Period 1
Period 2
Period 3
Time
For vertical load
Torque
Speed
Average regenerative energy [W]
1 cycle time [s]
(P1+P2 … +Pi)[J]
=
Note 1. For Speed, the forward rotation direction is indicated as positive. For Torque, the torque in the for-
ward rotation direction is indicated as positive.
Note 2. Calculate a braking torque according to Inverter Capacity Selection in the Motor Capacity Selection
section.
Braking Resistor Selection
Select a braking resistor from the required braking resistance and the average regenerative energy
obtained in this calculation.
• Required braking resistance ≥ Resistance of braking resistor
≥ Min. connection resistance of in-
verter
• Average regenerative energy ≤ Resistance capacity of braking resistor
Note 1. Connecting a braking resistor whose resistance is less than the minimum connection resistance val-
ue of the inverter results in damage to the internal braking transistor. If the required braking resist-
ance is less than the minimum connection resistance, change the inverter to one having a larger ca-
pacity and ensure that the required braking resistance is not less than the minimum connection re-
sistance.
Note 2. Make allowance for the resistance capacity of the braking resistor. Select a braking resistor whose
capacity is at least 20% larger than the calculated value. Otherwise, it may be overheated.
Appendix
A-17
M1 Series Standard Type User's Manual (I669)
A-4 Overview of Inverter Selection
A
A-4-3 Overview of Braking Resistor Selection