Carrier WeatherExpert 48N2 Controls, Start-Up, Operation, Service, And Troubleshooting page 118

ITEM
COOL COOLING INFORMATION
C.CAP Current Running Capacity
CUR.S Current Cool Stage
REQ.S Requested Cool Stage
MAX.S Maximum Cool Stages
DEM.L
Active Demand Limit
SUMZ COOL CAP. STAGE CONTROL
SMZ Capacity Load Factor
ADD.R Next Stage EDT Decrease
SUB.R Next Stage EDT Increase
R.PCT Rise Per Percent Capacity
Y.MIN
Cap Deadband Subtracting
Y.PLU Cap Deadband Adding
Z.MIN Cap Threshold Subtracting
Z.PLU Cap Threshold Adding
H.TMP High Temp Cap Override
L.TMP Low Temp Cap Override
PULL
Pull Down Cap Override
SLOW Slow Change Cap Override
HMZR HUMIDIMIZER
CAPC Humidimizer Capacity
C.EXV Condenser EXV Position
B.EXV Bypass EXV Position
RHV
Humidimizer 3-Way Valve
C.CPT Cooling Control Point
EDT Evaporator Discharge Tmp
H.CPT Heating Control Point
LAT Leaving Air Temperature
EXVS EXVS INFORMATION
A1.EX
Circuit A EXV 1 Position
A2.EX Circuit A EXV 2 Position
B1.EX Circuit B EXV 1 Position
B2.EX Circuit B EXV 2 Position
SH.A1 Cir A EXV1 Superheat Tmp
SH.A2 Cir A EXV2 Superheat Tmp
SH.B1
Cir B EXV1 Superheat Tmp
SH.B2 Cir B EXV2 Superheat Tmp
CTRL EXVS CONTROL INFORMATION
C.SHS EXV Superheat Ctrl SP
C.FLS EXV SH Flooding Ctrl SP
C.EXP EXV PID Ctrl Prop. Gain
C.EXT
EXV Ctrl Integrat. Time
C.EXM Cir Strt EXV Mn Ctrl Pos
Cap Threshold Subtracting (Z.MIN)
This parameter is used in the calculation of SMZ and is calcu-
lated as follows:
Z.MIN = Configuration  COOL  Z.GN *
(–10 + (4* (–SUB.R))) * 0.6
Cap Threshold Adding (Z.PLU)
This parameter is used in the calculation of SMZ and is calcu-
lated as follows:
Z.PLU = Configuration  COOL  Z.GN *
(10 + (4* (–ADD.R))) * 0.6.
High Temp Cap Override (H.TMP)
If stages of mechanical cooling are on and the error is greater
than twice Y.PLU, and the rate of change of error is greater
than 0.5F, then a stage of mechanical cooling will be added
every 30 seconds. This override is intended to react to situa-
tions where the load rapidly increases.
Table 85 — Cooling Information Display Table
EXPANSION
0-100
0-20
0-20
0-20
0-100
–400-400
0-30
0-30
0-10
–40-0
0-40
–99-0
0-99
No/Yes
No/Yes
No/Yes
No/Yes
0-100
0-100
0-100
No/Yes
–20-140
–40-240
–20-140
–40-240
0-100
0-100
0-100
0-100
–100-200
–100-200
–100-200
–100-200
5-40
0-10
0-5
0.5-60
0-100
118
RANGE UNITS CCN POINT
% CAPTOTAL
COOL_STG
CL_STAGE
CLMAXSTG
% DEM_LIM
SMZ
^F ADDRISE
^F SUBRISE
RISE_PCT
Y_MINUS
Y_PLUS
Z_MINUS
Z_PLUS
HI_TEMP
LOW_TEMP
PULLDOWN
SLO_CHNG
HMZRCAPC
COND_EXV
BYP_EXV
HUM3WVAL
COOLCPNT
EDT
HEATCPNT
LAT
% XV1APOSP
% XV2APOSP
% XV1BPOSP
% XV2BPOSP
^F SH_A1
^F SH_A2
^F SH_B1
^F SH_B2
^F SH_SP_CT
^F FL_SP_CT
EXV_PG_C
EXV_TI_C
% EXCSMP_C
Low Temp Cap Override (L.TMP)
If the error is less than twice Y.MIN, and the rate of change of
error is less than –0.5F, then a mechanical stage will be re-
moved every 30 seconds. This override is intended to quickly
react to situations where the load is rapidly reduced.
Pull Down Cap Override (PULL)
If the error from set point is above 4F, and the rate of change
is less than –1F per minute, then pulldown is in effect, and
"SUM" is set to 0. This keeps mechanical cooling stages from
being added when the error is very large, but there is no load in
the space. Pulldown for units is expected to rarely occur, but is
included for the rare situation when it is needed. Most likely
pulldown will occur when mechanical cooling first becomes
available shortly after the control goes into an occupied mode
(after a warm unoccupied mode).
Slow Change Cap Override (SLOW)
With a rooftop unit, the design rise at 100% total unit capacity is
generally around 30F. For a unit with 4 stages, each stage rep-
resents about 7.5F of change to EDT. If stages could reliably be
WRITE STATUS
forcible