Four-wire switch circuit

Electric point machine

The four-wire turnout circuit is a standardized in Germany connection of turnout drives to control elements of interlockings . Electromechanical interlockings, relay interlockings and electronic interlockings come into consideration as interlockings.

Four cable cores are required. The distance to the point is limited depending on the electrical resistance of the line and the point machine used. Usual values are 6 km to 8 km.

Both the drive energy for the electric motor (for example 230 V 50 Hz AC voltage as three-phase current ) during the switchover and the position of the switch position in the idle state are transmitted via the four cable cores for monitoring.

Examples of point machines that work with the four-wire switch circuit:

Siemens S700
Siemens S700K ( IP 54 )
Thales L700H
Thales FieldTrac 6343 L826H

Individual evidence

↑ Four-wire switch circuit , basic circuit
↑ Walter Jonas. Operating electronic interlockings - The regular operation , page 33. Eisenbahn-Fachverlag 2001. ISBN 3-9808002-0-2
↑ greatly simplified four-wire switch circuit (Figure 2.5.6)
↑ Example connection device (.pdf, German)

[1] Four-wire switch circuit , basic circuit

[2] Walter Jonas. Operating electronic interlockings - The regular operation , page 33. Eisenbahn-Fachverlag 2001. ISBN 3-9808002-0-2

[3] greatly simplified four-wire switch circuit (Figure 2.5.6)

[4] Example connection device (.pdf, German)