Allen-Bradley DC-UPS Manual page 37

Single flash on the "Error" Light-emitting Diode (LED)
"Error" Light-emitting Diode (LED) is solid on
DC-UPS did not buffer
DC-UPS stopped buffering
DC-UPS stopped buffering for 1 s
DC-UPS constantly switches between power supply mode and battery mode
Troubleshooting
The following guidelines provide instructions for fixing the most common
failures and problems. Always start with the most likely and easiest to check
condition. Some of the suggestions may require special safety precautions. See
Important User Information
Symptom
Rockwell Automation Publication 1606-RM008A-EN-P - November 2021
first.
Explanation / Action
• Check input voltage. The input voltage must be at least 1V higher than the
selected buffer voltage and smaller than 30V.
• Check correct wiring between the battery and the DC-UPS
• Check battery fuse. Is the battery fuse inserted or blown?
• Check battery voltage (must be between 14.8V and 30V)
• Check battery polarity
• Inhibit input was set.
• Battery did not have enough time to get charged and the battery voltage is still
below the deep-discharge protection level.
• Deep discharge protection stopped buffering. Use a larger battery, or allow
sufficient time for charging the battery.
• End of service life of the battery
• Battery did not have enough time to be charged.
• Inhibit input was activated
• Buffer time limiter stopped buffering. Change the settings of the buffer time
limiter on the front of the unit.
• Exceeds temperature range
• Center-tap connection opens in buffer mode
• Center-tap connection problems
• The supplying source on the input is too small and cannot deliver sufficient
current. Use a larger power supply or reduce the output load.
• The output voltage of the power supply dips to a too low value. The input voltage
must always be at least 1V higher than the selected buffer voltage and smaller
than 30V. Increase the output voltage of the power supply
• Exceeds voltage drops on wires. Increase the output voltage of the power supply
or increase the wires cross section from the power supply to the DC-UPS.
DC-UPS - 24V, 20 A, 480 W Reference Manual
37