Orion System System Manager TS II In-House - Manual (Page 51)

SMTS II Technical Guide
VCM, VCM-X & VCB-X Controllers
51
VCB-X Controllers
Economizer Enable Setpoint
If an Outdoor Air Temperature Sensor is connected to the VCB-X and
the Outdoor Air Temperature falls below this Setpoint, the Economizer
can be used for Free Cooling. High limit = 80ºF / 26.66ºC; Low limit =
-30ºF / -34.44ºC; Default = 55ºF / 12.80ºC.
Pre-Heat Enable Temperature
For cold climates where freezing temperatures may be experienced, a
Pre-Heater relay output can be activated to control a preheater coil based
on the Outdoor Air Temperature to prevent freezing of Water Coils. One
of the VCB-X Relay Outputs must be confi gured for the Pre-Heater
control. When confi gured, any time the Outdoor Air Temperature falls
below the Preheat Setpoint (during Occupied or Unoccupied Mode)
and the HVAC unit’s fan is running, the Pre-Heater relay will activate.
High limit = 70ºF / 21.11ºC; Low limit = -30ºF / -34.44ºC; Default =
30ºF / -1.11ºC.
Low Ambient Temperature
Similar to the Pre-Heat Relay, a Low Ambient Relay can be confi gured
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. High limit = 70ºF / 21.11ºC; Low
limit = -30ºF / -34.46ºC; Default = 30ºF / -1.11ºC.
Warmup Target Temperature
If the Return Air Temperature is below this value on a change to the
Occupied Mode, the unit will enter the Warm-Up Mode until this target
temperature is satisfi ed or times out (based on Warmup Mode Timeout
Period). High limit = 90ºF / 32.2ºC; Low limit = 50ºF / 10ºC; Default
= 70ºF / 21ºC.
Space Sensor Slide Adjustment
If the VCB-X Controller has a Space Temperature Sensor with the Slide
Adjust option installed, the HVAC Mode Enable Heating and Cooling
Setpoints can be offset by the HVAC Mode Sensor Slide Offset Setpoint
value. When the Slide Adjust bar is in the middle, no offset will occur.
If the Slide Adjust bar is moved all the way to the top of the Sensor, the
Heating and Cooling Setpoints will be raised by the Setpoint value you
have entered. If the Slide Adjust bar is moved all the way down to the
bottom of the Sensor, the Heating and Cooling Setpoints will be lowered
by the Setpoint value you have entered.
If the Space Temperature is the SAT Reset Source, then the Slide Adjust
will adjust the HVAC Mode Enable Setpoints and the SAT Reset Source
Setpoints simultaneously. High limit = 10ºF / 5.5ºC; Low limit = 0ºF /
0ºC; Default = 0ºF / 0ºC.
VCB-X Temperature Setpoints
Coil Setpoint Reset Limits
Based on the Indoor Humidity Reset Range confi gured with the Indoor
Humidity Low and High Reset Limits and the Coil Suction Temperature
Setpoint can be reset between the High Reset Limit and Low Reset Limit
confi gured on this screen during the Dehumidifi cation Mode. If the High
Reset Limit and the Low Reset Limit are set at the same value, no Coil
Temperature Reset will occur.
Coil Setpoint High Reset Limit
The Coil Temperature Setpoint can be reset to this maximum level when
the Indoor Humidity drops to its Low Reset Limit. See Reset descrip-
tion on page 59. If no reset of the Coil Temperature is required, set this
value the same as the following Coil Setpoint Low Reset Limit. High
limit = 70ºF / 21.1ºC; Low limit = 35ºF / -1.7ºC; Default = 45ºF / 7.2ºC.
Coil Setpoint Low Reset Limit
The Coil Temperature Setpoint can be reset to this minimum level when
the Indoor Humidity rises to its High Reset Limit. See Reset description
on page 59. If no reset of the Coil Temperature is required, set this value
the same as the above Coil Setpoint High Reset Limit. High limit = 70ºF
/ 21.1ºC; Low limit = 35ºF / -1.7ºC; Default = 40ºF / 4.4ºC.
Heat Wheel Defrost Temperature
The Heat Wheel Defrost Mode occurs when the Outdoor Air Temperature
is below this setpoint. High limit = 50ºF / 10ºC; Low limit = 0ºF / 0ºC;
Default = 30ºF /-1.7ºC.
Supply Air Cooling High Reset Limit
If No Reset has been confi gured for the SAT Reset Source, then this
setpoint will be the Cooling Mode Supply Air Setpoint. If a Reset Source
has been confi gured, then this setpoint will be the lowest temperature
the Supply Air Setpoint can be reset to. High limit = 80ºF / 26.66ºC;
Low limit = 30ºF / -1.11ºC; Default = 55ºF / 12.80ºC.
Supply Air Cooling High Reset Limit
If a SAT Reset Source has been confi gured, then this is the maximum that
the Cooling Mode Supply Air Setpoint can be reset up to. High limit =
100ºF / 37.77ºC; Low limit = 1ºF / -17.22ºC; Default = 55ºF / 12.80ºC.
Setpoints for Unit 0001
Coil Setpoint High Reset Limit 45 °F
Coil Setpoint Low Reset Limit
Heat Wheel Defrost Temperature
40
30
°F
°F
Temperatures
Page 4 of 9
Figure 97: VCB-X Temperature Screen 4
Setpoints for Unit 0001
Supply Air Cooling Setpoint
Cooling Reset Source Low Limit
55
70
°F
Supply Air Cooling High Reset Limit
Cooling Reset Source High Limit
55
75
°F
°F
°F
Temperatures
Page 5 of 9
Figure 98: VCB-X Temperature Screen 5