control

• The unit control circuit only allows opening of the motorized valve
when the fan motor is working.
• When a lower temperature is required by the thermostats, the
outlet V and H (terminal blocks ref.20) is powered at 230V and the
corresponding chilled water or hot water valve is energized
WARNING :The pump control circuit stops water supply to the
cold valve if an irregular increase of the condensate water level
is detected into the drain pan
• If an irregular increase of the condensate water level is detected
into the drain pan (for example: possible defective drain, pump
malfunction, fan motor not working) the contact of the "safety level
2" float switch opens to close the regulation valve, stopping the cold
water flow towards the coil and avoiding further condensation.
Control
• The water flow has to be controlled:
• by installing the motorized thermo-electric valves supplied a accessory
or
• by installing motorized field supplied valves.
Motorized thermo-electric valve assembly and components
(See fig. 28).
Mod. 42GW
Ref. Description
a Actuator
Valve 1"gas
b Valve 3/4" gas
Valve 1/2" gas
c Shell
d Clips
e Gasket
Instructions for mounting of motorized thermo-
electric valve assembly
• The thermo-electric valve must be mounted on the unit after the unit
installation. For this operation follow figures, depending on model.
Assembly (Fig. 30)
With 4–pipes models, first install the valve assembly for the cold
circuit followed by the valve assembly for the hot circuit.
Connect the valve assemble to the coil and fix it by a 30Nm torque.
Insulate the valve assembly.
Gasket type
Rubber
Fibre
Fit the actuator on the valve body, route the valve cable through the
box and connect it to the terminal block as shown in fig. 37.
• 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.
• After ending the hydraulic connections, make sure there are no leaks
Insulate the valve using the shell, fix it by means of the clips and make
sure that all cold parts are insulated (fig. 29 – 30).
• For 4-pipe hot water, repeat all the operations with gas adaptors, as
per the table.
32 42 GW
200 500 200 700
300 600 300
400 700 400
2-pipe 4-pipe
q.ty q.ty q.ty q.ty
1 1 2
1
1 1
1
1 1 1
3 3 3
2 2 4
(see "Components" table)
Nm
10/12
25/30
NOTE:
The seal efficiency of the valve assembly is factory tested. Any
system losses are therefore due to an incorrect installation.
Operation of the thermo-electric valve (See fig. 31)
• This 2- 3-way valve is of the OPEN/CLOSE type with very slow travel.
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 2-way valve is normally closed to the coil with no powered
actuator side. The 3-way valve is normally closed to the coil with no
powered actuator side while is open to the bypass way side. When the
room temperature does not satisfy the thermostat, 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
2
on the false ceiling.
1
Electrical wiring
1
• Connect the room control following instructions for the control used.
1
ATTENTION: Route the cables through the electrical box as shown
in fig. 37.
3
4
• Connect the valves according to the instructions and the wiring
diagrams attached to the machine documents.
• Valves, closing the unit water inlet when there is no power supply,
must be used.
•
ON-OFF valves (230V)
• The chilled water valve must be operated by the 230V on-off signal
from terminal V and the hot water valve from terminal H.
• If these connections are not made as described the drain pan
condensate may overflow.
• Valves should open only when the fan is working, that is, when one of
terminals V1, V2, V3 is energized by L mains supply.
• When the system is filled with water, verify all couplings for
tightness.
• The manufacturer does not accept responsibility for the tightness
of the field - installed valve assembly and this is not tested in the
factory.
• He declines any responsibility for non functioning of these
assemblies and for damage due to dripping.