User Manual Manual

Applications/Wiring 9-4
Publication 825-UM001B-EN-P January 2001
Short-Circuit Protection of Medium/High-Voltage Motors
Main Circuit (with Cat. No. 825-MST Option Card)
3-Phase Current Evaluation
Figure 9.5 Basic Unit for Short-Circuit Protection
1
35
246
U1
825-MCM
825-M
F1
U2
M
3 ~
K1
A1
A2
QA
L1 L2 L3
QM
Variants
• 2-phase current evaluation
• 2-phase current evaluation and earth (ground) fault
protection with core balance transformer
U1 Converter module
Cat. No. 825-MCM2
Cat. No. 825-MCM20
U2 Main current transformer
…A/5 A or …A/1 A
For choice refer to Chapter 2