46
SIVACON S8 Planning Principles – Universal mounting design
4.3.6 Ratings for
motor feeders in SFD / HFD
Withdrawable units in SFD are applied up to a rated current
of 250 A. The two withdrawable unit variants SFD and HFD
can be mixed within one cubicle.
The following tables list the minimum withdrawable unit
sizes (Tab. 4/18 to Tab. 4/22) for motor feeders. Dependent
on the number of project-specific secondary devices and
the control wiring, larger withdrawable units might be
required.
More detailed information about motor feeders is available
from your local Siemens contact.
• Motor feeders for rated voltage
500 V and 690 V
• Motor feeders for tripping class up to CLASS 30
• Motor feeders for short-circuit breaking capacity
up to 100 kA
• Motor feeders with soft starter
• Motor feeders with frequency converter
• Small withdrawable units for star-delta circuit
The thermal interaction of the feeders in the cubicle has to
be and is considered by specifying the rated diversity factor
(RDF):
Permissible continuous operational current (motor feeder)
= rated current I
nc
x RDF
For the feeders in the cubicle, the rated diversity factor RDF
= 0.8 can be applied:
• regardless of the number of feeders in the cubicle
• regardless of the mounting position in the cubicle
For a rated diversity factor RDF > 0.8, the power grading
next in size is to be set for the motor feeder.
For cubicles with a very high packing and/or power density,
a project-specific assessment is recommended; information
about that is available from your Siemens contact.
The standard values for the operating currents of three-
phase asynchronous motors can be found in Chapter 10.
Small withdrawable unit
1)
Motor
power P
(AC-2/AC3)
Minimum withdrawable unit size
at 35 °C ambient temperature
Height 150 mm Height 200 mm
Direct
contactor
Reversing
circuit
Direct
contactor
Reversing
circuit
0.25 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
0.37 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
0.55 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
0.75 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
1.1 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
1.5 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
2.2 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
3 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
4 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
5.5 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
7.5 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
11 kW
¼, ½ ¼, ½ ¼, ½ ¼, ½
15 kW
½ ½ ¼, ½ ½
18.5 kW
½ ½ ¼, ½ ½
Tab. 4/18: Minimum withdrawable unit sizes for:
fused motor feeders, 400 V, CLASS 10,
with overload relay, type 2 at 50 kA
Normal withdrawable unit
Motor
power P
(AC-2/AC3)
Minimum withdrawable unit height
at 35 °C ambient temperature
Direct
contactor
Reversing
circuit
Star-delta
0.25 kW
100 mm 100 mm 150 mm
0.37 kW
100 mm 100 mm 150 mm
0.55 kW
100 mm 100 mm 150 mm
0.75 kW
100 mm 100 mm 150 mm
1.1 kW
100 mm 100 mm 150 mm
1.5 kW
100 mm 100 mm 150 mm
2.2 kW
100 mm 100 mm 150 mm
3 kW
100 mm 100 mm 150 mm
4 kW
100 mm 100 mm 150 mm
5.5 kW
100 mm 100 mm 150 mm
7.5 kW
100 mm 100 mm 150 mm
11 kW
100 mm 100 mm 150 mm
15 kW
150 mm 150 mm 150 mm
18.5 kW
150 mm 150 mm 200 mm
22 kW
150 mm 150 mm 200 mm
30 kW
200 mm 200 mm 200 mm
37 kW
200 mm 200 mm 200 mm
45 kW
200 mm 200 mm 250 mm
55 kW
400 mm 500 mm 250 mm
75 kW
400 mm 500 mm 250 mm
90 kW
400 mm 500 mm 500 mm
110 kW
500 mm 600 mm 500 mm
132 kW
500 mm 600 mm 500 mm
160 kW
500 mm 600 mm 500 mm
200 kW
600 mm 700 mm 700 mm
250 kW
600 mm 700 mm 700 mm
1)
Type: ¼ = small withdrawable unit size ¼
½ = small withdrawable unit size ½