117
Slow Change Cap Override (SLOW)
With a rooftop unit, the design rise at 100% total unit capacity is
generally around 30F. For a unit with 4 stages, each stage rep-
resents 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 cycles per hour, slow change override takes care of keep-
ing the PID under control when “relatively” close to set point.
VFD INFORMATION DISPLAY TABLE
The VFD information display table provides information on
the supply fan VFD and exhaust fan VFD. See Table 98.
MODE TRIP HELPER
The Mode Trip Helper table provides information on the unit
modes and when the modes start and stop. See Table 99. 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 100.
COMPRESSOR RUN HOURS DISPLAY TABLE
The Compressor Run Hours Display Table displays the number
of run time hours for each compressor. See Table 101.
COMPRESSOR STARTS DISPLAY TABLE
The Compressor Starts Display Table displays the number of
starts for each compressor. See Table 102.
SOFTWARE VERSION NUMBERS DISPLAY TABLE
The Software Version Numbers Display Table displays the
software version numbers of the unit boards and devices. See
Table 103.
Table 98 — VFD Information Display Table
Table 99 — 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.OUT VFD1 Output Voltage VFD1VOUT
TEMP VFD1 Transistor Temp (C) VFD1TEMP
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.OUT VFD2 Output Voltage VFD2VOUT
TEMP VFD2 Transistor Temp (C) VFD2TEMP
RUN.T VFD2 Cumulative Run Time VFD2RUNT
KWH VFD2 Cumulative kWh VFD2KWH
LFC VFD2 Last Fault Code VFD2LFC
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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