Engineering
 
24 M-Max Series Adjustable Frequency Drive
 
    MN04020003E—October 2013    www.eaton.com
 
Motor and Circuit Type
 
The motor’s stator winding can be connected in a star or 
delta configuration, in accordance with the rated operational 
data on the nameplate.
 
Example of a Motor Ratings Plate
Star and Delta Circuit Types
 
The three-phase motor with the rating plate based on the 
figure shown above, can be run in a star or delta connection. 
The operational characteristic curve is determined by the 
ratio of motor voltage and motor frequency, in this case.
 
87-Hz Characteristic Curve
 
In the delta circuit with 400V and 87 Hz, the motor shown in 
the figure above was released with three times-fold output 
(~1.3 kW).
Because of the higher thermal loading, using only the next 
higher motor output according to the list (1.1 kW) is 
recommended. The motor (in this example) therefore still has 
1.47-fold higher output compared with the listed output 
(0.75 kW).
With the 87-Hz characteristic curve, the motor also works in 
the range from 50 to 87 Hz with an unattenuated field. The 
pull-out torque remains at the same level as in input 
operation with 50 Hz.
The heat class of the motor must be at least F in 87-Hz 
operation.
 
V/Hz-Characteristic Curve
 
The following table shows the allocation of possible 
frequency inverters depending on the input voltage and the 
type of circuit.
 
Assignment of Frequency Inverters to Example Motor Circuit (See Figure Above)
 
Notes
 
 
Star connection: 400V, 50 Hz.
 
 
Delta connection: 230V, 50 Hz.
 
 
Delta connection: 400V, 87 Hz.
 
 
Note the permitted limit values of the motor.
/400       V230
3.5/2
0.75S1
0.79
cos
kW
RPM
1430 50 Hz
A
U1 V1 W1
W2 U2 V2
U1 V1 W1
W2 U2 V2
0
8750
400
U
2
 (V)
f (Hz)
f
max
230
 
Frequency Inverters MMX12AA3D7_ MMX32AA3D7_ MMX34AA2D4_ MMX34AA4D3_
 
Rated operational current 3.7A 3.7A 2.4A 4.3A
Input voltage 1 AC 230V 1 AC 230V 3 AC 400V 3 AC 400V
Motor circuit Delta Delta Star Delta
V/Hz-characteristic curve
 
 
Motor current 3.5A 3.5A 2.0A 3.5A
Motor voltage 3 AC 0–230V 3 AC 0–230V 3 AC 0–400V 3 AC 0–230V
Motor speed 1430 min
 
–1
 
1430 min
 
–1
 
1430 min
 
–1
 
2474 min
 
–1 
 
 
Motor frequency 50 Hz 50 Hz 50 Hz 87 Hz