Siemens MICROMASTER 420 用户手册

MICROMASTER 420    Operating Instructions 

 

6SE6400-5AA00-0BP0 

67

 

I

1

1

2

U

12

3

U

1N

I

1N

Z

N

Z

Z

I

I

I

3

2

1

=

=

U

 

3

U

U

U

1Ν

31

23

12

⋅

=

=

=

Z

2

I

U

1

12

⋅

=

3

Z

Z

Y

12,

∆

12,

=

U

3

U

Y

12,

1

∆

12,

=

I

1

1

2

U

12

3

I

12

Z

Z

Z

I

3

1

I

I

I

1

31

23

12

⋅

=

=

=

U

U

U

31

23

12

=

=

I

3

1

I

Y

1,

∆

1,

=

Z

3

2

I

U

1

12

⋅

=

 

Fig. 3-19 

Star / delta circuit configurations 

When a motor with a delta circuit configuration (e. g. V

N

∆

, motor

 = 230 V) is fed from a 

frequency inverter, where the rated voltage corresponds to the star circuit 
configuration (e.g. 400 V frequency inverter), then it is important to proceed as 
follows and observe the following: 

 

The motor must have the appropriate voltage strength. 

 

Above the rated motor frequency, the iron losses in the motor increase over-
proportionally. This is the reason that above this frequency, the thermal motor 
torque should be reduced. 

 

For the quick commissioning, the rating plate data for the delta circuit 
configuration should be entered or the rating plate must be appropriately 
converted. 

 

The drive inverter must be designed for the higher current (delta circuit 
configuration). 

 

The 87 Hz characteristic is independent of the control type. 

 

When using the 87 Hz characteristic, the mechanical motor limits must be 
taken into account (refer to Catalog M11). 

For the 87 Hz characteristic, the ratio between the voltage and frequency (V/f 
characteristic) remain constant. This is the reason that the following relationships 
apply: 

P = power

P

U

U

P

N∆

N∆

N1

N1

⋅

=

f

U

U

f

N∆

N∆

N1

N1

⋅

=

(

)

n

f

f

n

∆

N∆

N1

N1

p

min

s

 

60

 

 

+

−













=

f

f

N1

f

N

∆

U

U

N

∆

U

N1

f = frequency
n = speed
p = pole pair No.

(400 V)

(230 V)

(50 Hz)

(87 Hz)

 

Fig. 3-20 

V/f characteristic