Specifications

30
Table 31 — Unit Configuration
Discharge Pressure Transducers (
DP.XR) — This configuration
configures the unit for use with discharge pressure transducers.
MAT Calc Config (
MAT.S) — This configuration gives the
user two options in the processing of the mixed-air temperature
(MAT) calculation:
• MAT.S =0
The control will not attempt to learn MAT over time. The
control will simply calculate MAT based on the position of
the economizer, outside and return air temperature, linearly.
• MAT.S =1
The control will attempt to learn MAT over time. Any time
the system is in a vent mode and the economizer stays at a
particular position for long enough, MAT = EDT. Using
this, the control has an internal table whereby it can more
closely determine the true MAT value.
ResetMATTableEntries?(
MAT.R) — This configuration
allows the user to reset the internally stored MAT learned con-
figuration data back to the default values. The defaults are set
to a linear relationship between the economizer damper posi-
tion and OAT and RAT in the calculation of MAT.
Altitude……..In Feet: (
ALTI) — As the control does not in-
clude a barometric pressure sensor to define the calculation of
enthalpy and cfm, the control does include an altitude parame-
ter which will serve to set up a default barometric pressure for
use with calculations. The effect of barometric pressure in
these calculations is not great, but could have an effect depend-
ing on the installed elevation of the unit. If the rooftop is
installed at a particularly high altitude and enthalpy or cfm are
being calculated, set this configuration to the current elevation
of the installed rooftop.
Space Temp Sensor (
SPT.S) — If a space temperature sensor
is installed (T55/T56), enable this configuration.
Space Temp Offset Sensor (
SP.O.S) —IfaT56sensoris
installed with the space temperature offset slider, enable this
configuration.
Space Temp Offset Range (
SP.O.R) — If a space tempera-
ture offset sensor is installed, it is possible to configure the
range of the slider by adjusting this range configuration.
Return RH Sensor (
RRH.S) — If a return air relative humidi-
ty sensor is installed, enable this configuration.
Filter Status Switch Enabled? (
FLT.S) — If a filter status
switch is installed, enable this configuration to begin the moni-
toring of the filter status input (Inputs
→ GEN.I → FLT.S). See
the Dirty Filter Switch section for more details on installation
and operation.
Static Pressure Reset Sensor (
SP.RS) — If the outdoor air
quality sensor is not configured (Configuration → IAQ
→ AQ.CF → OQ.A.C =0), then it is possible to use the OAQ
sensor’s location on the CEM board to control and adjust the
set point remotely for the static pressure reset via an external
4 to 20 mA input. Enabling this sensor will give the user
the ability to reset the supply static pressure set point (Configu-
ration
→ SP → SP.SP) from 0 to 3 in. wg of static pressure
where 4 mA = 0 in. wg and 20 mA = 3 in. wg.
As an example: If the static pressure reset input is measur-
ing 6 mA, then the input is reset 2 mA of its 16 mA (4 to
20 mA) control range. This is 2/16 of 3 in. wg or 0.375 in. wg
of reset. If the static pressure set point (SP.SP) = 1.5 in. wg,
then the static pressure control point for the system will be
1.5 – 0.375 = 1.125 in. wg.
Cooling Control — When mechanical cooling is required,
the A Series ComfortLink™ control has the capability to con-
trol the staging of the compressors in several different ways.
Three scroll compressors are used on sizes 020 to 027 and four
on sizes 030 to 060. In addition, the ComfortLink control sup-
ports the use of an optional minimum load hot gas bypass
valve (MLV) that is directly controlled by the ComfortLink
control, and provides an additional stage of capacity as well as
low load coil freeze protection. The control also integrates the
use of an economizer with the use of mechanical cooling to
allow for the greatest use of free cooling. When both mechani-
cal cooling and the economizer are being used, the control will
use the economizer to provide better temperature control and
limit the cycling of the compressors. The control also checks
on various other operation parameters in the units to make sure
that safeties are not exceeded and the compressors are reliably
operated.
The A Series ComfortLink™ control offers two basic con-
trol approaches to mechanical cooling. Constant volume for 2
stages of cooling and VAV for multiple stages of cooling. In ad-
dition to these methods of control, the A Series ComfortLink
control offers the ability to run multiple stages of cooling for ei-
ther a space temperature sensor or thermostat by controlling the
unit to either a low or high cool supply air set point. The con-
trol type (Configuration
→ UNIT → C.TYP) determines the
selection of the type of cooling control as well as the technique
for selecting a cooling mode.
ITEM EXPANSION RANGE UNITS CCN POINT DEFAULTS
UNIT UNIT CONFIGURATION
C.TYP Machine Control Type 1 - 6 CTRLTYPE 4
CV. FN Fan Mode (0=Auto, 1=Cont) 0 - 1 FAN_MODE 1
RM.CF Remote Switch Config 0 - 3 RMTINCFG 0
CEM CEM Module Installed Yes/No CEM_BRD No
TCS.C Temp.Cmp.Strt.Cool Factr 0 - 60 min TCSTCOOL 0
TCS.H Temp.Cmp.Strt.Heat Factr 0 - 60 min TCSTHEAT 0
SFS.S Fan Fail Shuts Down Unit Yes/No SFS_SHUT No
SFS.M Fan Stat Monitoring Type 0 - 2 SFS_MON 0
VAV.S VAV Unocc.Fan Retry Time 0 - 720 min SAMPMINS 50
SIZE Unit Size (20-60) 20 - 60 UNITSIZE20
DP.XR Discharge Press. Transducers Yes/No DP_TRANS No
MAT.S MAT Calc Config 0 - 1 MAT_SEL 1
MAT.R Reset MAT Table Entries? Yes/No MATRESET No
ALTI Altitude……..in feet: 0 - 60000 ALTITUDE 0
SENS INPUT SENSOR CONFIG
SPT.S Space Temp Sensor Enable/Disable SPTSENS Disable
SP.O.S Space Temp Offset Sensor Enable/Disable SPTOSENS Disable
SP.O.R Space Temp Offset Range 1 - 10 SPTO_RNG 5
RRH.S Return Air RH Sensor Enable/Disable RARHSENS Disable
FLT.S Filter Stat.Sw.Enabled ? Enable/Disable FLTS_ENA Disable
SP.RS Stat. Pres. Reset Sensor Enable/Disable SPRSTSEN Disable