RT-SVX073A-EN
87
Table 39. External supply fan control points
(continued)
Object
Name
Description
Supply Fan
Speed
Limited
Supply fan speed is being increased or decreased due
to a limit control action.
Supply Fan
Speed
Setpoint
External supplied supply fan speed setpoint value
Supply Fan
Speed
Setpoint
Active
Active setpoint input to supply fan speed control
Supply Fan
Speed
Status
Indicates the requested speed to the supply fan, 0%
when fan is off.
Table 40. Supply fan speed setpoint summary
Supply Fan Speed
Setpoint Enable
Supply Fan Speed
Setpoint
Supply fan
operation
Disable NA Fan under Symbio
800 control
Enable 0% Commands the fan off
Enable 1% to 37%
(a)
Fan operates at drive
minimum Hz setting
Enable 38% to 100% Fan ramps between
drive min-Hz and
max-Hz setting.
(a)
For example, if drive setting is 22 min-Hz and 60 max-Hz, it will correlate to
37% reported fan speed.
External Relief Fan Control
External Relief fan control is allowed anytime a relief fan is
configured. Supply fan and relief fan operation is proven
before external fan control is allowed. Relief fan operation
is effectively interlocked with supply fan operation. No other
control limits are applied; building static pressure high limit
is not enforced.
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 41. External relief fan control points
Object Name
(a)
Description Object States or
values
Exhaust Fan Speed
Setpoint Enable
Enables Relief fan
speed setpoint control
0 = Disable
1 = Enable
Exhaust Fan Speed
Control Enabled
Relief fan speed is
control via Exhaust
Fan Speed Setpoint.
If disabled/inactive,
speed control is under
local control.
0 = Disabled
1 = Enabled
Exhaust Fan Speed
Setpoint
External supplied
exhaust fan speed
setpoint value
0 to 100%
Exhaust Fan Speed
Setpoint Active
Active setpoint input
to relief fan speed
control
0 to 100%
Exhaust Fan Speed
Status
Indicates the
requested speed to
the relief fan, 0%
when fan is off.
0 to 100%
(a)
Reference Integration Guide ACC-SVP02B (or later)
Table 42. Relief fan speed setpoint summary
Relief Fan Speed
Setpoint Enable
Relief Fan Speed
Setpoint
Relief fan
operation
Disable NA Fan under local
control
Enable 0% Commands the fan off
Enable 1% to min speed% Fan operates at drive
minimum setting
(a)
Enable >min speed% to
100%
Fan ramps between
motors min-rpm and
the Relief Fan
Maximum Speed
Setpoint (rpm),
adjustable at the
unit’s user interface
display, service
settings screen.
(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).
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 user interface display. However, the controller
must be configured with an Economizer damper.
• Economizer Airside Enable Default = Disabled
• Demand Control Ventilation Enable = Disabled
• Traq Enable = Disabled
Unit Startup
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