Pilz PST 4 - Operating Modes; Timing Diagram; Installation

PST 4
Operating Manual PST 4
18436-EN-06
9
Operating modes
} Dual-channel operation with detection of shorts across contacts: Redundant input cir-
cuit, PST 4 detects
– earth faults in the start and input circuit,
– short circuits in the input circuit,
– shorts across contacts in the input circuit.
} Automatic start: Unit is active once the input circuit has been closed.
} Manual start: Unit is active once the input circuit and the start circuit are closed.
} Increase in the number of available contacts by connecting contact expander modules
or external contactors/relays.
Timing diagram
[1] [2]
Legend
} Power: Supply voltage
} Start: Start circuit
} Input: Input circuits
} Output safe: Safety contacts
} [1]: Automatic start
} [2]: Manual start
} a: Input circuit closes before start circuit
} b: Start circuit closes before input circuit
} t
1
: Switch-on delay
} t
2
: Delay-on de-energisation
} t
3
: Recovery time
Installation
} The unit should be installed in a control cabinet with a protection type of at least IP54.
} Use the notch on the rear of the unit to attach it to a DIN rail (35 mm).
} When installed vertically: Secure the unit by using a fixing element (e.g. retaining
bracket or end angle).