Hot Gas Bypass; Space Temperature Offset; Time Clock Configuration - Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service And Troubleshooting Instructions

REMOTE
SWITCH LOGIC SWITCH
CONFIGURATION STATUS
(RMI.L)
OPEN
OPEN
CLOSED
OPEN
CLOSED
CLOSED
The ComfortLink control system
Hot Gas Bypass —
supports the use of an optional minimum load hot gas bypass
valve (MLV) that is directly controlled by the ComfortLink
control system. This provides an additional stage of capacity as
well as low load coil freeze protection. Hot gas bypass is an
active part of the N-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 re-
frigerant line routes the bypassed hot gas from the discharge
line of circuit A to the suction line of circuit A. An additional
thermistor in the suction line allows the unit control to monitor
suction superheat. When the unit control calls for hot gas by-
pass, the hot gas bypasses the evaporator 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 in-
stalled on Circuit A only. This function is enabled at Configu-
 
ration COOL MLV. When this function is enabled, an ad-
ditional stage of cooling capacity is provided by the unit con-
trol staging sequences (see Appendix C).
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 Multi-Stage SPT control (Configu-
 
ration UNIT C.TYP = 4).
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
set points need to be configured for different applications. The
Table 70 — Remote Switch Logic Configuration
REMOTE INPUT STATE
(REMT)
OFF (0)
ON (1)
ON (0)
OFF (1)
Space Temperature Off-
CCN
RANGE UNITS
POINT
Enable/ SPTOSENS
Disable
1 - 10 SPTO_RNG
+- SP.O.R ^F SPTO

UNIT
Range (Configuration

AIR.T
REMOTE SWITCH CONFIGURATION (RM.CF)
0
No Remote Switch Occ-Unocc Switch
xxxxx Unoccupied
xxxxx Occupied
xxxxx Occupied
xxxxx Unoccupied
Time Clock menu items are discussed in the same order that
they are displayed in the Time Clock table. The Time Clock
menu is shown in Table 71.
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 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 through Sunday).
Year (YEAR) —
ample, 2013).
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. Refer to the Programming
Operating Schedules section on page 29 for more information.
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
able 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 pe-
riod's occupied time schedule. If this variable is set to NO, then
the period's occupied time schedule will not be used on Tues-
day. This variable can be set for Periods 1 through 8.
WEDNESDAY IN PERIOD (PER.X
This 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
variable is used to include or remove Thursday from the sched-
ule. 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.
97
1 2
Start/Stop
Start No Override
Stop
Stop
Start No Override
The hour and minute
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 vari-
 
DAYS
 
DAYS THU) — This
3
Override
Override
Override
WED) —