Diagnosing operational problems
CNT-SVX12C-EN
89
Table 30. Fan does not energize
Probable cause
Explanation
Unit wiring
The wiring between the controller outputs and the fan relays and contacts must be
present and correct for normal fan operation. Refer to applicable wiring diagram.
Failed end device
The fan motor and relay must be checked to ensure proper operation
Random start
observed
After power-up, the controller always observes a random start from 0 to 25 seconds. The
controller remains off until the random start time expires.
Power-up control-wait
If power-up control-wait is enabled (non-zero time), the controller remains off until one of
two conditions occurs:
1) The controller exits power-up control-wait once it receives communicated information.
2) The controller exits power-up control-wait once the power-up control-wait time expires.
Cycling fan operation
If configured to cycle with capacity, normally the fan cycles off with heating or cooling.
The heating/cooling sources cycle on or off periodically with the fan to provide varying
amounts of capacity to the zone.
Unoccupied operation
Even if the controller is configured for continuous fan operation, the fan normally cycles
with capacity during unoccupied mode. While unoccupied, the fan cycles on or off with
heating/cooling to provide varying amounts of heating or cooling to the space.
Fan mode off
If a local fan mode switch determines the fan operation, the off position controls the fan
off.
Requested mode off
You can communicate a desired operating mode (such as off, heat, and cool) to the con-
troller. If off is communicated to the controller, the unit controls the fan off. There is no
heating or cooling.
Diagnostic present
For information about diagnostics, see Table 28 on page 79.
No power to the con-
troller
If the controller does not have power, the unit fan does not operate. For the Tracer ZN517
controller to operate normally, it must have an input voltage of 24 Vac. If the green LED is
off continuously, the controller does not have sufficient power or has failed.
Unit configuration
The controller must be properly configured based on the actual installed end devices and
application. If the unit configuration does not match the actual end device, the valves may
not work correctly.
Manual output test
The controller includes a manual output test sequence you can use to verify output oper-
ation and associated output wiring. However, based on the current step in the test
sequence, the unit fan may not be on. Refer to the “Manual output test” on page 74.
Содержание Tracer ZN517
Страница 1: ...CNT SVX12C EN Installation and Operation Tracer ZN517 Unitary Controller...
Страница 2: ......
Страница 3: ...Installation and Operation Tracer ZN517 Unitary Controller CNT SVX12C EN April 2005...
Страница 4: ......
Страница 12: ...Table of contents vi CNT SVX12C EN...
Страница 38: ...Chapter 4 Sequence of operations for the 2 heat 2 cool configuration 26 CNT SVX12C EN...
Страница 56: ...Chapter 6 Sequence of operations for the 4 cool configuration 44 CNT SVX12C EN...
Страница 92: ...Chapter 10 Status indicators for operation and communication 80 CNT SVX12C EN...
Страница 104: ...Chapter 12 Troubleshooting 92 CNT SVX12C EN...
Страница 110: ...Index 98 CNT SVX12C EN...