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Section 14:
Sequence of Operation:
DANGER
ELECTRICAL SHOCK HAZARD
Disconnect electric before service.
More than one disconnect switch
may be required to disconnect
electric from equipment.
Equipment must always be
properly grounded.
14.1 Unit Configuration
Based on the unit's application, the unit may be
configured in any number styles to achieve the described
functionality. Refer to the unit’s model number to see
which configuration the unit was supplied with.
14.2 Controls Options
Unit may be controlled in one of the following ways:
• ALC DDC controller with sensors (factory mounted)
• Factory-mounted DDC controls (by others)
• Factory-mounted terminal strip for field-mounted
• Factory-mounted terminal strip for electromechanical
controls (by factory or by others)
14.2.1 ALC DDC Controller With Sensors
(Factory Mounted)
The ALC control option consists of a factory programmed
controller and a series of factory-wired sensors. The
controller can operate in a 100% stand alone mode with
the use of a hand-held display. It can also connect to
a building automation system (BMS) using one of four
compatible protocols (BACnet®, LonWorks with the
optional Echelon card, Modbus, N2). The point mapping
to these protocols can be pre-set, so that the protocol and
baud rates desired can be easily field-selected without the
need for additional downloads or technician assistance.
Depending on the options ordered, remote sensors may
be installed and wired to the controller.
14.2.2 Factory-Mounted DDC Controls
(by others)
Field-supplied DDC controls are mounted by the factory
per the customer’s specifications.
14.2.3 Factory-Mounted Terminal Strip for
Field-Mounted DDC Controls (by others)
Field-supplied DDC controls can be connected to the
factory-mounted and factory-wired terminal strip.
14.2.4 Factory-Mounted Terminal Strip for
Electromechanical Controls
(by factory or by others)
A factory-supplied or field-supplied programmable
touchscreen thermostat can be connected to the
factory-mounted and factory wired terminal strip for
electromechanical controls.
The thermostat has a 45-90 °F [7-32 °C] temperature
control range with a +/- 1 °F [0.5 °C] accuracy and are
capable of connecting to optional factory-supplied remote
indoor air and outdoor air temperature sensors.
Figure 19: Equipment Touch Display
PR Series Installation, Operation, and Maintenance Manual
