Specifications

23
Table 15 — Configuring Outdoor Air and Space Temperature Reset
*1 item skipped in this example.
Table 16 — Configuring Return Temperature Reset
*1 item skipped in this example.
Under normal operation, the chiller will maintain a constant
leaving fluid temperature approximately equal to the chilled
fluid set point. As the cooler load varies, the entering cooler
fluid will change in proportion to the load as shown in Fig. 17.
Usually the chiller size and leaving-fluid temperature set point
are selected based on a full-load condition. At part load, the flu-
id temperature set point may be colder than required. If the
leaving fluid temperature was allowed to increase at part load,
the efficiency of the machine would increase.
Return temperature reset allows for the leaving temperature
set point to be reset upward as a function of the return fluid
temperature or, in effect, the building load.
Demand Limit — Demand limit is a feature that allows
the unit capacity to be limited during periods of peak energy us-
age. There are 3 types of demand limiting that can be config-
ured. The first type is through 2-stage switch control, which will
reduce the maximum capacity to 2 user-configurable percentag-
es. The second type is by 4 to 20 mA signal input which will re-
duce the maximum capacity linearly between 100% at a 4 mA
input signal (no reduction) down to the user-configurable level
at a 20 mA input signal. The third type uses the CCN Loadshed
module and has the ability to limit the current operating capaci-
ty to maximum and further reduce the capacity if required.
NOTE: The 2-stage switch control and 4 to 20-mA input sig-
nal types of demand limiting require the energy management
module (EMM).
MODE
(RED LED)
KEYPAD
ENTRY
SUB-
MODE
KEYPAD
ENTRY
ITEM
DISPLAY
ITEM
EXPANSION
COMMENT
Outdoor
Air
Space
CONFIGURATION
DISP
UNIT
OPT1
OPT2
CCN
RSET CRST 2 4
COOLING RESET
TYPE
2 = Outdoor-Air Temperature
(Connect to LVT-4,5)
4 = Space Temperature
(Connect to LVT-3,4)
RM.NO* 85 °F 72 °F
REMOTE - NO
RESET TEMP
Default: 125.0 F (51.7 C)
Range: 0° to125 F
(–17.8 to 51.7 C)
RM.F 55 °F 68 °F
REMOTE - FULL
RESET TEMP
Default: 0.0° F (-17.7 C)
Range: 0° to 125 F
(–17.8 to 51.7 C)
RM.DG 15 F6 F
REMOTE - DEGREES
RESET
Default: 0° F (0° C)
Range: –30 to 30 F
(–16.7 to -16.7 C)
MODE
(RED LED)
KEYPAD
ENTRY
SUB-MODE
KEYPAD
ENTRY
ITEM DISPLAY
ITEM
EXPANSION
COMMENT
CONFIGURATION
DISP TEST ON/OFF TEST DISPLAY LEDs
UNIT TYPE X UNIT TYPE
OPT1 FLUD X COOLER FLUID
OPT2 CTRL X CONTROL METHOD
CCN
RSET CRST 3 COOLING RESET TYPE
0 = No Reset
1 = 4 to 20 mA Input (EMM required)
(Connect to EMM TB6-2,3)
2 = Outdoor-Air Temperature
3 = Return Fluid
4 = Space Temperature
(Connect to TB5-5,6)
RT.NO* 10.0 F
RETURN FLUID - NO
RESET TEMP
Default: 10.0 F (5.6 C)
Range: 0° to 30 F COOLER DT
(0.0 to 16.7 C)
RT.F 2.0 F
RETURN FLUID - FULL
RESET TEMP
Default: 0 F (–17.8 C)
Range: 0° to 30 F COOLER DT
(0.0 to 16.7 C)
RT.DG 5.0 F
RETURN - DEGREES
RESET
Default: 0 
F (0 C)
Range: –30 to 30°F (–16.7 to 16.7 C)
ENTER
ENTER
ENTER
ENTER
ENTER
ENTER
ENTER
ENTER