52
Table 37 — Run Status Mode Trip Helper
The controlling temperature is “TEMP” and is in the middle of
the table for easy reference. The HVAC mode can also be
viewed at the bottom of the table.
For non-linkage applications and VAV control types (C.TYP = 1
or 2), “TEMP” is the controlling return air temperature
(R.TMP). For space sensor control, “TEMP” is the controlling
space temperature average occupied zone temperature (S.TMP).
For linkage applications, “TEMP” is zone temperature: average
occupied zone temperature (AOZT) during occupied periods and
average zone temperature (AZT) during unoccupied periods.
SUMZ COOLING ALGORITHM
The SumZ cooling algorithm is an adaptive PID (proportional,
integral, derivative) which is used by the control whenever more
than 2 stages of cooling are present (C.TYP = 1, 2, 3, and 4).
This section will describe its operation and define the pertinent
parameters. It is generally not necessary to modify parameters in
this section. The information is presented primarily for reference
and may be helpful for troubleshooting complex operational
problems.
The only configuration parameter for the SumZ algorithm is
located at the local display under Configuration
COOL
Z.GN. See Table 35.
Capacity Threshold Adjust (Z.GN)
This configuration affects the cycling rate of the cooling stages
by raising or lowering the threshold that capacity must build to
in order to add or subtract a stage of cooling.
The cooling algorithm’s run-time variables are located at the
local display under Run Status
COOL. See Table 38.
Current Running Capacity (C.CAP)
This variable represents the amount of capacity currently run-
ning in percent.
Current Cool Stage (CUR.S)
This variable represents the cool stage currently running.
Requested Cool Stage (REQ.S)
This variable represents the requested cool stage. Cooling relay
timeguards in place may prevent the requested cool stage from
matching the current cool stage.
Maximum Cool Stages (MAX.S)
This variable is the maximum number of cooling stages the
control is configured for and capable of controlling.
Active Demand Limit (DEM.L)
If demand limit is active, this variable will represent the
amount of capacity that the control is currently limited to.
Capacity Load Factor (SMZ)
This factor builds up or down over time and is used as the
means of adding or subtracting a cooling stage during run time.
It is a normalized representation of the relationship between
“Sum” and “Z”. The control will add a stage when SMZ reach-
es 100 and decrease a stage when SMZ equals –100.
Table 38 — Run Status Cool Display
ITEM EXPANSION UNITS
CCN
POINT
TRIP MODE TRIP HELPER
UN.C.S Unoccup. Cool Mode Start dF UCCLSTRT
UN.C.E Unoccup. Cool Mode End dF UCCL_END
OC.C.S Occupied Cool Mode Start dF OCCLSTRT
OC.C.E Occupied Cool Mode End dF OCCL_END
TEMP Ctl.Temp R.TMP,S.TMP or Zone dF CTRLTEMP
OC.H.E Occupied Heat Mode End dF OCHT_END
OC.H.S Occupied Heat Mode Start dF OCHTSTRT
UN.H.E Unoccup. Heat Mode End dF UCHT_END
UN.H.S Unoccup. Heat Mode Start dF UCHTSTRT
HVAC the current HVAC MODE String
ITEM EXPANSION RANGE UNITS CCN POINT WRITE STATUS
COOL COOLING INFORMATION
C.CAP Current Running Capacity % CAPTOTAL
CUR.S Current Cool Stage COOL_STG
REQ.S Requested Cool Stage CL_STAGE
MAX.S Maximum Cool Stages CLMAXSTG
DEM.L Active Demand Limit % DEM_LIM forcible
SUMZ COOL CAP. STAGE CONTROL
SMZ Capacity Load Factor –100 to +100 SMZ
ADD.R Next Stage EDT Decrease ^F ADDRISE
SUB.R Next Stage EDT Increase ^F SUBRISE
R.PCT Rise Per Percent Capacity RISE_PCT
Y.MIN Cap Deadband Subtracting Y_MINUS
Y.PLU Cap Deadband Adding Y_PLUS
Z.MIN Cap Threshold Subtracting Z_MINUS
Z.PLU Cap Threshold Adding Z_PLUS
H.TMP High Temp Cap Override HI_TEMP
L.TMP Low Temp Cap Override LOW_TEMP
PULL Pull Down Cap Override PULLDOWN
SLOW Slow Change Cap Override SLO_CHNG
HMZR HUMIDIMIZER
CAPC Humidimizer Capacity HMZRCAPC
C.EXV Condenser EXV Position COND_EXV
B.EXV Bypass EXV Position BYP_EXV
RHV Humidimizer 3-Way Valve HUM3WVAL
C.CPT Cooling Control Point COOLCPNT
EDT Evaporator Discharge Tmp EDT
H.CPT Heating Control Point HEATCPNT
LAT Leaving Air Temperature LAT
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