1. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// Inverter FR-A740-7.5k M Gearbox Pully Load 300 kg Lifting distance = 30 m i = 1 : 4 Period of cycle = 120sec. Lowering speed 3 m / s How to calculate brake duty?

2. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// Load M L = 300 kg Lifting distance h = 30 m Lowering speed v = 3 m / s Efficiency  Mechanism = 98%  Gearbox = 95%  Motor = 92% Period of cycle t total = 10 min. Needed technical data from the application

3. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// W pot. = M L X g x h = 300kg X 9,81m/s² x 30m M L = 300 kg ( Load ) g = 9,81 m / s² ( gravity ) h = 30 m ( lifting distance ) Calculation Calculation of the Potential Energy The potential energy which is stored in the raised load. Is now given back to the brake resistors in time t Brake.

4. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// Calculation of Braking Time : Within 10 s, the entire potential energy will be feed back into the brake resistors. Calculation of the Brake power : Brake power if lowering speed is slow

5. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// Calculation of Braking Time : Within 0,5 s, the entire potential energy will be feed back into the brake resistors. Calculation of the Brake power : Brake power if lowering speed is high

6. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// Duty cycle [%] Every option which is working with a brake resistor has a duty cycle. With this value you can calculate the shortest time to the next allowed brake duty. Duty cycle

7. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// Ed in case of A700 and external brake Resistor Jumper PX->PRonly PR 100% torque, 6% ED 100% torque, 10% ED

8. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// Duty cycle In case of slow lowering speed Ed fits Period of cycle = 120sec. 10s

9. Industrial Automation Mitsubishi Electric – Inverter basics /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// INVERTER /// But brake power is to high! Braking capability of ABRH series