Carrier AquaForce 30XV140 Controls, Start-Up, Operation, Service And Troubleshooting Instructions page 37

4-20 mA TEMPERATURE RESET — The control system is
also capable of temperature reset based on an externally pow-
ered 4 to 20 mA signal. The Energy Management Module
(EMM) is required for temperature reset using a 4 to 20 mA
signal.
To use 4-20 mA Temperature Reset, four variables must be
configured: Cooling Reset Select, Current No Reset Value
(milliamp signal at which no temperature reset is required),
Current Full Reset Value (milliamp signal at which full tem-
perature reset is required), and Cooling Reset Deg Value (the
maximum amount of temperature reset desired).
CAUTION
Care should be taken when interfacing with other control
systems due to possible power supply differences such as a
full wave bridge versus a half wave rectification. Connec-
tion of control devices with different power supplies may
result in permanent damage. Touch Pilot controls incorpo-
rate power supplies with half wave rectification. A signal
isolation device should be utilized if the signal generator
incorporates a full wave bridge rectifier.
6
5
4
Cooling Reset
Deg. Value
(cr_deg)
3
2
1
0
0 2
Current No Reset Value
(v_hr_no)
4 6 8
mA Signal
Fig. 34 — Example: 4 to 20 mA Temperature Reset
To configure this option with the Touch Pilot™ display:
DISPLAY NAME
Cooling Reset
Select
0=None, 1=OAT
2=Delta T,
3=4-20mA control
4=Space Temp
Main Menu
Current No
Configuration Menu
Reset Value
Reset Configuration
Current Full
Reset Value
Cooling Reset
Deg Value
In the example in Fig. 34, at 4 mA no reset takes place and
at 20 mA, 5° F (2.8° C) chilled water set point reset is required.
Current Full Reset Value
10 12 14
37
PATH VALUE
Low = 0° F (0° C)
Default = 0° F (0° C)
High = 4 F (2.2 C)

Low = 0° F (0° C)

Default = 0° F (0° C))
High = 20 F (11.1 C)
Low = 0° F (0° C)
Default = 0° F (0° C)
High = 20 F (11.1 C)
Low = 30 F (16.7 C)
Default = 0° F (0° C)
High = 30 F (16.6 C)
(v_hr_fu)
16 18 20
a30-5885