1. The inverter turns off after a few seconds

● Probably the inverter is overloaded , infact in this case it goes in a protection mode after few seconds . To turn it back on, press ENABLE (or, in very old models without ENABLE key, switch off the inverter for few seconds and then switch it on again).
● Note: when calculating the power required by load, consider the power factor PF of the load. Consider also the crest factor of any non-linear loads (i.e. power supplies is missing the PFC stadium).

2. The inverter turns off sometimes during operation

Probably the load is not constant and some times it exceeds the maximum capacity of the inverter, which goes in overload protection. It is recommended to verify not only the static power, but also the dynamic power of the load (eg. big engines or transformers).

3. FCD led is on (red)

Each of the internal fans is supervised by the FCD device (Fan Control Device).
● FCD Led is on red→ the relative fan works at less than 70% of the rated fan speed, try cleaning the fan with compressed air to remove any dust. If the problem persists, the fan must be replaced.
● FCD Led is red blinking→ the relative fan works at less than 30% of the rated speed, or is stopped. The fan is to be replaced, unless there is an obstacle that stops the fan.

4. The drive is noisy

The inverter operates at the switching frequency 20kHz, and produces an output sine wave at 50 or 60Hz. The human auditory bandwidth is equal to 20Hz ÷ 20kHz, and so it is normal that the inverter appears relatively noisy.

5. The inverter is very heavy

The inverter operates at the switching frequency 20kHz, and produces an output sine wave at 50 or 60Hz. The human auditory bandwidth is equal to 20Hz ÷ 20kHz, and so it is normal that the inverter appears relatively noisy.