OCCUPIED COOLING MODE — The occupied cooling mode state begins when the conditioned zone temperature rises 2 degrees F plus maximum control overshoot above the morning warm-up setpoint setting. The unit control module conditions are as follows:

• The heat/cool mode output is de-energized.
• The economizer and mechanical cooling functions are permitted to operate in response to limit controls and supply air temperature.
• The cooling tower/condenser water pump interlock output cycles on and off based on the need for cooling.
• The supply air fan is on continuously.
• The airside economizer fresh air damper (if provided) is open to its minimum position or greater.

NIGHT HEAT/MORNING WARM-UP OVERRIDE — This feature consists of a switch which is mounted on the side of the night heat zone sensor. To initiate the override, the switch button must be pushed for 1 second. The unit will then return to the occupied mode for two hours. This time period is remotely adjustable from the Tracer^® with the Integrated Comfort™ system interface control option.

Night Heat Morning Warmup Control

This control option is identical to the Programmable Night Heat Morning Warmup Control described above except that the programmable timer is not provided. Therefore, an unoccupied input (a set of terminals) is provided to switch the unit into the unoccupied mode. The unit control is accomplished as follows:

• The Night Heat Mode is activated by a switch or contact closure to the unoccupied input.
• The Morning Warm-up Mode is initiated by a switch or contact opening to the unoccupied input.
• When the morning warm-up temperature setpoint is reached, the unit will switch over to the Occupied Heating Mode.
• The Occupied Cooling Mode state begins when the conditioned zone temperature rises 2 degrees F above the morning warm-up setpoint setting. The system must progress through the unoccupied mode to return to the occupied heating mode.

Integrated Comfort™ System Interface

This option allows interface between the Tracer^® Building Automation System and the self-contained unit through a two wire serial data link. The Tracer system provides external signals to the unit control module in a supervisory role to coordinate the operation of the self-contained unit with the rest of the building HVAC system.

SYSTEM OPERATION – In order for the Tracer system to act in a supervisory role the unit switch must be in the Auto Remote position. If the unit switch is in either the Auto Local or Stop/Reset positions, the Tracer system can interrogate the unit and gather information but cannot control the unit. Tracer system inputs to the unit will be stored but not used.

This option includes a non-volatile memory to hold in storage certain setpoints, data, and diagnostic codes in the event of a power outage or failure of the serial data link.

COMMUNICATIONS LINK – The communication link between a Tracer and the self-contained units is by a single twisted pair of wires. The self-contained units can be "daisychained" together with this single shielded twisted pair of wires resulting in substantially less installation cost than conventional "hardwired" energy management systems. The Tracer 100 system will accommodate a maximum of 12 self-contained units and up to eight Tracer 100 units can be linked to form a system capable of handling up to 96 self-contained units. A single Tracer 1000 system can accommodate up to 80 self-contained units.

OPERATING MODES – The following modes can be initiated or changed by the Tracer system:

Auto/Stop — Auto puts the self-contained unit into operation responding to internal (unit control module) and external (Tracer) control inputs. Stop shuts the unit down. In addition, a hardwired input to the External Interlock Auto/Stop may also be used.

Occupied/Unoccupied — The Tracer system directs the unit control module to operate in the Programmable Night Heat Morning Warmup mode. The unit will operate in the manner described above in the Programmable Night Heat Morning Warmup Control section with the Tracer system acting as the time clock. The Night Heat/Morning Warmup Override function is available but the unit control module will not respond to the override signal unless authorized by the Tracer system.

Fan On Ventilate — In this mode the fan is started, the ventilate output energized and the airside economizer fresh air damper (if present) driven full open. The cooling and heating functions are locked out. A hardwired Fan On Ventilate input may also be used.

SETPOINTS — With the Integrated Comfort Systems InterFace option, the following setpoints can be set from the Tracer system:

a. Supply air temperature on VAV units

b. Day cooling on non-VAV units

c. Supply air pressure on VAV units with inlet guide vanes

d. Morning warmup or day heat

c. Airside economizer minimum position

d. Night heat

e. Default supply air temperature on VAV units

f. Default day cooling on non-VAV units

g. Default supply air pressure on VAV unit with inlet guide vanes

All of the above items are stored in non-volatile memory.

STATUS MONITORING – The Integrated Comfort systems interface option provides an extensive monitoring capability which allows building operators and maintenance personnel easy access to a host of unit status and operating information at the Tracer computer. All of the diagnostic and operating state displays that are available at the unit