Trane CVHE

CVHE-SB-32A 111
Outdoor
CWS' = CWS + RATIO * (START RESET - TOD)
and CWS' > or = CWS
and CWS' - CWS < or = Maximum Reset
where
CWS' is the new chilled water setpoint,
CWS is the active chilled water setpoint before any reset has occurred
RESET RATIO is a user adjustable gain
START RESET is a user adjustable reference
TOD is the outdoor temperature
TWE is entering evap. water temperature
TWL is leaving evap. water temperature
MAXIMUM RESET is a user adjustable limit providing the maximum amount of reset. For all
types of reset, CWS' - CWS < or = Maximum Reset.
The values for “RESET RATIO” for each of the reset types are:
The values for “START RESET” for each of the reset types are:
Reset Type
Reset Ratio
Range
Increment
(English Units)
Increment (SI
Units)
Factory Default
Value
Return:
10 to 120% 1% 1% 50%
Outdoor
80 to -80% 1% 1% 10%
Reset Type
Start Reset
Range
Increment
(English Units)
Increment (SI
Units)
Factory Default
Value
Return
4 to 30°F 1°F 0.1°C 10°F (5.6°C)
(2.2 to 16.7°C)
Outdoor
50 to 130°F 1°F 0.1°C 90°F (32.2°C)
(10 to 54.4°C)