46
Table 27 —
Supply Air Reset Configuration
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
®
adaptive dehu
-
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
Comfort
Link 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.
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
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
Disable/Enable
EDTRSENS
Disable
Summary of Contents for WeatherExpert 48N2
Page 135: ...135 Fig 18 48 50N Typical Power Schematic Nominal 075 Ton Unit Shown ...
Page 136: ...136 Fig 19 48 50N Typical Power Schematic Nominal Ton 90 150 Units Shown ...
Page 137: ...137 Fig 20 48 50N Main Base Board Input Output Connections ...
Page 138: ...138 Fig 21 48 50N RXB EXB CEM Input Output Connections a48 9307 ...
Page 139: ...139 Fig 22 48 50N EXV SCB Input Output Connections a48 9308 ...
Page 140: ...140 Fig 23 48N Typical Modulating Gas Heat Unit Control Wiring ...
Page 141: ...141 Fig 24 50N Typical Electric Heat Unit Control Wiring ...
Page 144: ...144 Fig 27 48N Typical Gas Heat Section Wiring Nominal Ton 120 to 150 Units ...
Page 145: ...145 Fig 28 48 50N Typical Power Component Control Wiring 460 v ...
Page 146: ...146 Fig 29 48 50N Component Control Wiring 575 v Nominal Ton 075 to 150 Units ...
Page 147: ...147 Fig 30 48 50N Component Arrangement Power Box ...
Page 148: ...148 Fig 31 48 50N Component Arrangement Control Box ...
Page 240: ...240 APPENDIX D VFD INFORMATION CONT Fig G VFD Bypass Wiring Diagram WHEN USED ...