Current Measurement With Two Current Transformers On The Line Side - Siemens SINAMICS DCM Operating Instructions Manual

6.6.2

Current measurement with two current transformers on the line side

(on delivery)
Configuration as shown in Chapter "Connecting the external power unit (Page 76)".
Current transformer
XB-1
XB-2
XB-3
XB-4
The current transformers must have no external connection to ground. Only terminals XB-2
and XB-3 may be used for this purpose.
Table 6- 5 Recommended current transformers
Armature Ratio
current
Up to 600 A 6000 : 1
Up to 850 A 8500 : 1
Up to 1200 A 12000 : 1
Up to 1600 A 16000 : 1
Up to 2400 A 24000 : 1
Up to 3000 A 30000 : 1
S700 switch positions:
The position of the S700 means that the difference amplifier on the power interface for the
Control Module (see "Measuring circuit" figure) is not active. The load voltages from X3 are
connected directly to the control electronics.
Load resistors
R =
B
U =
B
ü =
I =
d
SINAMICS DCM Control Module
Operating Instructions, 12/2018, A5E34888669A
k1 Current transformer T1 signal
l1 Ground reference
l2 Ground reference
k2 Current transformer T2 signal
Part number
C771
C850
C772
C868
C773
C740
Load resistor
Load voltage (= mean value over 1 current crest, not the rms value or mean value over the
entire period); recommended value = 1 V
Transformation ratio of the current transformer (I2/I1) (in general, ü = 1/number of turns)
Rated armature DC current
6.6 Measurement of the armature current
Ordering data
MLFB
6RY1702-0AA03
6RY1702-0AA06
6RY1702-0AA04
6RY1702-0AA07
6RY1702-0AA05
6RY1702-0AA10
2 – 3 connected
5 – 6 connected
8 – 9 connected
K line side
L device side
Primary side
Hole 31 × 5.5 mm
Hole ∅ 22 mm
Hole 61 × 10.5 mm
Hole ∅ 11 mm
Cu cylinder piece
Height 45 mm, hole ∅ 12.2 mm
Hole ∅ 12.2 mm
Connecting
99