Hot Gas Bypass; Space Temperature Offset; Time Clock Configuration - United Technologies Carrier Weathermaker 48A2 Controls, Start-Up, Operation, Service, And Troubleshooting

REMOTE
SWITCH LOGIC SWITCH
CONFIGURATION STATUS
(RMI.L)
OPEN
OPEN
CLOSED
OPEN
CLOSED
CLOSED
Hot gas bypass is an active part of
Hot Gas Bypass —
the A Series ComfortLink capacity staging and minimum
evaporator load protection functions. It is controlled though the
Minimum Load Valve function.
The hot gas bypass option consists of a solenoid valve with
a fixed orifice sized to provide a nominal 3-ton evaporator load
bypass. A hot gas refrigerant line routes the bypassed hot gas
from Circuit A's discharge line to Circuit A's evaporator
distributor. When the unit control calls for hot gas bypass, the
hot gas enters the evaporator coil and adds refrigeration load
to the compressor circuit to reduce the cooling effect from
Circuit A.
The hot gas bypass system is a factory-installed option
installed on Circuit A only. This function is enabled at Config-
 
uration COOL MLV. When this function is enabled, an
additional stage of cooling capacity is provided by the unit
control staging sequences (see Tables 38, 39, 43, and 45).
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 Offset
  
UNIT SENS SP.O.R) — This configuration establishes
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.

TIME CLOCK CONFIGURATION

This section describes each Time Clock menu item. Not
every point will need to be configured for every unit. Refer to
the Controls Quick Start section for more information on what
setpoints need to be configured for different applications. The
Time Clock menu items are discussed in the same order that
they are displayed in the Time Clock table. The Time Clock
table is shown in Table 78.
Hour and Minute (HH.MM) —
of the time clock are displayed in 24-hour, military time. Time
can be adjusted manually by the user. When connected to the
CCN, the unit can be configured to transmit time over the
Table 77 — Remote Switch Logic Configuration
REMOTE INPUT STATE
(REMT)
OFF
ON
ON
OFF
Space temperature off-

UNIT C.TYP = 5 or 6).
CCN
RANGE UNITS
POINT
Enable/ SPTOSENS
Disable
1 - 10 SPTO_RNG
+- SP.O.R ^F SPTO

UNIT
Range (Configuration

AIR.T
The hour and minute
REMOTE SWITCH CONFIGURATION (RM.CF)
0
No Remote Switch Occ-Unocc Switch
xxxxx Unoccupied
xxxxx Occupied
xxxxx Occupied
xxxxx Unoccupied
network or receive time from a network device. All devices on
the CCN should use the same time. Only one device on the
CCN should broadcast time or problems will occur.
Month of Year (MNTH) —
month of the calendar year.
Day of Month (DOM) —
day (1 to 31) of the month.
Day of Week (DAY) —
of the week (Monday = 1 through Sunday = 7).
Year (YEAR) —
ample, 2005).
Local Time Schedule (SCH.L) —
used to program the time schedules. There are 8 periods
(PER.1 through PER.8). Each time period can be used to set
up a local schedule for the unit.
Monday In Period (PER.X
able is used to include or remove Monday from the schedule.
Each period is assigned an occupied on and off time. If this
variable is set to YES, then Monday will be included in that peri-
od's occupied time schedule. If this variable is set to NO, then
the period's occupied time schedule will not be used on Monday.
This variable can be set for Periods 1 through 8.
Tuesday In Period (PER.X
is used to include or remove Tuesday from the schedule. Each
period is assigned an occupied on and off time. If this variable
is set to YES, then Tuesday will be included in that period's oc-
cupied time schedule. If this variable is set to NO, then the peri-
od's occupied time schedule will not be used on Tuesday. This
variable can be set for Periods 1 through 8.
Wednesday In Period (PER.X
variable is used to include or remove Wednesday from the
schedule. Each period is assigned an occupied on and off time.
If this variable is set to YES, then Wednesday will be included
in that period's occupied time schedule. If this variable is set to
NO, then the period's occupied time schedule will not be used
on Wednesday. This variable can be set for Periods 1 through 8.
Thursday In Period (PER.X
able is used to include or remove Thursday from the schedule.
Each period is assigned an occupied on and off time. If this
variable is set to YES, then Thursday will be included in that
period's occupied time schedule. If this variable is set to NO,
then the period's occupied time schedule will not be used on
Thursday. This variable can be set for Periods 1 through 8.
Friday In Period (PER.X
used to include or remove Friday from the schedule. Each peri-
od is assigned an occupied on and off time. If this variable is set
to YES, then Friday will be included in that period's occupied
time schedule. If this variable is set to NO, then the period's oc-
cupied time schedule will not be used on Friday. This variable
can be set for Periods 1 through 8.
Saturday In Period (PER.X
able is used to include or remove Saturday from the schedule.
Each period is assigned an occupied on and off time. If this
variable is set to YES, then Saturday will be included in that
period's occupied time schedule. If this variable is set to NO,
77
1 2
Start/Stop
Start No Override
Stop
Stop
Start No Override
This variable is the current
This variable is the current
This variable is the current day
This variable is the current year (for ex-
This submenu is
 
DAYS MON) — This vari-
 
DAYS TUE) — This variable
 
DAYS WED) — This
 
DAYS THU) — This vari-
 
DAYS FRI) — This variable is
 
DAYS SAT) — This vari-
3
Override
Override
Override