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

Connecting
6.6 Measurement of the armature current
If two current transformers are already present in a V-circuit, these can be connected directly
to terminals XB-1 to XB-4 in order to reduce the wait time for current reversal (greater
dynamic response to torque changes).
Interposing current transformers may only be connected directly downstream of a current
transformer and not downstream of a V-circuit!
6.6.2

Current measurement with two current transformers on the line side

(on delivery)
Configuration as described in the section titled "Connecting the external power unit"
Current transformers
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- 4 Recommended current transformers
Armature current Ratio
Up to 600 A 6,000:1
Up to 850 A 8,500:1
Up to 1,200 A 12,000:1
Up to 1,600 A 16,000:1
Up to 2,400 A 24,000:1
Up to 3,000 A 30,000:1
S700 switch positions:
The position of the S700 means that the difference amplifier at power interface C98043-
A7109 (see "Measuring circuit" figure) is not active. The load voltages from X3 are
connected directly to the control electronics.
94
k1 Current transformer T1 signal
l1 Ground reference
l2 Ground reference
k2 Current transformer T2 signal
Order number
C98130-A1023-C771
C98130-A1023-C850
C98130-A1023-C772
C98130-A7023-C062
C98130-A1023-C773
C98130-A1023-C740
2 – 3 connected
5 – 6 connected
8 – 9 connected
K line side
L modular 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
SINAMICS DCM Control Module
Operating Instructions, 06.2010, C98130-A7067-A1-02-7619