Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 46

ITEM
EDT.R EVAP.DISCHRGE TEMP RESET
RS.CF EDT Reset Configuration
RTIO Reset Ratio
LIMT Reset Limit
RES.S EDT 4-20 ma Reset Input
Lead/Lag Operation? (LLAG)
This configuration selects the type of lead/lag compressor op-
eration for the unit. There are 3 choices: automatic, Circuit A,
and Circuit B.
0 = AUTOMATIC
If this configuration is set to "AUTOMATIC," every time cool-
ing capacity drops to 0%, on the next call for cooling, the con-
trol will start up the first compressor on the circuit that did not
start on the previous cooling cycle.
1 = CIRCUIT A
If this configuration is set to "CIRCUIT A," every time cooling
capacity drops to 0%, a Circuit A compressor is always the
first to start on the next call for cooling.
2 = CIRCUIT B
If this configuration is set to "CIRCUIT B," every time cooling
capacity drops to 0%, a Circuit B compressor is always the first
to start on the next call for cooling.
NOTE: If the unit is configured for a Digital Scroll (Configu-
ration  DG.A1 = YES) or Minimum Load Valve (Configura-
tion  MLV = ENABLE), then Circuit A is always the lead cir-
cuit regardless of the setting of this configuration.
If the unit is configured for the Humidi-MiZer
midification system, then Circuit B automatically becomes the
lead circuit when the unit enters into one of the Humidi-MiZer
modes (dehumidification or reheat). The unit will immediately
start a Circuit B compressor when a Humidi-MiZer mode is
initiated.
High Capacity Evaporator (HC.EV)
This configuration is selects the type of evaporator coil in-
stalled at the factory on the unit. Yes = High capacity. No =
Standard capacity. This configuration is set at the factory and
should never need to be changed in the field.
High Efficiency Outdoor Fans (H.ODF)
This configuration selects the type of condenser coil and out-
door fans installed at the factory on the unit. Yes = High effi-
ciency. No = Standard efficiency. This configuration is set at
the factory and should never need to be changed in the field.
MotorMaster Control? (M.M.)
The condenser fan staging control for the unit is managed di-
rectly by the ComfortLink controls. There is no physical Motor-
master device in the standard unit. If the unit was ordered from
the factory with low ambient control (Motormaster) option,
nothing further needs to be done. This configuration must be
set to YES if an accessory low ambient operation Motormas-
ter V control is installed on the unit. Setting this configuration
®
to YES alters the condenser fan staging sequence to accommo-
date the Motormaster V control. See Head Pressure Control
section, page 55, for more information.
MotorMaster Setpoint Offset (MM.OF)
This configuration is the offset from Maximum Condensing
Temperature (SCT.H) and determines the MotorMaster head
pressure control point. MotorMaster Setpoint (MM.SP) =
SCT.H + MM.OF. The MotorMaster Setpoint is not directly set-
table and can only be set via the MotorMaster Setpoint Offset.
Table 27 — Supply Air Reset Configuration
EXPANSION
adaptive dehu-
®
RANGE UNITS
0 to 3
0 to 10
0 to 20 deltaF
Disable/Enable
MotorMaster PID Configuration (M.PID)
The configurations in this subset are the PID control parame-
ters for the MotorMaster control. These configurations should
not be adjusted in the field.
Maximum Condenser Temp (SCT.H)
This configuration defines the saturated condensing tempera-
ture at which the head pressure control routine will increase an
outdoor fan stage. The saturated condensing temperature of ei-
ther running circuit rising above this temperature will increase
a fan stage. If the outdoor-air temperature is greater than 72°F,
then no outdoor fan staging will occur, and the outdoor fan
stage will default to the maximum stage.
Minimum Condenser Temp (SCT.L)
This configuration defines the saturated condensing tempera-
ture at which the head pressure control routine will decrease an
outdoor fan stage. The saturated condensing temperature of
both running circuits decreasing below this temperature will
decrease a fan stage. If the outdoor-air temperature is greater
than 72°F no outdoor fan staging will occur, and the outdoor
fan stage will default to the maximum stage.
A1 is Digital Scroll (DG.A1)
This configuration instructs the unit controls as to whether the
A1 compressor is a digital scroll or regular scroll compressor.
If set to YES, the compressor will be controlled by the com-
pressor staging routine and SUMZ Cooling Algorithm.
A1 Min Digital Capacity (MC.A1)
This configuration defines the minimum capacity the digital scroll
compressor is allowed to modulate to. The digital scroll compres-
sor modulation range will be limited from MC.A1 to 100%.
Dig Scroll Adjust Delta (DS.AP)
This configuration defines the maximum capacity the digital
scroll will be allowed to change per request by the SUMZ
Cooling Algorithm.
Dig Scroll Adjust Delay (DS.AD)
This configuration defines the time delay in seconds between
digital scroll capacity adjustments.
Dig Scroll Reduce Delta (DS.RP)
This configuration defines the maximum capacity the digital
scroll will be allowed to decrease per request by the SUMZ
Cooling Algorithm when OAT is greater than Configura-
tion  M.PID  DS.RO. This ramped reduction is only im-
posed on a decrease in digital scroll capacity. An increase in
capacity will continue to follow the value defined by Configu-
ration  M.PID  DS.AP.
Dig Scroll Reduce Delay (DS.RD)
This configuration defines the time delay, in seconds, between
digital scroll capacity reduction adjustments when OAT is
greater than Configuration  DS.RO. This ramped reduction is
only imposed on a decrease in digital scroll capacity. An in-
crease in capacity will continue to follow the value defined by
Configuration  DS.AD.
Dig Scroll Reduction OAT (DS.RO)
Under certain operating conditions, a sharp decrease in digital
scroll capacity can result in unstable unit operation. This con-
figuration defines the outdoor air temperature above which a
reduced capacity (Configuration  DS.RP) and time delay
(Configuration  DS.RD) will be imposed on a digital scroll
46
CCN POINT DEFAULT
EDRSTCFG 2
RTIO 3
LIMT 10
EDTRSENS Disable