Instruction Manual

Application Notes D-3
[Motor OL Hertz] defines the frequency where motor overload capacity
derate should begin. The motor overload capacity is reduced when
operating below [Motor OL Hertz]. For all settings of [Motor OL Hertz]
other than zero, the overload capacity is reduced to 70% at an output
frequency of zero.
[Motor NP FLA] is multiplied by [Motor OL Factor] to select the rated current
for the motor thermal overload. This can be used to raise or lower the level of
current that will cause the motor thermal overload to trip. The effective overload
factor is a combination of [Motor OL Hertz] and [Motor OL Factor].
Motor Overload Curve
100 125 150 175 200 225 250
Full Load Amps (%)
Trip Time (Sec)
Cold
Hot
10
100
1000
10000
100000
Changing Overload Hz
0102030405060708090100
% of Base Speed
Continuous Rating
OL Hz = 10
OL Hz = 25
OL Hz = 50
0
20
40
60
80
100
120
Changing Overload Factor
0102030405060708090100
% of Base Speed
Continuous Rating
OL % = 1.20
OL % = 1.00
OL % = 0.80
0
20
40
60
80
100
120
140