Orion System SA E-BUS Controller - Manual (Page 38)

Zone
Zone
Inputs & Outputs
SA E-BUS Controller Technical Guide 38
SA E-BUS Controller Inputs
SA E-BUS Controller Inputs
AI1 - Space Temperature Sensor Input
If you want to generate Occupied or Unoccupied Heating and Cool-
ing demands based on Space Temperature, select this Sensor for the
HVAC Mode enable. The Space Temperature Sensor can be used for
Night Setback control regardless of the HVAC Mode Sensor selected.
If the Space Temperature Sensor used is equipped with the optional
Push-Button Override Feature, this input will detect user overrides from
Unoccupied back to Occupied operation for a user-adjustable amount
of time. This Sensor is only required for Space Temperature Control or
Night Setback. The Space Temperature Sensor can also be confi gured
to reset the Supply Air Temperature Setpoint. The Space Temperature
Sensor is the only Sensor that can be used for Night Setback operation
during the Unoccupied Mode.
AI2 - Supply Air Temperature Sensor Input
The Supply Air Temperature Sensor is the default HVAC Mode Enable
Sensor. For typical VAV units that are Cooling Only with Morning
Warm-up, this Sensor should be confi gured as the HVAC Mode Enable
Sensor. For all applications, the Supply Air Temperature Sensor is the
sensor used for Staging Control. The HVAC unit must always have a
Supply Air Temperature Sensor installed.
AI3 - Entering Water Temperature Sensor
Input
The Entering Water Temperature is used to determine when to initiate
Water Side Economizer operation. If the unit is in Cooling Mode and
the Entering Water Temperature drops 10˚F (adj.) below the Entering Air
Temperature, the unit will begin to modulate the Water Side Economizer
Valve as part of the cooling operation. See Water Side Economizer in
the Sequence of Operation Section of this manual for a full description
of this operation.
AI4 - Entering Air Temperature Sensor Input
The Entering Air Temperature Sensor can be used as the controlling
sensor for 100% Entering Air units. The Entering Air Temperature is
used to lock out Heating or Cooling to conserve energy at whatever
temperature you deem appropriate for each Mode of Operation. The En-
tering Air Temperature Sensor can also be used to provide Low Ambient
Temperature Protection in the building. If the Entering Air Temperature
is below the Low Ambient Temperature Setpoint, the Preheat Relay
Output will be maintained during Occupied operation and will not be
allowed to stage off unless the Supply Fan is turned off. The Entering
Air Temperature Sensor is also used in combination with the Entering
Air Humidity Sensor for Dewpoint calculations.
AI5 - Not Utilized At This Time
AI6 - Duct Static Pressure Sensor Input
This special phone jack-style input connection accepts a Duct Static
Pressure Sensor input modular cable. The Duct Static Pressure Sensor
reading is used to determine current Duct Static Pressure. This Static
Pressure reading is used to control the output signal supplied to the Sup-
ply Fan VFD or Zoning Bypass Damper Actuator. If you have confi gured
the HVAC unit for Constant Volume operation, this Sensor is optional.
If it is installed on a Constant Volume unit, it will not affect operation,
but rather will be used as a status-only reading.
AI7 - Space Temperature Sensor Slide Adjust or
Remote SAT Reset Signal Input
AI7 on the SA E-BUS Controller is a dual-purpose input. It can be
used for the Space Sensor Slide Adjust option or for connection of the
Remote Supply Air Setpoint Reset Signal option. Only one or the other
can be used, not both.
Space Temperature Sensor Slide Adjust
If the Space Temperature Sensor being used has the optional Slide
Adjust feature, its AUX output is connected to this input. The Slide
Adjust control is used to vary the HVAC Mode Heating and Cooling
Setpoints by a user-confi gured maximum amount. The Slide Adjust-
ment adjusts whichever Temperature Sensor has been confi gured as
the HVAC Mode Enable Sensor, even if that Sensor is not the installed
Space Temperature Sensor.
If Space Temperature or Entering Air Temperature is confi gured as
the SAT/Reset Source, the Slide Adjustment adjusts both the HVAC
Mode Enable Heating and Cooling setpoints and the SAT/Reset Source
Heating and Cooling setpoints simultaneously by a user-confi gurable
maximum amount.
Remote Supply Air Temperature Reset Signal
When a 0-5 or 0-10 VDC Remote Supply Air Temperature Reset Signal
is to be used, the controller must be confi gured for it, and the Room
Sensor Slide Offset setpoint must be set to zero for this option. If the
slide offset is not set to zero, the Supply Air Temperature Reset will
not function.
The Remote Supply Air Temperature Reset signal must be confi gured so
that its setpoint will be at the coldest Supply Air Temperature at 0 VDC,
and so that its setpoint will be at the warmest Supply Air Temperature
at 5 or 10 VDC, depending on the voltage signal required.
The jumper AI7 must be set to 0-10V regardless of whether the control-
ler is confi gured for 0-5 or 0-10VDC operation. See the wiring diagram
on page 13 for details.