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Important: A valid space static pressure sensor is not
required for external relief fan control;
therefore, proper building static pressure
control must be considered.
The controller will annunciate External Relief Fan Control
on the user interface, operating modes screen, when
active. All modes of operation are supported, except when
supply fan is off. If the supply fan cycles off with capacity,
the relief fan will also turn off. External relief fan speed is
also interlocked with relief damper position and relief
damper diagnostics. The relief damper movement will limit
relief fan speed changes accordingly. The controller will
impose speed limitations as required.
Table 38.
External relief fan control points
Object Name
(a)
Description
Exhaust Fan Speed
Enables Relief fan
Setpoint Enable
speed setpoint control
Exhaust Fan Speed
Relief fan speed is
Control Enabled
control via Exhaust
Fan Speed Setpoint.
If disabled/inactive,
speed control is under
local control.
Exhaust Fan Speed
External supplied
Setpoint
exhaust fan speed
setpoint value
Exhaust Fan Speed
Active setpoint input
Setpoint Active
to relief fan speed
control
Exhaust Fan Speed
Indicates the
Status
requested speed to
the relief fan, 0%
when fan is off.
(a)
Reference Integration Guide ACC-SVP02B (or later)
Table 39. Exhaust fan speed setpoint summary
Exhaust Fan
Exhaust Fan
Speed Setpoint
Speed Setpoint
Enable
Disable
NA
Enable
0%
Enable
1% to min speed%
Enable
>min speed% to
100%
(a)
The drive minimum RPM setting is 10 percent of nameplate rated speed. The
min speed% is equal to: 100 x (drive minimum RPM / Relief Fan Maximum
Speed Setpoint).
RT-SVX063G-EN
Object States or
values
0 = Disable
1 = Enable
0 = Disabled
1 = Enabled
0 to 100%
0 to 100%
0 to 100%
Exhaust fan
operation
Fan under local
control
Commands the fan off
Fan operates at drive
minimum setting
(a)
Fan ramps between
motors min-rpm and
the Relief Fan
Maximum Speed
Setpoint (rpm),
adjustable at the
unit's front panel
display, service
settings screen.
External Outdoor Air Damper Control
To control the outdoor damper directly, via TGP2 or an
external control, a setpoint can be written to Economizer
Minimum Position Setpoint BAS. The controller will limit the
damper movement. The commanded position reports at
Outdoor Air Damper Position.
To have complete damper control, the following functions
should be disabled or removed from configuration via
Tracer TU or front panel display. However, the controller
must be configured with an Economizer damper.
•
Economizer Airside Enable Default = Disabled
•
Demand Control Ventilation Enable = Disabled
•
Traq Enable = Disabled
•
Outdoor Air Flow Compensation Enable = Disable
Morning Warm Up, Pre-Cool, Night Purge, Unoccupied,
and Off modes of operation will override damper minimum
position to 0%.
Overrides
The controller normally provides heating, cooling and
ventilation for building comfort. The below control functions
can intervene or override normal operation. These
functions allow control over the IntelliPak unit as well as a
means for the Service Technician to accomplish their tasks.
The order of priorities are listed. For example, an External
Stop will prevent the unit from performing Ventilation
Override.
1. Local Stop
2. Emergency Stop
3. External Stop
4. Manual Control
5. Ventilation Override
6. Emergency Override
7. Operating Mode Off
8. Normal operating modes
If local stop, emergency stop, or external stop request a
Stop, the unit will shut down and not resume operation until
all inputs allow automatic operation.
Local Stop
Local Stop is performed by the Front Panel Stop button on
the front panel display. The controller will perform a Normal
Shutdown process unless, the user additionally selects
Immediate Shutdown at the front panel when prompted.
Normal Shutdown Process
In a normal shutdown situation, compressors, fans, and
other systems of the unit are allowed to go through an
orderly shutdown sequence. For example, compressors
continue to run for any remaining Minimum Run time.
If a Service Tool requires the unit to be in Front Panel Stop
for an operation, e.g. binding, configuration, or software
Sequence of Operation
87
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