47
SUPPLY AIR RESET CONFIGURATION
Supply air reset can be used to modify the current cooling sup-
ply air set point. Supply air reset is applicable to control types,
C.TYP = 1, 2, 3, and 4. The configurations for reset can be
found at the local display under Configuration
EDT.R. See
Table 34.
EDT Reset Configuration (RS.CF)
This configuration applies to several machine control types
(Configuration
UNIT
C.TYP = 1,2,3, and 4).
•0 = NO RESET
No supply air reset is in effect
• 1 = SPT RESET
Space temperature will be used as the reset control variable
along with both RTIO and LIMT in the calculation of the fi-
nal amount of reset to be applied (Inputs
RSET
SA.S.R).
• 2 = RAT RESET
Return-air temperature will be used as the reset control
variable along with both RTIO and LIMT in the calcula-
tion of the final amount of reset to be applied (Inputs
RSET
SA.S.R).
•3 = THIRD PARTY RESET
The reset value is determined by a 4 to 20 mA third party
input. An input of 4 mA would correspond to 0ºF reset. An
input of 20 mA would correspond to 20ºF reset. Configur-
ing the control for this option will cause RES.S to become
enabled automatically with the CEM board. To avoid
alarms, make sure the CEM board and third party input are
connected before enabling this option.
Reset Ratio (RTIO)
This configuration is used when RS.CF is set to 1 or 2. For ev-
ery degree that the controlling temperature (space/return) falls
below the occupied cooling set point (OCSP), the calculated
value of the supply air reset will rise by the number of degrees
as specified by this parameter.
Reset Limit (LIMT)
This configuration is used when RS.CF is set to 1 or 2. This
configuration places a clamp on the amount of supply air reset
that can be applied.
EDT 4-20 mA Reset Input (RES.S)
This configuration is automatically enabled when Configura-
tion
EDT.R
RS.CF is set to 3 (third party reset).
COOLING CONFIGURATION
Relevant configurations for mechanical cooling are located at
the local display under Configuration
COOL. See Table 35.
Enable Compressor A1 (A1.EN)
This configuration is used to disable the A1 compressor in case
of failure for size 30 to 100 units.
Enable Compressor A2 (A2.EN)
This configuration is used to disable the A2 compressor in case
of failure for size 50 to 100 units. It is always disabled for size
30 to 40 units.
Enable Compressor A3 (A3.EN)
This configuration is used to disable the A3 compressor in case
of failure for size 90 and 100 units. It is always disabled for
size 30 to 75 units.
Enable Compressor B1 (B1.EN)
This configuration is used to disable the B1 compressor in case
of failure for size 30 to 100 units.
Enable Compressor B2 (B2.EN)
This configuration is used to disable the B2 compressor in case
of failure for size 40 to 100 units. It is always disabled for size
30 and 35 units.
Enable Compressor B3 (B3.EN)
This configuration is used to disable the B3 compressor in case
of failure for size 90 and 100 units. It is always disabled for
size 30 to 75 units.
Table 33 — Setpoints
Table 34 — Supply Air Reset Configuration
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULT
OHSP Occupied Heat Setpoint 40 to 99 dF OHSP 68
OCSP Occupied Cool Setpoint 40 to 99 dF OCSP 75
UHSP Unoccupied Heat Setpoint 40 to 99 dF UHSP 55
UCSP Unoccupied Cool Setpoint 40 to 110 dF UCSP 90
GAP Heat-Cool Setpoint Gap 2 to 10 deltaF HCSP_GAP 5
V.C.ON VAV Occ. Cool On Delta 0 to 25 deltaF VAVOCON 3.5
V.C.OF VAV Occ. Cool Off Delta 1 to 25 deltaF VAVOCOFF 2
SASP Supply Air Setpoint 45 to 75 dF SASP 55
SA.HI Supply Air Setpoint Hi 45 to 75 dF SASP_HI 55
SA.LO Supply Air Setpoint Lo 45 to 75 dF SASP_LO 60
SA.HT Heating Supply Air Setpt 90 to 145 dF SASPHEAT 85
T.PRG Tempering Purge SASP –20 to 80 dF TEMPPURG 50
T.CL Tempering in Cool SASP 5 to 75 dF TEMPCOOL 5
T.V.OC Tempering Vent Occ SASP –20 to 80 dF TEMPVOCC 65
T.V.UN Tempering Vent Unocc. SASP –20 to 80 dF TEMPVUNC 50
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULT
EDT.R EVAP.DISCHRGE TEMP RESET
RS.CF EDT Reset Configuration 0 to 3 EDRSTCFG 2
RTIO Reset Ratio 0 to 10 RTIO 3
LIMT Reset Limit 0 to 20 deltaF LIMT 10
RES.S EDT 4-20 ma Reset Input Enable/Disable EDTRSENS Disable
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