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42
DELTA T RESET (RETURN WATER RESET)
The control system is also capable of performing fluid tem-
perature reset based on evaporator fluid temperature difference
(Delta T), sometimes called return water reset. Because the
change in temperature through the evaporator is a measure of
the building load, the temperature difference reset is, in effect,
an average building load reset method.
Delta T Reset allows for the chilled water temperature set point
to be reset upward as a function of the fluid temperature differ-
ence (building load).
NOTE: Delta T (Return Water) Temperature Reset should not
be used with variable evaporator flow rate systems.
To use Delta T Reset, four variables must be configured: Cool-
ing Reset Select, Delta T No Reset Value (evaporator tempera-
ture difference at which no chilled water temperature reset
should occur), Delta T Full Reset Value (evaporator tempera-
ture difference at which the maximum chilled water tempera-
ture reset should occur), and Cooling Reset Deg Value (the
maximum amount of temperature reset desired).
To configure this option with the Carrier Controller display:
In the example in Fig. 40 using Return Water Temperature Re-
set, the chilled water temperature will be reset by 5°F (2.8°C)
when the Fluid Temperature Difference is 2°F (1.1°C) and 0°F
(0°C) reset when the Temperature Difference is 10°F (5.6°C).
Fig. 40 — Example: Return Water Reset
DISPLAY
NAME
PATH
VALUE
Cooling Reset
Select
Main Menu
Configuration Menu
Reset Configuration
Default = 2
0=None,
1=OAT
2=Delta T,
3=4 to 20mA control
4=Space Temp
Delta T No
Reset Temp
Default = 0°F (0°C)
Range 0°F to 25°F
(0°C to 13.8°C)
Delta T Full
Reset Temp
Default = 0°F (0°C)
Range 0°F to 25°F
(0°C to 13.8°C)
Cooling Reset
Deg Value
Default = 0°F (0°C)
Range –30 to 30°F
(–16.7 to 16.6°C)
0
1
2
3
4
5
6
0
ENTERING-LEAVING WATER TEMPERATURE (de
g
F)
DEGREE
S
RE
S
ET (de
g
F)
Cooling
Re
s
et
Deg. V
a
l
u
e
(cr_deg)
Delt
a
T No Re
s
et Temp
(dt_hr_no)
Delt
a
T F
u
ll Re
s
et Temp
(dt_hr_f
u
)
2 4 6
8
10
a30-5886
Summary of Contents for AquaForce 30XV140
Page 79: ...79 Fig 76 VFD Communication Wiring Compressor A B Fan VFD A1 A2 B1 B2...
Page 228: ...228 Fig 90 30XV Typical Field Wiring Schematic cont...
Page 229: ...229 Fig 91 30XV Standard Tier 140 275 All Voltages Power Schematic NOTE See Legend on page 226...
Page 230: ...230 Fig 92 30XV Standard Tier 300 325 All Voltages Power Schematic NOTE See Legend on page 226...
Page 240: ...240 Fig 99 30XV Communication Wiring...
Page 241: ...241 Fig 100 30XV 115V Control Wiring All Tonnages All Voltages...
Page 242: ...242 Fig 101 30XV 24V Control Wiring 30XV140 325 All Voltages...
Page 243: ...243 Fig 101 30XV 24V Control Wiring 30XV140 325 All Voltages cont...
Page 244: ...244 Fig 102 30XV 24V Control Wiring 30XV350 500 All Voltages...
Page 245: ...245 Fig 102 30XV 24V Control Wiring 30XV350 500 All Voltages cont...
Page 246: ...246 Fig 103 Component Arrangement Diagram for 30XV140 325...
Page 247: ...247 Fig 103 Component Arrangement Diagram for 30XV140 325 cont...
Page 248: ...248 Fig 104 Component Arrangement Diagram for 30XV350 500...
Page 337: ...337 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig L System Information...
Page 338: ...338 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig M Unit and Language Settings...
Page 341: ...341 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig P Data Input 2...
Page 342: ...342 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig Q Data Input 3...
Page 347: ...347 APPENDIX J FACTORY SUPPLIED PUMPS cont Fig U Pump Wiring Diagram...