This FAQ has been written for NEAL (North East Africa and Levant) region. If you are looking for information for another region, please select the correct country from the top-left dropdown in the page and 'Navigate to Browse FAQs' in the Support menu.
Issue: The UPS reports P.11 or DC Bus Voltage Low - event 128/129
Product Line: Smart-UPS SRT 8-10kVA Models
Resolution:
Clear the Alarm. Turn the output ON again. If the problem persists, Brain dead the UPS. If the alarm reoccurs, perform a UPS Firmware upgrade to the latest 04.7 revision that addressed these issues. For complete upgrade instructions please refer to FA164737.
Release Notes (UPS 04.7):
========================
1. Improved system performance of transitions between Online and Bypass operation modes.
2. Improved system behaviour for three phase input configurations to reduce transitions to battery under certain input feed conditions.
3. Improved system behaviour to eliminate false detection of DC bus under voltage alarm under certain conditions.
4. Improved system handling for certain AC input conditions during system start-up.
Product Line: Smart-UPS SRT 8-10kVA Models
Resolution:
Clear the Alarm. Turn the output ON again. If the problem persists, Brain dead the UPS. If the alarm reoccurs, perform a UPS Firmware upgrade to the latest 04.7 revision that addressed these issues. For complete upgrade instructions please refer to FA164737.
Release Notes (UPS 04.7):
========================
1. Improved system performance of transitions between Online and Bypass operation modes.
2. Improved system behaviour for three phase input configurations to reduce transitions to battery under certain input feed conditions.
3. Improved system behaviour to eliminate false detection of DC bus under voltage alarm under certain conditions.
4. Improved system handling for certain AC input conditions during system start-up.
Released for:Schneider Electric Egypt and North East Africa
