Trane LO - Manual (Page 51)

UNT-IOM-6 51
Tracer
®
ZN.010
and ZN.510
Cycling Power to the
Controller
There are four ways in which diagnostics are reset:
1. Automatic reset by the controller
2. By initiating a manual output test at the controller
3. By cycling power to the controller
4. Through Rover™, Trane’s service tool
The controller includes an automatic diagnostic reset function which
attempts to automatically restore the unit when a low temperature
diagnostic occurs.
Note: The controller implements the automatic diagnostic reset
function only once every 24 hours. For the controller to increment the
24 hour timer, you must maintain power to the controller. Cycling
power resets all timers and counters.
After the controller detects the first special diagnostic, the unit waits
30 minutes before invoking the automatic diagnostic reset function.
The automatic diagnostic reset function clears the special diagnostic
and attempts to restore the controller to normal operation. The
controller resumes normal operation until another diagnostic occurs.
Note: The automatic diagnostic reset function does not operate during
the manual output test sequence.
If a special diagnostic occurs within 24 hours after an automatic
diagnostic reset, the controller must be manually reset. Other pos-
sible methods of resetting diagnostics are described in the sections
that follow.
Use the controller’s Test button during installation or for troubleshoot-
ing to verify proper end device operation. Press the Test button to
exercise all outputs in a predefined sequence, the first of which will
attempt to reset the controller diagnostics if any are present. See
Table 13 on page 49 for more information about the manual output
test.
After removing and reapplying the 24 VAC power from the board, the
unit cycles through a power-up sequence. By default, the controller
attempts to reset all diagnostics at power-up. Diagnostics present at
power-up and those that occur after power-up are handled according
to Table 14 on page 50.
Resetting
Diagnostics
Automatic Reset by
the Controller
Manual Output Test