Maintenance/Troubleshooting - Power problems
a - 14 • • • Intelli-FLEX II product guide
3. If the DC voltage is less than 18.0 VDC, find the cause and correct it. Check
output from the central power supply. It should read at least 24 volts. Is there
too much voltage drop in the line to the processor?
System shutdown
The system will operate with a 12 volt low (Power fail) supervision alarm, (11.0
VDC) but will shut down if the DC voltage at VDD drops below 8.0 VDC. The
system will come back on line when DC voltage rises to 11.0 VDC. The 12 volt low
supervision alarm will clear when the converter output voltage rises to 10.5 VDC.
1. If the DC voltage input to the processor at TB-1 terminals 3 and 4 is greater
than 11.5 VDC, and the processor does not operate, there is probably a
problem with the processor. Be sure to investigate other symptoms in this
troubleshooting section before concluding the processor board has failed.
AC operation with battery backup
An individual processor may be powered from 115 VAC by using the DC power/
float charger and battery provided, and by applying the +12 VDC to TB1 pins 3
(—) and 4 (+).
If the backup battery has been fully discharged, it may take some time after AC
power is restored to charge the battery to a sufficient voltage to operate the
Intelli-FLEX II processor. When this occurs, the power fail shutdown will be in
effect until the battery voltage reaches approximately 11 VDC. It may take a few
minutes for the voltage on a fully discharged good battery to reach 11 volts.
A defective battery may never charge to reach 11 volts. If the 0.8 amp-hour battery
that is supplied with the Intelli-FLEX II processor does not reach 11 volts after
about 10 minutes of charging, it is defective and should be replaced. A defective
battery that is fully discharged may quickly charge to a voltage of 11 volts, but not
hold a charge. Be sure to replace the backup battery at the recommended
intervals suggested by the battery manufacturer for your local environment. Avoid
placing gell cell batteries in extreme temperature environments if possible.
If a known good battery fails to charge to at least 11 VDC after about 10 minutes
the DC Float charger module should be suspect.