⋅ IM ≤ the rated current of AC motor drive a

Error! Reference source not found. Error! Reference source not found.VFD-S Series

2.3 When it is running continuously

The requirement of load capacity should be less than the capacity of the AC motor drive(kVA)

The requirement of load capacity is

k ⋅ PM ≤ the _ capacity _ of _ AC _ motor _ drive(kVA) η ⋅ cosϕ

The motor capacity should be less than the capacity of AC motor drive

k ⋅ 3 ⋅VM ⋅ IM ⋅10−3 ≤ the _ capacity_ of _ AC _ motor _ drive(kVA)

The current should be less than the rated current of AC motor drive(A)

k ⋅ IM ≤ the _ rated _ current _ of _ AC _ motor _ drive( A)

Symbol explanation

PC1 kS

nT nS

:Motor shaft output for load (kW)

:Motor efficiency (normally, approx. 0.85)

:Motor power factor (normally, approx. 0.75)

:Motor rated voltage (V)

:Motor rated current (A), for commercial power

:Correction factor calculated from current distortion factor (1.05-1.1, depending on PWM method)

:Continuous motor capacity (kVA)

:Starting current/rated current of motor

:Number of motors in parallel

:Number of simultaneously started motors

:Total inertia (GD2) calculated back to motor shaft (kg m2)

:Load torque

:Motor acceleration time

:Motor speed

Revision August 2006, SE08, SW V2.61

C-3