LS 4

Features

• True RMS voltage (A and B side)
• True RMS current (A side)
• Synch-check functionality
• Dead bus start functionality
• Synchronous networks functionality
• Remote control of frequency, voltage, and real power
• Zero power transfer control (softload)
• Configurable trip/control set points
• Config. delays for each alarm
• 7 configurable relay outputs
• Two-line LC display
• Synchronization over transformer possible

Protections

• Overvoltage            (ANSI 59)
• Undervoltage         (ANSI 27)
• Overfrequency       (ANSI 81O)
• Underfrequency     (ANSI 81U)
• Phase/vector shift  (ANSI 78)
• df/dt ROCOF           (81RL)

Functions

• Calculation of setpoint values which are transmitted to the genset controls (e.g. GCP) for synchronization and load control
• Circuit breaker close command issued when LS 4 is enabled and the two sources are synchronized.
• Open command to the CB with a discrete input command or with the detection of one of the available protection functions.