Trane VUV Installation, Operation And Maintenance Manual page 105

Table 51. Tracer® ZN520 test sequence
Step
1(a)
1. Off
(b)
2. Fan high
(c)
3.
4. Fan low
5. Main open
6. Main close, EH1 on
7. Aux. open
8. Aux. close, damper open
9. Damper close
10. Generic/baseboard heat
energized
(e)
11. Exit
(a) Upon entering manual output test mode, the controller turns off all fan and electric heat outputs and drives.
(b) At the beginning of Step 2, the controller attempts to clear all diagnostics.
(c) The low fan speed output energizes at
(d) If the unit is configured for a 1- or 2-speed fan, and BOP2 is configured for an exhaust fan, the exhaust fan output energizes on
medium speed.
(e) After Step 10, the test sequence performs an exit. This initiates a reset and attempts to return the controller to normal operation.
Translating Multiple Diagnostics
The controller senses and records each diagnostic
independently of other diagnostics. It is possible to have
multiple diagnostics present simultaneously. The diagnostics
are reported in the order they occur.
Possible diagnostics include:
• Low coil temperature detection
• Condensate overflow
• Low air flow—fan status
• Discharge air temp limit
• Space temperature failure
• Entering water temp failure
• Discharge air temp failure
• Outdoor air temp failure
1
• Local setpoint failure
1
• Local fan mode failure
1
• CO sensor failure
2
1
• Generic AIP failure
1
• Humidity input failure
• Defrosting compressor lockout
2
• Maintenance required
• Invalid Unit Configuration
• Generic temperature failure
• Discharge air low limit
Resetting Diagnostics
There are seven ways to reset unit diagnostics:
• Automatically by the controller
• By initiating a manual output test at the controller (Tracer®
ZN520 only)
1
Non-latching diagnostics automatically reset when the input is present and valid.
2
Does not apply to the UC400-B/Symbio™ 400-Bcontroller.
UV-SVX005G-EN
Fan Main Valve
J1-1 J1-2 J1-3
Off Off Off
High Off Off
Off Off
Off Off Low
High Off Off
High Off Off
High
(d)
Exh Off
EH1 on
High Off Off
High Off Off
High Off Off
Exit
Step 3. If the unit is configured for a 1-speed fan, the fan remains on high speed at
1
1
1
1
2
2
Diagnostics and Troubleshooting
Electric Heat or Aux. Fresh Air
Valve Damper
J1-5 J1-6 J1-9
On
Off Off
EH: off
Off Off Off
Off Off Off
Off Off Off
On Off Off
Off On On
Off Off On
Off
Off Off
EH1 off
Off Off Off
Off Off Off
• By cycling power to the controller
• By using a building automation system
• By using the Rover service tool
• By using any other communicating device able to access
the controller's diagnostic reset input (Tracer® ZN520
only)
• By cycling the fan switch from off to any speed setting
(Tracer® ZN520 only)
Automatic Reset by the Controller
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 low temperature 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 possible methods of resetting diagnostics are
described in the sections that follow.
Generic/Baseboard Heat
J1-10 J1-11 J1-12
aux: on Off On
Off Off Off
Off Off Off
Off Off Off
Off Off Off
Off Off Off
Off Off Off
On
On Off
EH2 on
Off Off On
Off Off Off
Step 3.
Step 7. The exhaust fan output is shared with
TB4-1
Off
Off
Off
Off
Off
Off
Off
Off
Off
On
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