Carrier EACAAXCC0014 Installation And Operation Manual page 29

CHECKING THE POWER SUPPLY
If the output light remains out with the collector cells removed from the
cabinet, the power supply is defective. Specific problems on the power tray
assembly can be isolated by using a multimeter and high voltage probe to
check the output voltages.
To check the secondary circuit, a high voltage meter is required. See the
section entitled RECOMMENDED SERVICE TOOLS. To check for proper
operation, it is imperative that the procedure be followed as outlined below:
1. Make sure the furnace blower is operating, the control switch is on and
input voltage is 120 volts, 60 Hz.
2. Remove front door assembly panel.
3. Remove power pack access cover.
4. Check the high voltage contact board assembly(s) for damage or carbon
tracking.
5. Make connections from the high voltage probe to the multimeter in
accordance with the operatoCs manual. The meter should be set for
reading DC voltage on the 20 volt full scale.
6. Attach the high voltage probe ground lead to the cabinet. While
depressing the safety switch lever, touch the ionizer wire support bar
with end of the high voltage probe (Figure 10). The meter reading should
be 6.2 kVDC ± .2 kVDC,
7. If no voltage is measured, remove the first cell and check the second cell.
The meter should read 6.2 kVDC ± .2 kVDC.
8. If proper voltage is measured, the first cell is shorted. Refer to Table 1, on
page 12.
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