VCC-X Operator Interface SD
VCC-X SETPOINTS
51
Setpoint Screen #39 - Supply Air Cutoffs -
Cooling/Heating
VCC-X Spts ID:#
Supply Air Cutoffs
Cooling: 40.0
º
F
Heating: 150.0
º
F
The VCC-X controller will temporarily disable Heating or Cooling
if while in Heating or Cooling Mode the Supply Air Temperature
rises above the SAT Heating Cutoff Setpoint or falls below the
SAT Cooling Cutoff Setpoint. See the
VCC-X Controller Technical
Guide
for detailed information on the Low and High Supply Air
Temperature Cutoff sequence of operation.
Description
Minimum
Default
Maximum
Cooling SAT Cutoff
0ºF
(-17.7
º
C)
40ºF
(4.5
º
C)
100ºF
(37.7
º
C)
Heating SAT Cutoff
0ºF
(-17.7
º
C)
150ºF
(65.5
º
C)
250ºF
(121.1
º
C)
Setpoint Screen #40 - Hot Water Valve
Protection Position
VCC-X Spts ID:#
Hot Water Valve
Protection Pos: 0%
If the Supply Fan is on and the Supply Air Temperature (SAT) falls
below the Low SAT Cutoff Setpoint for 1 minute, the Hot Water
Valve will move to this position. If the SAT rises 5°F above the Low
SAT Cutoff, the valve will return to normal operation. If the SAT
remains below the Low SAT Cutoff Setpoint for 10 minutes, the
unit will shut down and a Low SAT Cutoff Alarm will be generated.
If the Supply Fan is off or during Emergency Shutdown and the
Outdoor Air Temperature (OAT) falls below the Low Ambient Set-
point, the Hot Water Valve will move to this position. If the OAT
rises back above the Low Ambient Setpoint, the valve will return
to its normal position.
If this setpoint is left at the default value of 0%, then the controller
will not initiate this protection sequence.
For SCR heat this should
be left at 0%.
Description
Minimum
Default
Maximum
Hot Water Valve
Protection Position
0%
0%
100%
Setpoint Screen #41 - Preheat Relay Setpoint
VCC-X Spts ID:#
Preheat Relay
Setpoint: 30.0
º
F
For cold climates where freezing temperatures may be experienced,
a Pre-Heater relay output can be activated to control a preheat coil
based on the Outdoor Air Temperature to prevent freezing of Water
Coils. One of the VCC-X Relay Outputs must be con
fi
gured for the
Pre-Heater control. When con
fi
gured, any time the Outdoor Air Tem-
perature falls below the Preheat Setpoint during Occupied Mode and
the HVAC unit’s fan is running, the Pre-Heater relay will activate.
This setpoint will also be used to enable the PREHEAT-X Control-
ler if it is being used in conjunction with the VCC-X Controller.
IF the PREHEAT-X Controller is being used with the VCC-X Con-
troller, a relay on the VCC-X cannot also be con
fi
gured as Preheat
and energize for Preheat function.
Description
Minimum
Default
Maximum
Preheat Setpoint
-30ºF
(-34.4
º
C)
30ºF
(-1.1
º
C)
70ºF
(21.1
º
C)
Setpoint Screen #42 - Low Ambient Setpoint
VCC-X Spts ID:#
Low Ambient
Setpoint: 30.0
º
F
Similar to the Pre-Heat Relay, a Low Ambient Relay can be con
fi
g-
ured to energize anytime (during Occupied or Unoccupied Mode)
the Outdoor Air Temperature falls below this setpoint. The Low
Ambient Relay, though, can energize whether the fan is running or
not. This could be used to energize a boiler, for instance.
Description
Minimum
Default
Maximum
Low Ambient Setpoint
-30ºF
(-34.4
º
C)
30ºF
(-1.1
º
C)
70ºF
(21.1
º
C)
Setpoint Screen #43 - Heat Pump Defrost
Interval
VCC-X Spts ID 102
Heat Pump Defrost
Interval: 30 Min
If this is a heat pump unit with a Defrost Coil Temperature Switch
installed and con
fi
gured, a Heat Pump Defrost Mode is available.
If the Defrost Coil Temperature Switch closes during Heat Pump
Heating operation, the unit will enter the Defrost Mode for 10
minutes or until the Defrost Coil Temperature Switch opens. The
VCC-X Setpoint Screens
