Trane ZN.520 manual Troubleshooting, Yellow Comm LED, Red Service LED, Black Service Push Button

Troubleshooting

Important! When viewing the Tracer ZN.520 through the Rover service tool, it is important that the version be up-to-date. To help ensure that your version is the most recent, contact you local Trane sales representative or service center.

The Service push button, located at the bottom center of the control- ler, can be used to install the Trac- er™ ZN.520 Unit Controller in a communication network. Refer to the Rover and Tracer Summit product literature for more infor- mation.

Yellow Comm LED

The yellow Comm LED blinks at the rate the controller receives communication. The yellow LED does not blink when the controller is transmitting communication data.

Table 25: Yellow comm LED activity

Led Operation

Red Service LED

Table 23: Red service LED activity

Red LED

Description

activity

LED is OFF continuously

after power is Normal operation. applied to the

controller.

LED is ON

continuously,

Someone is pressing the

even when

Service push button or

power is first

the controller has failed.

applied to the controller.

Un-install (normal controller mode). Use

Rover service tool to

LED flashes

restore the unit to

about once

normal operation. Refer

every second.

to the Rover product literature for more information.

Black Service Push

Button

Note: If the Service push button is held down for more than 15 seconds, the Tracer™ ZN.520 Unit Controller will un- install itself from the ICS communication network and shut down all unit operation. This mode is indicated by the red Service LED flashing once every second. See the Red Service LED section. Use Rover service tool to restore the unit to normal operation.

Figure 25: Black service button

Green Status LED

The green LED normally indicates whether or not the controller is powered on (24 VAC).

Table 24: Green status LED activity

Green LED	Description
activity
LED is ON	Power ON (normal
continuously.	operation).
LED blinks (1 blink	The controller is in
per second).	manual output test
	mode.
	No diagnostics
	present.
LED blinks (2	The controller is in
blinks per second).	manual output test
	mode.
	One or more
	diagnostics are
	present.
LED blinks (1/4	Wink mode.
second on, 1/4
second off for 10
seconds).
LED OFF.	Power is off.
	Controller failure.
	Test button is
	pressed.

Yellow LED	Description
activity
LED OFF	The controller is not
continuously.	detecting any
	communication. (Normal
	for standalone
	applications.)
LED blinks or	The controller detects
flickers.	communication. (Normal
	for communicating
	applications, including
	data sharing.)
LED ON	Abnormal condition or
continuously.	extremely high traffic on
	the link.

Manual Output Test

The test sequence verifies output and end device operation. The manual output test can be conduct- ed to verify output wiring and actu- ator operation, without using the Rover service tool, by pressing the test button.

Figure 26: Blue test button

Many service calls are initiated due to unit diagnostics, so the test se- quence attempts to clear unit diag- nostics and restore normal unit operation prior to testing the out- puts. If the diagnostics remain after an attempt to clear diagnostics, the status LED lights in a two-blinkpat- tern, indicating the diagnostic con- dition is still present.

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