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VAV/Zone Controller Package
SEQUENCE OF OPERATIONS
Zoning
Zoning
The Orion Control System can be confi gured to operate as a true
zoning system with the addition of a MiniLink PD 5. The Mini-
Link PD 5 acts as a loop manager receiving information from
the VAV/Zone Controller Packages, interpreting this information,
and then sending a heat, cool, or vent signal to the Unit Control-
ler. Only 16 zones can be confi gured as voting zones per loop.
Additional zones will be non-voting.
Zone Polling
The MiniLink PD 5 must be confi gured for zoning operation
using the Modular Service Tool SD, System Manager SD, or
Prism 2 computer software. During the setup and confi guring,
the user is required to enter the last Zone address on the loop.
Once confi gured, the MiniLink PD 5 begins polling each VAV/
Zone Controller for its temperature and setpoint information. A
zone poll cycles through all confi gured zones in one pass without
interruption.
The following is a list of status information required by the
MiniLink PD 5 to correctly perform its HVAC mode calculations.
Zone Temperature
Current Cooling Setpoint
Current Heating Setpoint
Current Zone Operating Mode Status & Alarm
Conditions
A zone is considered Missing if it fails to respond to 5 consecu-
tive polling requests. A Missing Zone alarm can be generated
in less than 2 minutes. This alarm can generate an alarm callout
to maintenance or a supervisor if the system has been properly
setup. See the “Alarm Detection And Reporting” section for
more information.
Zone Voting
If a zone has been confi gured for the Voting mode, the Mini-
Link will perform the following tests based on the data received
during the zone polling operation. These tests ensure that only
properly operating zones can have an eff ect on the HVAC Mode
calculation.
The zone has not been reported as Missing
The zone is not currently undergoing Damper
Calibration
The zone damper does not have an alarm condition
The zone temperature readings are between 40°F
and 105ºF
The Zone Cooling Setpoint is between 55°F and
105ºF
The Zone Heating Setpoint is between 48°F and 99°F
The zone has not been declared Maverick by the
MiniLink
The zone has been confi gured as a Voting zone
If
all
the above tests are passed, the zone temperature and set-
points are then included in the HVAC mode decision; otherwise,
this zone is ignored.
Testing for Maverick Zones
During the HVAC mode decision process, a zone cannot be in-
cluded in the Voting if it has been declared as Maverick. A zone
is determined to be a Maverick if it stays 4ºF below the Space
Heating Setpoint for 1 hour or 4ºF above the Space Cooling Set-
point for 1 hour. During this 1 hour time period, the zone is still
included in the voting, but it generates a Priority call for Heating
or Cooling to the MiniLink. During this 1 hour time period, if
the Space Temperature moves to within 2ºF of its Space Heating
or Space Cooling Setpoint, the Priority and Maverick are both
canceled. If the zone stays in Priority for greater than 1 hour,
it then becomes a Maverick zone. At that point, its Priority is
canceled and the zone is ignored in the voting process until the
Space Temperature changes to within 2ºF of its Space Heating or
Space Cooling Setpoint. If at least 75% of the zones go Maverick
simultaneously, the MiniLink assumes an abnormal condition has
occurred in the building and resets all the zones back to normal.
It then restarts the 1 hour Maverick test over again for all zones.
Maverick testing can be disabled if your system is connected to
a computer with Prism 2, the Modular System Manager SD, or
the Modular Service Tool SD.
