The price of an AC variable speed drive (inverter) is related directly to its rated power output and duty cycle.  It stands to reason that the lighter the duty cycle the less stress there is on the inverter.

By publishing a wider range of duty cycles for its new FR-A800, Mitsubishi Electric UK offers users the chances to make significant cost savings.  Where a smaller frame size is selected there may be additional savings in cabinet size and conductor rating.

Rated current and four different overload capacity ratings (SLD rating (super light duty), LD rating (light duty), ND rating (normal duty), HD rating (heavy duty)) can be selected with parameters in the drive. The optimum inverter can be selected to suit the application, and by selecting an inverter with SLD or LD rating, equipment size can be reduced when compared with the FR-A700 series. The HD rating is best suited for applications requiring low speed and high torque.

If using an inverter with capacity of 75K or higher, or motor with capacity of 75 kW or higher, always select and install the inverter based on the capacity of the motor with DC reactor.

Overload current  ratings*

SLD= Super light duty for 110% 60 s, 120% 3 s (inverse-time characteristics) at surrounding air temperature 40°C

LD= Light duty for 120% 60 s, 150% 3 s (inverse-time characteristics) at surrounding air temperature 50°C

ND= Normal duty for 150% 60 s, 200% 3 s (inverse-time characteristics) at surrounding air temperature 50°C

HD= Heavy duty for 200% 60 s, 250% 3 s (inverse-time characteristics) at surrounding air temperature 50°C

999 Inverters offers a wide range of Mitsubishi Electric UK drives from stock at discounted prices