104
Hot Gas Bypass
The ComfortLink control system supports the use of an optional
minimum load hot gas bypass valve (MLV) that is directly con-
trolled by the ComfortLink control system. This provides an addi-
tional stage of capacity as well as low load coil freeze protection.
Hot gas bypass is an active part of the P-Series ComfortLink ca-
pacity staging and minimum evaporator load protection functions.
It is controlled through the Minimum Load Valve function. The
hot gas bypass option consists of a solenoid valve with a fixed ori-
fice sized to provide a nominal 3-ton evaporator load bypass. A
hot gas refrigerant line routes the bypassed hot gas from the dis-
charge line of circuit A to the suction line of circuit A. An addi-
tional thermistor in the suction line allows the unit control to mon-
itor 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 installed on
Circuit A only. This function is enabled at Configura-
tion
COOL
MLV. When this function is enabled, an additional
stage of cooling capacity is provided by the unit control staging
sequences (see Appendix C, “UNIT STAGING TABLES” on
page 219).
Space Temperature Offset
Space Temperature Offset corresponds to a slider on a T56 sensor
that allows the occupant to adjust the space temperature by a con-
figured range during an occupied period. This sensor is only appli-
cable to units that are configured as Multi-Stage SPT control
(Configuration
UNIT
C.TYP = 4).
Space Temperature Offset Sensor (Configuration
UNIT
SENS
SP.O.S)
This configuration disables the reading of the offset slider.
Space Temperature Offset Range (Configuration
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
AIR.T
SPTO)
The Space Temperature Offset Value is the reading 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 Con-
trols Quick Start section on page 35 for more information on what
set points 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 85.
Table 85 — Time Clock Menu
ITEM EXPANSION RANGE UNITS CCN POINT
SP.O.S Space Temp Offset Sensor Enable/Disable SPTOSENS
SP.O.R Space Temp Offset Range 1 to 10 SPTO_RNG
SPTO Space Temperature Offset +- SP.O.R ^F SPTO
ITEM EXPANSION RANGE CCN POINT DEFAULT
TIME TIME OF DAY
HH.MM Hour and Minute 00:00 TIME
DATE MONTH,DATE,DAY AND YEAR
MNTH Month of Year multi-text strings MOY
DOM Day of Month 0 to 31 DOM
DAY Day of Week multi-text strings DOWDISP
YEAR Year e.g. 2012 YOCDISP
SCH.L LOCAL TIME SCHEDULE
PER.1 PERIOD 1
PER.1
DAYS DAY FLAGS FOR PERIOD 1 Period 1 only
PER.1
DAYS
MON Monday in Period YES/NO PER1MON Yes
PER.1
DAYS
TUE Tuesday in Period YES/NO PER1TUE Yes
PER.1
DAYS
WED Wednesday in Period YES/NO PER1WED Yes
PER.1
DAYS
THU Thursday in Period YES/NO PER1THU Yes
PER.1
DAYS
FRI Friday in Period YES/NO PER1FRI Yes
PER.1
DAYS
SAT Saturday in Period YES/NO PER1SAT Yes
PER.1
DAYS
SUN Sunday in Period YES/NO PER1SUN Yes
PER.1
DAYS
HOL Holiday in Period YES/NO PER1HOL Yes
PER.1
OCC Occupied from 00:00 PER1_OCC 00:00
PER.1
UNC Occupied to 00:00 PER1_UNC 24:00
Repeat for periods 2-8
HOL.L LOCAL HOLIDAY SCHEDULES
HD.01 HOLIDAY SCHEDULE 01
HD.01
MON Holiday Start Month 0 to 12 HOL_MON1
HD.01
DAY Start Day 0 to 31 HOL_DAY1
HD.01
LEN Duration (Days) 0 to 99 HOL_LEN1
Repeat for holidays 2-30
DAY.S DAYLIGHT SAVINGS TIME
DS.ST DAYLIGHT SAVINGS START
DS.ST
ST.MN Month 1 to 12 STARTM 4
DS.ST
ST.WK Week 1 to 5 STARTW 1
DS.ST
ST.DY Day 1 to 7 STARTD 7
DS.ST
MIN.A Minutes to Add 0 to 90 MINADD 60
DS.SP DAYLIGHTS SAVINGS STOP
DS.SP
SP.MN Month 1 to 12 STOPM 10
DS.SP
SP.WK Week 1 to 5 STOPW 5
DS.SP
SP.DY Day 1 to 7 STOPD 7
DS.SP
MIN.S Minutes to Subtract 0 to 90 MINSUB 60
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