Tait TB8100, Service Manual

Page: 229 / 306

TB8100 Service Manual Power Management Unit Fault Finding 229
© Tait Electronics Limited September 2006
Task 5 —
Additional Service
Kit Tests
You can also use the Service Kit to perform some additional tests on the
PMU. The Control Tests form (Diagnose > Power Management > Control
Tests) allows you to carry out the following checks:
■
Simulating mains failure.
■
Testing the fan.
■
Testing the PMU fault (red) LED.
■
Testing the auxiliary power output.
The Supply Tests form (Diagnose > Power Management > Supply Tests)
provides the following additional information about the PMU:
■
Heatsink temperatures for AC and DC modules.
■
Battery voltage.
■
Output voltage and current.
Refer to the Service Kit documentation for more details.
13.7 Auxiliary Power Supply Board
The optional auxiliary power supply board is a DC–DC converter which
takes the 28VDC output from the DC or AC converter board and converts
it to the required 12/24/48VDC (nominal; depending on the model of
board). This board is disabled by default, and only operates when it is
switched on by the microprocessor.
1. Set up the test equipment as shown in Figure 13.2 on page 222 .
2. Run the Service Kit and select Diagnose > Power Management >
Control Tests. Follow the instructions in the online Help to toggle
the supply on/off.
3. If necessary, measure the voltage from the auxiliary DC output
connector (as shown in
Figure 13.8 on page 235 ) and check that it is
as listed in Table 13.3 . The toggle function turns the supply on for a
few seconds, but this is long enough to give an output which can be
measured.
4. If the Service Kit test fails, or if the output voltage is wrong or not
present, replace the auxiliary power supply board.
Table 13.3 Auxiliary power supply output voltages
Model Float Voltage (no load)
12V 13.65VDC ±2%
24V 27.3VDC ±2%
48V 54.6VDC ±2%