Easy 3L Power Block logs are recording a temperature out-of-tolerance alarm or over temperature

Issue:
During normal operation with a load between 50 to 100% load and due to low fan speed or other causes, it is possible to get the temperature out of tolerance alarms
Environment:
Startup phase, FSR testing UPS with load, HVAC design and implementation, Break Fix, Temperature alarms activated in the UPS or UPS room. Normal operating status with loads. Loads from 40% to 100%, typically 50% to 75% if the fan speed is low.
Possible Cause:

• The power block inverter heatsink temperature is out of tolerance
• The power block PFC heatsink temperature is out of tolerance
• The temperature sensor could be faulty inside the power block.

These alarms can be pre-activated for the following reasons or a combination of reasons:

• The UPS has two ambient temperature sensors. The first is installed on the back of the front panel, and the second is installed on the bypass block control board as a backup.
• If the temperature is over 35℃, the ambient temperature sensors monitor the ambient temperature and control the cooling fan's speed.
• The placement of the HVAC system and back pressure affect the UPS fans' ability to pull air from the front.

Resolution:

• Check for airflow restrictions in front of each power block.
• Verify all fans are working and pushing air toward the Power Blocks.
• As a contributing factor, check the room's ambient temperature and load percentage.
• Verify the HVAC room's back pressure condition as the main contributor or as an additional contributor.
• Check the UPS exhaust sections for restrictions and turbulent airflow.

Caution: If the ambient temperature in the UPS room crosses 40°C, the UPS load will shift to bypass operation.

Note: If the above conditions meet, then an FSR visit is required to check the UPS parameters and Event logs. Please contact Schneider Electric.

Released for: Schneider Electric India