Catalogue

46 UV-PRC004-EN
Controls
Two Systems in One
In an ICS environment, the Tracer ZN520 is pre-designed to install quickly and easily into the
system. Since the controller and the unit are factory tested and commissioned, the start-up time
for the entire system is minimized. Trane becomes the single source of responsibility for the
equipment, unit controls, and building automation system.
As a standalone controller, the Tracer ZN520 is ideally suited for fix-on-fail replacement of units
with old pneumatic controllers, or in situations where a BAS will be added at a later date. Once
power is applied to the controller, it will automatically start up and run based upon the setpoint on
the local zone sensor. An individual time clock can be added to the unit for local scheduling.
The Tracer ZN520 is certified to the interoperable L
ONMARK
®
Space Comfort Controller profile. This
allows the controller to be used with another vendor’s BAS and thereby still provide the high quality
of factory installation and testing. In addition, the Tracer ZN520 provides one of the most extensive
interoperable data lists of any controller of its type in the industry.
Tracer ZN520 Features Include:
Automatic Fan and Ventilation Reset. With the Tracer ZN520 controller, a two speed fan
control for the unit ventilator delivers the airflow output customized to support the cfm space
needs. When less cfm is necessary to meet the load of the classroom (typically 75 to 80 percent of
the time), the equipment operates on low speed. However, if the room temperature rises, the
controller will switch to high speed, and the outside air damper will adjust to satisfy the space
needs. This helps maintain the proper amount of ventilation air to the occupants independent of
the fan speed. As part of the ventilation strategy, the controller will reposition the outside air
damper to confirm the minimum outside air cfm is met at both operating conditions.
Manual Output Test . The Tracer ZN520 controller includes a manual output test function. This
function may be initiated from the blue test push button on the controller or through the Rover
service tool. This feature is used to manually exercise the outputs in a defined sequence.
The purpose of this test sequence is to verify output and end device operation. The manual output
test function may also be used in the following situations:
• Reset latching diagnostics
• Verify output wiring and operation
Figure 13. Tracer ZN520 system
Tracer ZN520
UV-PRC004-EN.book Page 46 Monday, February 4, 2013 11:01 AM