SMA5005 & SMA5015 MANUAL
MANUAL # 5005-2040-000-F UPDATED: 6/1/2021
Use the following relationships to calculate Drive dissipation:
1)
Pd = Im x Vb (watts)
Where: Pd = Total watts delivered from bus
Im = Motor current
Vb = Bus voltage
2)
Pm = Im x Vm (watts)
Where: Pm = Total power (watts) dissipated in motor
Vm = Motor voltage
3)
Pa = Im x Vb - Im x Vm
Where: Pa = Total watts dissipated at Drive
From the above relationship, it can be surmised that the worst case dissipation occurs when the
Drive has to deliver a high continuous current at a low motor speed, i.e., less motor BEMF and
more current. For some applications, a power resistor can be added in series with the motor thus
shifting some of the power dissipation from the Drive to the resistor.
