Emerson Unidrive M201 Installation Manual page 15

Typical short term overload limits
The maximum percentage overload limit changes depending on the selected motor. Variations in
motor rated current, motor power factor and motor leakage inductance all result in changes in the
maximum possible overload. Typical values are shown in the table below:
Table 2-6 Typical overload limits
Operating mode
Normal Duty overload with motor rated
current = drive rated current
Heavy Duty overload with motor rated
current = drive rated current (size 8 and
below)
Heavy Duty overload with motor rated
current = drive rated current (size 9 and 10)
Generally the drive rated current is higher than the matching motor rated current allowing a higher
level of overload than the default setting.
The time allowed in the overload region is proportionally reduced at very low output frequency on
some drive ratings.
The maximum overload level which can be attained is independent of the speed.
NOTE
Output current
The continuous output current ratings given on the rating label are for maximum 40 °C (104 °F),
1000 m altitude and 3 kHz switching frequency (except where shown). Derating is required for higher
switching frequencies, ambient temperatures >40 °C (104 °F) and higher altitude. For derating
information, refer to Chapter 5 Technical data on page 88
Input current
The input current is affected by the supply voltage and impedance. The input current given on the
rating label is the typical input current and is stated for a balanced supply.
Unidrive M / HS Frame 7 to 10 Power Installation Guide
Issue Number: 5
RFC from cold RFC from 100 %
110 % for 165 s 110 % for 9 s
200 % for 28 s 200 % for 3 s
175 % for 42 s 175 % for 5 s
Open loop Open loop
from cold from 100 %
110 % for 165 s 110 % for 9 s
150 % for 60 s 150 % for 7 s
150 % for 60 s 150 % for 7 s
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