Unit Configuration Submenu - Carrier 48AJ Operating And Service Manual

HVAC Mode — DEHUMIDIFICATION (23) — The unit is
operating in Dehumidification mode.
HVAC Mode — REHEAT (24) — The unit is operating in
reheat mode.
Unit Configuration Submenu —
menu under the Configuration mode of the local display
contains general unit configuration items. This section will
define all of these configurations here for easy reference. The
sub-menu which contains these configurations is located at the
local display under Configuration
Machine Control Type (C.TYP) — This configuration de-
fines the technique and control source responsible for selecting
a cooling, heating, or vent mode and in determining the method
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 temper-
ature 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 set point.
• 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 set point.
• 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
→
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 for details on its use and
operation.
The UNIT sub-
→
UNIT. See Table 43.
→
types (Configuration
CEM MODEL INSTALLED (CEM) — This configuration in-
structs 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 configurations, this option will be set to Yes automatically.
The sensors and configurations that automatically turn on
this board are:
→
Configuration UNIT
Switch Monitoring)
→
Configuration EDT.R
ply Air Reset Sensor Enable)
→
Configuration DMD.L
(Demand Limiting using 2 discrete switches)
→
Configuration DMD.L
(Demand Limiting using a 4 to 20 mA sensor)
→ →
Configuration IAQ
(IAQ discrete switch control)
→ →
Configuration IAQ
(IAQ discrete switch "override" control)
→ →
Configuration IAQ
DAQ) (Outdoor Air Quality Sensor)
→ →
Configuration IAQ
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 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) include a process for
sampling the return-air temperature during unoccupied periods
to prove a valid demand for heating or cooling before initiating
an unoccupied heating or cooling mode. If the sampling
routine runs but concludes a valid demand condition does not
exist, the sampling process will not be permitted for the period
of time defined by this configuration. 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.
35
→
SFS.M = 1 (Supply Fan Status
→
RES.S = Enable (4 to 20 mA Sup-
→
DM.L.S = 1 (2 SWITCHES)
→
DM.L.S = 2 (4-20 MA CTRL)
→
AQ.CF IQ.I.C = 1 (IAQ DISCRETE)
→
AQ.CF IQ.I.C = 2 (IAQ DISC.OVR)
→
AQ.CF OQ.A.C = 1 (OAQ SENS-
→
AQ.CF OQ.A.C = 2 (4-20 NO