Carrier 42NH series, Installation, Operation And Maintenance Instructions, Page: 23 / 92

23
ENGLISH
4.8.1 - Optional balancing valves
Two-way valve with waterflow balancing function is
embedded with a differential pressure controller (with or
without pressure test points to control the waterflow
settings). The setting of the valve is shown in Fig. 16.
The manual control knob (16a) is ready fitted to protect
valve stem and pre-set mechanism and facilitates manual
control of valve during commissioning.
Setting procedure:
•
Remove control knob from the valve (16a)
• Loosen knurled nut (16b).
• Adjust the desired dial setting with the white knob
(16c) - see table below.
• Retighten knurled nut by hand (16d).
Waterflow to adjust [l/h]
1/2’ valve
Not
Standard
3/4’ valve Available
1’’ valve Available Available
ON/OFF
actuator
Not
Standard Available Available
Moduling /
3p actua.
Not
Standard Available
Available
Waterflow range : 200l/h (*) 600l/h (*) 1200l/h (*) 1600l/h (*)
Dial Setting
Min NA NA NA NA
0.2 NA NA NA NA
0.4 NA NA NA NA
0.5 30 100 NA NA
0.6 35 115 200 220
0.8 40 130 260 290
1 50 160 310 250
1.2 60 180 380 420
1.4 70 210 430 480
1.6 80 240 490 550
1.8 90 270 550 610
2 100 300 610 680
2.2 110 320 660 740
2.4 120 350 730 810
2.6 130 380 780 870
2.8 140 410 840 940
3 150 440 900 1000
3.2 160 460 960 1070
3.4 170 490 1010 1130
3.6 180 520 1070 1200
3.8 190 550 1130 1260
MAX 200 575 1190 1330
(*) : Maximum specified water flow on the valve body
WARNING: The valves have to be open when flushing or
pressure testing the system. Strong pressure impacts can
damage closed valves.
Differential pressure across the valve’s control path is not
allowed to exceed 400 kPa.
4.8.2 - 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.
4.8.3. 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, WTC & NTC).
4.8.4 - Actuator replacement procedure
The actuators on both the chilled water and the hot water
valves may be replaced in case of failure.
WARNING : Do not connect on the same neutral wire the
valve actuator 24 Vac and the controller.
• 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 fitted 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. Refitting is by the
reversal of the procedure described above.
WARNING: Ensure that the actuator is firmly screwed to
the valve body (maximum torque 15 N·m).
4.8.5 - 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 flexible
water pipes.
• Remove the valve actuators taking care to identify
the cooling and heating valves.
• Disconnect the flexible 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
flow control valve bodies. Depending how the unit is
configured, the four-way valve coupling may be fitted
with a heating/cooling changeover switch, if so do not
remove it.
• Fit the new valve body to the coil (fit new gaskets).
• Reconnect the flexible condensate drain pipe which
is held in place by a collar (the collar is not supplied
by Carrier).