Additional Standard Features

• Sequential or Simultaneous Transfer Mode

• Bus Phase Undervoltage (27B)

• Frequency (81) and Rate of Change of Frequency (81R) for load

shedding

• Breaker Failure Source 1 and Source 2

• Bus VT Fuse‑Loss Detection (60FL)

• Auto Trip

• Auto Close

• Four dry output contacts (two trip and two close) for Source 1 and

Source 2. one lockout/ blocking output contact, and 3 programmable

output contacts (2 Form “a” and one Form “c”)

• Two Breaker Status 52b (or 52a) inputs for the Source 1 and Source

2 breakers, four programmable digital inputs

• All functions can be enabled or disabled

• Remote/Local control selection

• Device ON/OFF Control Selection

• M‑3931 Human‑Machine Interface (HMI) Module

• M‑3976 Status Module

• IRIG‑B time synchronization

• Oscillographic recording

• Two RS‑232 ports (front and rear) and one RS‑485 port* (rear)

*When using M‑3871 ISScom V10.02.XX to communicate with M‑4172

units with Firmware version V03.00.XX and higher, the RS‑485 port

(COM 3) is not available.

• S‑4200 or M‑3871 ISScom® Communications and Oscillographic

Analysis Software

Optional Features

• 5 A or 1 A models available

• 60 Hz or 50 Hz models available

• Available in vertical panel mount

• Redundant Power Supply

• External TCM and CCM available

• Ethernet port RJ‑45 10/100 Base‑T (MODBUS over TCP/IP)

• Ethernet port RJ‑45 10/100 Base‑T (IEC 61850 Protocol)