Abnormal Temperature (Main Circuit)

What does E21. mean?

This fault occurs when the temperature in the inverter's main circuit exceeds a specified maximum value. This is typically caused by high ambient temperatures, insufficient ventilation, or clogged cooling fins, leading to thermal stress on internal components. Prolonged exposure to abnormal temperatures can significantly shorten the inverter's lifespan and lead to irreversible damage.

Additional Steps

Steps 1–2 are listed in Priority Fix.

1. 3

   Check if the cooling fan is stopped; if so, set parameter b092 to 'Always enabled' (00) and verify power supply to the fan.

2. 4

   Inspect the cooling fins for any dust accumulation or clogging and clean them thoroughly.