Specifications
37
To configure this option with the Navigator™ display:
In the space temperature reset example in Fig. 22, 0° F
(0° C) chilled water set point reset at 72 F (22.2 C) space
temperature and 6° F (3.3° C) reset at 68 F (20.0 C) space
temperature.
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 Type (Cooling Reset Select, CRST)
must be enabled. The milliamp signal at which no temperature
reset is required, Current No Reset Value (Current No Reset
Value, CRV1), must be set. The milliamp signal at which full
temperature reset is required, Current Full Reset Value (Cur-
rent Full Reset Value, CRV2), must be set. Finally, the
amount of temperature reset desired, Degrees Cool Reset
(Cooling Reset Deg. Value, DRGC), must be set.
To configure this option with the Touch Pilot™ display:
To configure this option with the Navigator™ display:
In the example in Fig. 23, at 4 mA no reset takes place and
at 20 mA, 5° F (2.8° C) chilled water set point reset is required.
ITEM ITEM EXPANSION PATH VALUE
CRST Cooling Reset Type Configuration RSET
Default =
No Reset
Space Temp
CRS1
Space T No Reset
Te mp
Setpoints COOL
Default =
14 F (–10 C)
CRS2
Space T Full Reset
Te mp
Setpoints COOL
Default =
14 F (–10 C)
DGRC Degrees Cool Reset Setpoints COOL
Default =
0 F (0 C)
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. The ComfortLink controls
incorporate power supplies with half wave rectification. A
signal isolation device should be utilized if the signal gen-
erator incorporates a full wave bridge rectifier.
DISPLAY NAME PATH LINE NO. VALUE
Cooling Reset
Select
Main Menu
Config USER
19
Default =0
(No Reset)
3 (4-20mA
Control)
Current No
Reset Value
Main Menu
Setpoint SETPOINT
9 Default = 0.0
Current Full
Reset Value
Main Menu
Setpoint SETPOINT
10 Default = 0.0
Cooling Reset
Deg. Value
Main Menu
Setpoint SETPOINT
13
Default =
0.0 F (0.0 C)
ITEM ITEM EXPANSION PATH VALUE
CRST
Cooling Reset
Ty p e
Configuration RSET
Default =
No Reset
4-20mA Input
CRV1
Current No
Reset Temp
Setpoints COOL Default = 0.0
CRV2
Current Full
Reset Temp
Setpoints COOL Default = 0.0
DGRC
Degrees Cool
Reset
Setpoints COOL Default = 0.0
Load%
Fluid Temperature (deg F)
EWT
LWT
40
42
44
46
48
50
52
54
56
1009080706050403020100
Design
Rise
(typical)
Fig. 19 — Leaving Chilled Water Temperature Control
a30-4066