30
Unit Configuration Submenu —
The
UNIT
sub-
menu under the Configuration mode of the local display
contains general unit configuration items. The sub-menu which
contains these configurations is located at the local display un-
der
Configuration
UNIT
.
See Table 32.
Machine Control Type (
C.TYP
) — This configuration de-
fines the control type and control source responsible for select-
ing a cooling, heating, or vent mode and determines the meth-
od by which compressors are staged. The control types are:
•
C.TYP
= 1 (VAV-RAT) and
C.TYP
= 2 (VAV-SPT)
Both of these configurations refer to standard VAV opera-
tion. If the control is occupied, the supply fan is run
continuously and return-air temperature will be used in the
determination of the selection of a cooling mode. VAV-SPT
differs from VAV-RAT only in that during the unoccupied
period, space temperature will be used instead of return-air
temperature to start the fan for 10 minutes to establish an
accurate return-air temperature before the return-air
temperature is allowed to call out any mode.
•
C.TYP
= 3 (TSTAT-MULTI)
This configuration will force the control to monitor the ther-
mostat inputs to make a determination of mode. Unlike
traditional 2-stage thermostat control, the unit is allowed to
use multiple stages of cooling control and perform VAV-
type operation. The control will be able to call out a LOW
COOL or a HIGH COOL mode and maintain a low or high
cool supply air setpoint.
•
C.TYP
= 4 (TSTAT-2 STG)
This configuration will force the control to monitor the ther-
mostat inputs to make a determination of mode and allow
only 2 stages of control for both heating and cooling.
•
C.TYP
= 5 (SPT-MULTI)
This configuration will force the control to monitor a space
temperature sensor to make a determination of mode.
Unlike traditional 2-stage space temperature control, the
unit is allowed to use multiple stages of cooling control and
perform VAV-type operation. The control will be able to call
out a LOW COOL or a HIGH COOL mode and maintain a
low or high cool supply air setpoint.
•
C.TYP
= 6 (SPT-2 STG)
This configuration will force the control to monitor the
space temperature sensor to make a determination of mode
and allow 2 stages of control for both heating and cooling.
Fan Mode (
CV.FN
) — The Fan Mode configuration can be
used for machine control types (
Configuration
UNIT
C.TYP
) 3, 4, 5, and 6. The Fan Mode variable establishes the
operating sequence for the supply fan during occupied periods.
When set to 1 (Continuous), the fan will operate continuously
during occupied periods. When set to 0 (Automatic), the fan
will run only during a heating or cooling mode.
Remote Switch Config (
RM.CF
) — The remote switch input
is connected to TB6 terminals 1 and 3. This switch can be used
for several remote control functions. Please refer to the Remote
Control Switch Input section on page 76 for details on its use
and operation.
CEM Model Installed (
CEM
) — This configuration instructs
the control to communicate with the controls expansion module
(CEM) over the Local Equipment Network (LEN) when set to
Yes. When the unit is configured for certain sensors and configu-
rations, this option will be set to Yes automatically.
The sensors and configurations that automatically turn on
this board are:
Configuration
UNIT
SFS.M
= 1 (Supply Fan Status
Switch Monitoring)
Configuration
EDT.R
RES.S
= Enable (4 to 20 mA Sup-
ply Air Reset Sensor Enable)
Configuration
DMD.L
DM.L.S
= 1 (2 SWITCHES)
(Demand Limiting using 2 discrete switches)
Configuration
DMD.L
DM.L.S
= 2 (4-20 MA CTRL)
(Demand Limiting using a 4 to 20 mA sensor)
Configuration
IAQ
AQ.CF
IQ.I.C
= 1 (IAQ DISCRETE)
(IAQ discrete switch control)
Configuration
IAQ
AQ.CF
IQ.I.C
= 2 (IAQ DISC.OVR)
(IAQ discrete switch “override” control)
Configuration
IAQ
AQ.CF
OQ.A.C
= 1 (OAQ SENS-
DAQ) (Outdoor Air Quality Sensor)
Configuration
IAQ
AQ.CF
OQ.A.C
= 2 (4-20 NO
DAQ) (4 to 20 mA sensor, no DAQ)
Temperature Compensated Start Cooling Factor (
TCS.C
) —
This factor is used in the equation of the Temperature Compen-
sated Start Time Bias for cooling. Refer to the Temperature
Compensated Start section on page 72 for more information. A
setting of 0 minutes indicates Temperature Compensated Start
in Cooling is not permitted.
Temperature Compensated Start Heating Factor
(
TCS.H
) —
This factor is used in the equation of the Temperature Compen-
sated Start Time Bias for heating. Refer to the Temperature
Compensated Start section for more information. A setting of
0 minutes indicates Temperature Compensated Start in Heating
is not permitted.
Fan Fail Shuts Downs Unit (
SFS.S
) — This configuration
will determine whether the unit should shut down on a supply
fan status fail or simply alert the condition and continue to run.
If set to YES, then the control will shut down the unit and send
out an alarm if supply fan status monitoring fails. If set to NO,
the control will not shut down the unit if supply fan status mon-
itoring fails but the control will send out an alert.
Fan Status Monitoring (
SFS.M
) — This configuration selects
the type of fan status monitoring to be performed.
0 - NONE — No switch or monitoring
1 - SWITCH — Use of the fan status switch
2 - SP RISE — Monitoring of the supply duct pressure
VAV Unoccupied Fan Retry Time (
VAV.S
) — Machine con-
trol types 1 and 2 (VAV-RAT,VAV-SPT) monitor the return-air
temperature during unoccupied periods to determine if there is
a valid demand for heating or cooling before initiating an unoc-
cupied heating or cooling mode. If the routine runs but con-
cludes a valid demand condition does not exist, then the pro-
cess is not permitted for the period of time defined by this con-
figuration. Reducing this value allows a more frequent re-
sampling process. Setting this value to zero will prevent any
sampling sequence.
Unit Size (
SIZE
) — There are several unit sizes (tons) for the
A Series control. Make sure this configuration matches the size
called out by the model number of the unit. This is important as
the cooling stage tables are directly determined based on this
configuration.
Discharge Pressure Transducers (
DP.XR
) — This configura-
tion configures the unit for use with discharge pressure trans-
ducers. The 48/50A units will be automatically configured for
discharge pressure transducers and
DP.XR
should be set to Yes.
Suction Pressure Transducer Type (
SP.XR
) — This configu-
ration specifies the type of suction pressure transducer that is
being used. Set
SP.XR
to 0 for support of a pressure transducer
with a range of 0 to 135 psig. Set
SP.XR
to 1 for support of a
pressure transducer with a range of 0 to 200 psig.
NOTE: The 48/50A units do not require a change to the
SP.XR
factory default setting.
Refrigerant Type (
RFG.T
) — This configuration specifies the
type of refrigerant used in the unit. Configuration
RFG.T
is set
to 0 if the refrigerant used is R-22. Configuration
RFG.T
is set
to 1 if the refrigerant used is R-410A. Do not change this
setting.
Summary of Contents for Carrier Weathermaker 48A2
Page 105: ...105 Fig 20 Typical Main Control Box Wiring Schematic 48 50A2 A3 A4 A5 Units...
Page 106: ...106 Fig 21 Typical Auxiliary Control Box Wiring Schematic...
Page 107: ...107 Fig 22 Typical 2 Stage Gas Heat Wiring Schematic Size 060 Units Shown a48 8357...
Page 108: ...108 TO NEXT PAGE Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown A48 7296...
Page 109: ...109 Fig 23 Typical Staged Gas Heat Wiring Schematic Size 060 Units Shown cont A48 8358...
Page 110: ...110 Fig 24 Typical Electric Heat Control Schematic 50 Series Size 060 Units Shown a50 8228...
Page 111: ...111 Fig 25 Typical Power Schematic 48 50A2 A3 A4 A5 060 Unit Shown...
Page 112: ...112 Fig 26 Typical Low Ambient Controls Option Wiring...
Page 113: ...113 Fig 27 Typical Small Chassis Component Location Size 020 035 Units...
Page 114: ...114 Fig 28 Typical Large Chassis Component Locations Size 040 060 Units...
Page 118: ...118 Fig 30 Economizer Control Board ECB1 and VAV Control Board ECB2 A48 7706...
Page 142: ...142 A48 3733 Fig 56 Main Burner Removal...
Page 176: ...176 APPENDIX C VFD INFORMATION cont Fig F Internal Enclosure Fan Replacement A48 7716...
