Input Over-voltage

What does E15 mean?

This fault is triggered when the inverter detects an excessive input voltage from the power supply, specifically during its idle (Stop) mode for a prolonged period (100 seconds). The inverter enters a fault state to protect its internal components from damage due to sustained high voltage.

• Input AC power supply voltage consistently above the inverter's maximum specified input voltage (e.g., >480V for 400V class).
• Voltage spikes or surges on the incoming power line, exceeding the inverter's transient voltage rating.
• Incorrect selection of inverter voltage class (e.g., 200V class inverter connected to 400V supply).
• Malfunction of the inverter's input voltage sensing circuit, leading to an erroneous high voltage reading.
• Over-sized distribution transformer providing excessive output voltage due to light loading or poor regulation.

Click steps to track your progress.

1. 1

   Measure the input AC voltage across inverter terminals L1, L2, L3 using a multimeter to confirm it is within the specified operating range (e.g., 380-480V for a 400V unit).

2. 2

   Monitor the input voltage over time to detect intermittent surges or sustained high voltage conditions using a logging multimeter or power quality analyzer.

3. 3

   Verify that the installed inverter's rated input voltage matches the facility's power supply voltage (e.g., a 400V class inverter for a 400V supply).

4. 4

   Check for loose or corroded connections at the inverter's input terminals L1, L2, L3 and in the upstream power distribution.

5. 5

   If sustained high input voltage is confirmed, consult with facility maintenance to investigate the upstream power supply and distribution transformer output.