Applications Guide Tracer Graphical Programming - Trane

Applications Guide Tracer Graphical Programming - Trane Applications Guide Tracer Graphical Programming - Trane

28.09.2014 Views

® Chapter 6 VAV AHU example Writing the alarms program The alarms program indicates diagnostic conditions to the operator and protects the equipment from potential harm when such a condition exists. According to the sequence of operation, the following diagnostic conditions require an alarm indication: • Dirty filter • Duct static pressure high limit • Exhaust fan failure • Low outdoor air temperature • Low (mixed air) temperature detection • Sensor failure (including discharge air temperature, mixed air temperature, outdoor air temperature, space temperature, and duct static pressure) • Supply fan failure The following failures shutdown the air handler and require a manual reset: • Discharge air or mixed air temperature sensor failure • Fan failure • High duct static pressure • Low mixed air temperature All alarms must be resettable at the operator display. First, set the program properties as shown in Figure 119 on page 129. 128 CNT-APG001-EN

® Writing the alarms program Figure 119: Alarms program properties Note that some alarms require the air handler to shut down, and others simply require an alarm indication. An alarm reset at the operator display resets all alarms. Taking this into consideration, create the following three modules within the alarms program: • Manual reset alarms • Auto-reset alarms • Alarm indication and reset CNT-APG001-EN 129

®<br />

Chapter 6 VAV AHU example<br />

Writing the alarms program<br />

The alarms program indicates diagnostic conditions to the operator and<br />

protects the equipment from potential harm when such a condition exists.<br />

According to the sequence of operation, the following diagnostic conditions<br />

require an alarm indication:<br />

• Dirty filter<br />

• Duct static pressure high limit<br />

• Exhaust fan failure<br />

• Low outdoor air temperature<br />

• Low (mixed air) temperature detection<br />

• Sensor failure (including discharge air temperature, mixed air temperature,<br />

outdoor air temperature, space temperature, and duct static<br />

pressure)<br />

• Supply fan failure<br />

The following failures shutdown the air handler and require a manual<br />

reset:<br />

• Discharge air or mixed air temperature sensor failure<br />

• Fan failure<br />

• High duct static pressure<br />

• Low mixed air temperature<br />

All alarms must be resettable at the operator display.<br />

First, set the program properties as shown in Figure 119 on page 129.<br />

128 CNT-APG001-EN

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