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14.3 Basic Sequence of Operation
All sequence of operation information for units controlled
with ALC controls is available in the ALC Sequence of
Operation documents that can be downloaded from the
Addison website at www.addison-hvac.com.
• Sequence of operation information specifically for
the operation of the gas furnace and electric heater
modules can be found on Page 28, Section 11.5.
For sequence of operation information for units controlled
with field-supplied DDC controls (whether factory-
mounted or field-mounted), consult the DDC controls
manufacturer and/or installer.
14.4 Controls Options
Controls options include, but are not limited to:
• Carbon Dioxide Detector:
This option provides a
room-mounted carbon dioxide detector for initiating
additional outdoor ventilation.
• Clogged Filter Indicator:
This section provides a
differential pressure switch and status indication.
• Exhaust Fan Interlock Switch:
This option provides
an interlock between an exhaust fan and the unit.
• Firestat:
This option de-energizes the unit when
the stat, mounted in the return air section, senses
return air above 135 °F (57.2 °C). The firestat must be
manually reset.
• Freezestat:
This option shuts down the unit when
the discharge temperature falls below the
controller’s setpoint.
• Service Receptacle:
This option provides a 115V
service receptacle with 15A breaker. It is mounted in a
2” x 4” (51cm x 10.2cm) enclosure. It can be field-wired
or factory-wired.
• Smoke Detector:
This option provides an ionization
type supply air smoke detector which shuts off the
unit if smoke is detected.
• Condensate Overflow Switch: Stops unit in case of
condensate drain blockage/full condensate drain pan.
• Convenience Outlet: Factory or field-powered 120VAC
GFCI convenience outlets with circuit breaker.
• Smoke Detector: Supply air smoke detectors are
field-installed and shipped loose for installation in
the ductwork.
PR Series Installation, Operation, and Maintenance Manual
