Schneider Electric Lexium 17S Series - Manual (Page 140)

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Example Regen Resistor Power Dissipation Calculation, continued
Example Step 4 Compare the energy in each deceleration with the energy required to turn on the
Regen circuit (that is, the energy absorbed by the internal capacitors).
As specified in the Drive Energy Absorption Capability table, the MHDS1028N00
drive at 480 Vac can absorb 23 joules without turning on the Regen resistor circuit.
Deceleration 1: 493 joules > 23 joules
Deceleration 2: 20 joules < 23 joules (disregard this segment in the remaining
steps)
Deceleration 3: 652 joules > 23 joules
Example Step 5 Calculate dissipated energy as follows:
Deceleration 1: E = 493 – 23 = 470 joules
Deceleration 3: E = 652 – 23 = 629 joules
Example Step 6 Calculate the pulse power as follows:
Deceleration 1: P
pulse
= 470 joules / 0.5 seconds = 940 watts
Deceleration 3: P
pulse
= 629 joules / 0.5 seconds = 1258 watts
Example Step 7 Calculate continuous power as follows:
P
continuous
= (470 joules + 629 joules) / 4.75 seconds = 231 watts
Continued on next page