114
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
–0.5F, then a mechanical stage will be removed every 30 sec-
onds. 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 4F, and the rate of change is less than –1F 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 unoccu-
pied 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 represents about
7.5F of change to EDT. If stages could reliably be cycled at
very fast rates, the set point could be maintained very precisely.
Since it is not desirable to cycle compressors more than 6 cy-
cles per hour, slow change override takes care of keeping the
PID under control when “relatively” close to set point.
EXV INFORMATION DISPLAY TABLE — The EXV in-
formation display table provides information on the unit cool-
ing EXVs.
VFD INFORMATION DISPLAY TABLE — The VFD in-
formation display table provides information on the supply fan
VFD and exhaust fan VFD. See Table 86.
OUTDOOR FAN VFD DISPLAY TABLE — The outdoor
fan VFDs display table provides information on the outdoof
fan VFD. Specifically the motor commanded speed, 0 to
100%.
MODE TRIP HELPER — The Mode Trip Helper table pro-
vides information on the unit modes and when the modes start
and stop. See Table 87. This information can be used to help
determine why the unit is in the current mode.
CCN/LINKAGE DISPLAY TABLE — The CCN/Linkage
display table provides information on unit linkage. See Table 88.
COMPRESSOR RUN HOURS DISPLAY TABLE — The
Compressor Run Hours Display Table displays the number of
run time hours for each compressor. See Table 89.
COMPRESSOR STARTS DISPLAY TABLE — The Com-
pressor Starts Display Table displays the number of starts for
each compressor. See Table 90.
SOFTWARE VERSION NUMBERS DISPLAY TABLE —
The Software Version Numbers Display Table displays the
software version numbers of the unit boards and devices. See
Table 91.
Table 86 — VFD Information Display Table
Table 87 — Mode Trip Helper Display Table
ITEM EXPANSION RANGE UNITS CCN POINT WRITE STATUS
VFDS VFD INFORMATION
S.VFD SUPPLY FAN VFD (VFD 1)
SPD VFD1 Actual Speed % VFD1_SPD
RPM VFD1 Actual Motor RPM VFD1RPM
FREQ VFD1 Actual Motor Freq VFD1FREQ
AMPS VFD1 Actual Motor Amps VFD1AMPS
TORQ VFD1 Actual Motor Torque VFD1TORQ
PWR VFD1 Actual Motor Power VFD1PWR
VDC VFD1 DC Bus Voltage VFD1VDC
V. OU T VFD1 Output Voltage VFD1VOUT
TEMP V F D1 Tra n s is to r Te m p ( C ) V F D 1T EM P
RUN.T VFD1 Cumulative Run Time VFD1RUNT
KWH VFD1 Cumulative kWh VFD1KWH
LFC VFD1 Last Fault Code VFD1LFC
E.VFD EXHAUST FAN VFD (VFD 2)
SPD VFD2 Actual Speed % VFD2_SPD
RPM VFD2 Actual Motor RPM VFD2RPM
FREQ VFD2 Actual Motor Freq VFD2FREQ
AMPS VFD2 Actual Motor Amps VFD2AMPS
TORQ VFD2 Actual Motor Torque VFD2TORQ
PWR VFD2 Actual Motor Power VFD2PWR
VDC VFD2 DC Bus Voltage VFD2VDC
V. OU T VFD2 Output Voltage VFD2VOUT
TEMP V F D2 Tra n s is to r Te m p ( C ) V F D 2T EM P
RUN.T VFD2 Cumulative Run Time VFD2RUNT
KWH VFD2 Cumulative kWh VFD2KWH
LFC VFD2 Last Fault Code VFD2LFC
O.VFD OUTDOOR FAN VFDS
SPD.A MtrMaster A Commanded % 0 to 100 % MM_A_VFD
SPD.B MtrMaster B Commanded % 0 to 100 % MM_B_VFD
ITEM EXPANSION RANGE UNITS CCN POINT WRITE STATUS
TRIP MODE TRIP HELPER
UN.C.S Unoccup. Cool Mode Start UCCLSTRT
UN.C.E Unoccup. Cool Mode End UCCL_END
OC.C.S Occupied Cool Mode Start OCCLSTRT
OC.C.E
Occupied Cool Mode End OCCL_END
TEMP Ctl.Temp RAT,SPT or Zone CTRLTEMP
OC.H.E Occupied Heat Mode End OCHT_END
OC.H.S Occupied Heat Mode Start OCHTSTRT
UN.H.E Unoccup. Heat Mode End UCHT_END
UN.H.S Unoccup. Heat Mode Start UCHTSTRT
HVAC ascii string spelling out the hvac modes string
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