Installation and Maintenance Manual
Table Of Contents
- Warnings, Cautions and Notices
- Model Number Descriptions
- General Information
- ECM Application Notes
- Dimensions and Weights
- Receiving and Handling
- Pre-Installation
- Installation—Mechanical
- Installation—Piping
- Installation—Sensors
- Installation—Electrical
- ECM Overview and Setup
- Time Clock
- Wired Controllers—Communication Wiring
- Pre-Start
- Startup
- Tracer ZN520 Unit Startup
- Tracer UC400 Unit Startup
- General Information
- Fan Mode Switch Operation
- Tracer ZN520 Operation
- UC400 Controller Operation
- Tracer ZN520 Sequence of Operation
- UC400 Sequence of Operation
- Power-up Sequence (UC400)
- Random Start (UC400)
- Occupancy Modes (UC400)
- Timed Override Control (UC400)
- Zone Temperature Control (UC400)
- Discharge Air Tempering (UC400)
- Heating or Cooling Mode (UC400)
- Entering Water Temperature Sampling Function (UC400)
- Fan Operation (UC400)
- Exhaust Control (UC400)
- Valve Operation (UC400)
- Modulating Outdoor/Return Air Damper (UC400)
- Two-position Control Of A Modulating Outdoor Air Damper (UC400)
- Electric Heat Operation (UC400)
- Dehumidification Operation (UC400)
- Peer-to-peer Communication (UC400)
- Unit Protection Strategies (UC400)
- Maintenance
- Diagnostics
- Replacing ECM Components

Diagnostics
96 UV-SVN03F-EN
Troubleshooting (Wireless
Controls)
Locations of LEDs, Test button, Test Symbols,
and Error Codes
The receiver for all models has four LEDs: LED1, LED2,
LED3, and LED5. Figure 65 shows their locations.
Note: To view LEDs on a flush mount receiver on a fan-
coil unit, the front panel of the unit must be
removed.
The sensor for model WZS have four LEDs: LED1, LED2,
LED3, and LED5. The sensor for model WDS has test
symbols and error codes that appear on the display. All
three sensor models have a Test button. Figure 66 shows
their locations.
Space
temperature
failure
(a)
Invalid or missing
value for zone
temperature.
• Discharge air
temperature control
runs
•Unit shuts OFF if both
space temperature
and discharge air
temperature fail
Automatic
Entering
water temp
failure
Invalid or missing
value for zone
temperature.
•Fan Unaffected
(enabled)
•Valves Unaffected
• Outdoor air damper
Unaffected
• DX/electric heat
Unaffected
Automatic
Discharge air
temp low
limit
Discharge air
temperature has
fallen below the
Discharge Air
Temperature Low
Limit.
•Fan OFF
•Valves Open
• Outdoor air damper
Closed
• DX/electric heat OFF
Smart reset/
manual
Discharge air
temp
failure
(a)
Invalid or missing
value for discharge
air temperature.
• Simplified zone
control algorithm runs
• Unit shuts OFF if zone
temperature fails
Automatic
Outdoor air
temp failure
Invalid or missing
value for outdoor air
temperature.
•Fan Unaffected
•Valved Unaffected
• Outdoor air damper
Minimum
Position
• DX cooling/electric
heat unaffected
Automatic
Humidity
input failure
Invalid or missing
value for relative
humidity.
•Fan Unaffected
•Valves Unaffected
• Outdoor air damper
Unaffected
• DX cooling/electric
heat Unaffected
Automatic
CO
2
sensor
failure
Invalid or missing
value for CO
2
.
•Fan Unaffected
•Valves Unaffected
• Outdoor air damper
Unaffected
• DX cooling/electric
heat Unaffected
Informational
Generic AIP
failure
Invalid or missing
value for generic
analog input.
•Fan Unaffected
•Valves Unaffected
• Outdoor air damper
Unaffected
• DX cooling/electric
heat Unaffected
Informational
Local fan
mode failure
Invalid or missing
fan-speed switch
(reverts to default
fan speed).
•Fan Unaffected
•Valves Unaffected
• Outdoor air damper
Unaffected
• DX cooling/electric
heat Unaffected
Automatic
Local
setpoint
failure
Invalid or missing
value for zone
temperature
setpoint (reverts to
default setpoint).
•Fan Unaffected
•Valves Unaffected
• Outdoor air damper
Unaffected
• DX cooling/electric
heat Unaffected
Automatic
(a) For detailed information about zone temperature control methods, refer
to “Zone Temperature Control (UC400),” p. 81.
Table 34. UC4000 diagnostics (continued)
Diagnostic Probable Cause Consequences
Diagnostic
Type
Figure 65. LED locations on the receiver
LED1
LED2
LED3
LED5
UV-SVN03_.book Page 96 Thursday, January 24, 2013 5:27 PM