Remote Control Switch Input; Hot Gas Bypass; Space Temperature Offset - Carrier WEATHERMASTER 48/50Z030-105 Operation And Service Manual

ITEM
TEST Test Display LEDs
METR Metric Display
LANG Language Selection
PAS.E Password Enable
PASS Service Password
Remote Control Switch Input —
input is located on the RCB board and connected to TB201
terminals 1 and 2. The switch can be used for several remote
control functions. See Table 68.
Table 68 — Remote Switch Configuration
ITEM EXPANSION
REMT Remote
Input State
RM.CF Remote Switch
Config
RMI.L RemSw
Off-Unoc-Strt-NoOv
Remote Input State (Inputs
the actual real time state of the remote input.
Remote Switch Config (Configuration
— This is the configuration that allows the user to assign dif-
ferent types of functionality to the remote discrete input.
• 0 — NO REMOTE SW — The remote switch will not be
used.
• 1 — OCC-UNOCC SW — The remote switch input will
control the occupancy state. When the remote switch
input is ON, the unit will forced into the occupied mode.
When the remote switch is OFF, the unit will be forced
into the unoccupied mode.
• 2 — STRT/STOP — The remote switch input will start
and stop the unit. When the unit is commanded to stop,
any timeguards in place on compressors will be honored
first. When the remote switch is ON, the unit will be
commanded to stop. When the remote switch is OFF the
unit will be enabled to operate.
• 3 — OVERRIDE SW — The remote switch can be used
to override any internal or external time schedule being
used by the control and force the unit into an occupied
mode when the remote input state is ON. When the
remote switch is ON, the unit will be forced into an occu-
pied state. When the remote switch is OFF, the unit will
use its internal or external time schedules.
Remote Switch Logic Configuration (Configuration
→
SW.LG RMI.L) — The control allows for the configuration
of a normally open/closed status of the remote input switch via
RMI.L. If this variable is configured OPEN, then when the
switch is open, the remote input switch perceives the logic state
as OFF. Correspondingly, if RMI.L is set to CLOSED, the re-
mote input switch will perceive a closed switch as meaning
OFF. See Table 69.
Hot gas bypass is an automatically
Hot Gas Bypass —
operating system used to limit evaporator suction pressure
REMOTE
SWITCH LOGIC SWITCH
CONFIGURATION STATUS
(RMI.L)
OPEN
OPEN
CLOSED
OPEN
CLOSED
CLOSED
Table 67 — Display Configuration
EXPANSION
ON/OFF
ON/OFF
0-1(multi-text strings)
ENABLE/DISABLE
0000-9999
The remote switch
CCN
RANGE UNITS
POINT
ON/OFF RMTIN
0 - 3 RMTINCFG
Open/Close RMTINLOG
→ →
GEN.I REMT) — This is
→ →
UNIT RM.CF)
Table 69 — Remote Switch Logic Configuration
REMOTE INPUT STATE
(REMT)
OFF (0)
ON (1)
ON (0)
OFF (1)
RANGE UNITS
during periods of low evaporator loading. This system is not
controlled by the ComfortLink™ control system and it is
available to operate whenever circuit A is running.
The hot gas bypass option consists of a pressure regulating
valve, a manual service valve and tubing connecting the circuit
A hot gas refrigerant line to the circuit A evaporator distribu-
tors (one distributor on sizes 030-035, two distributors on sizes
040-105). The pressure regulating valve opens the bypass
circuit as the evaporator suction pressure decreases into a range
that might generate frost formation on the evaporator surface
if sustained compressor operation occurs. The hot gas refriger-
ant enters the evaporator coil and adds refrigeration load to the
compressor circuit to offset a low load situation in the mixed
air temperature condition. Total bypass capacity is approxi-
mately 5 tons.
The hot gas bypass system is a factory-installed option,
installed on circuit A only. When this option is provided, the
control function for Lead-Lag sequencing must be disabled
→
(Configuration
Space Temperature Offset —
set corresponds to a slider on a T56 sensor that allows the occu-
pant to adjust the space temperature by a configured range
during an occupied period. This sensor is only applicable to
units that are configured as either 2-Stage SPT or Multi-Stage
SPT control (Configuration
ITEM EXPANSION
SP.O.S Space Temp
Offset Sensor
SP.O.R Space Temp
Offset Range
SPTO Space Temperature
Offset
Space Temperature Offset Sensor (Configuration
→ →
SENS SP.O.S) — This configuration disables the reading
of the offset slider.
Space Temperature
→ →
UNIT SENS
→
the range, in degrees F, that the T56 slider can affect SPTO
when adjusting the slider from the far left (-SP.O.R) to the far
right (+SP.O.R). The default is 5° F.
Space Temperature Offset Value (Temperatures
→
SPTO) — The Space Temperature Offset Value is the read-
ing of the slider potentiometer in the T56 that is resolved to
delta degrees based on SP.O.R.
REMOTE SWITCH CONFIGURATION (RM.CF)
0
No Remote Switch Occ-Unocc Switch
xxxxx
xxxxx
xxxxx
xxxxx
83
POINT
TEST Off
DISPUNIT Off
LANGUAGE 0
PASS_EBL Enable
PASSWORD 1111
→
Cool L.L.EN is set to No).
Space Temperature Off-
→ →
UNIT C.TYP = 5 and 6).
RANGE UNITS
Enable/
Disable
1 - 10
+- SP.O.R ^F
Offset Range
→
SP.O.R) — This configuration establishes
1 2
Start/Stop
Unoccupied Start
Occupied Stop
Occupied Stop
Unoccupied Start
DEFAULT
CCN
POINT
SPTOSENS
SPTO_RNG
SPTO
→
UNIT
(Configuration
→
AIR.T
3
Override
No Override
Override
Override
No Override