Pilz PST 4 - Type: DC; Function Description

PST 4
Operating Manual PST 4
18436-EN-06
8
Type: DC
} U
B
: 24 VDC; Order no. 720300
S23 S24S12S11
S33 S34Y2Y1
13 23 33 43
14 24 34 44
53 63
54 64
71
72
81
82
91
92
01
02
PST 4
S11 S12 S13 S24 S33 S34 Y1 Y2
A1 13 23 33 43 53 63 71 81 91 01
CH.1 IN
POWER
CH.2 IN
CH.1 OUT
CH.2 OUT
14 24 34 44 54 64 72 82 92 02 A2
*Insulation between the non-marked area and the relay contacts: Basic insulation (over-
voltage category III), Protective separation (overvoltage category II)
Function Description
The safety gate monitor PST 4 provides a safety-oriented interruption of a safety circuit.
When operating voltage is supplied the "POWER" LED will light. The unit is ready for oper-
ation when the feedback loop Y1-Y2 and the start circuit S33-S34 are closed.
} Input circuit closed within the simultaneity period (safety gate closed)
– The LEDs "CH.1 IN", "CH.2 IN" and "CH.1 OUT" and "CH.2 OUT" are lit
– Safety contacts 13-14, 23-24, 33-34, 43-44, 53-54 and 63-64 are closed, auxiliary
contacts 71-72, 81-82, 91-92 and 01-02 are opened. The unit is active.
} Input circuit is opened (safety gate opened)
– The LEDs "CH.1IN" and "CH.2 IN" go out.
– Safety contacts 13-14, 23-24, 33-34, 43-44, 53-54 and 63-64 are opened redund-
antly, auxiliary contacts 71-72, 81-82, 91-92 and 01-02 are closed.
– The LEDs "CH.1 OUT" and "CH.2 OUT" go out.
If the input circuits have already switched before supply voltage is applied, the PST 4 stops
the plant being enabled, to prevent an automatic start-up in accordance with
EN60204Pt7.5.
Reset function
The safety contacts and auxiliary contacts remain in rest condition (safety contacts are
open and auxiliary contacts are closed) if the supply voltage is applied when the safety gate
is closed. The safety and auxiliary contacts are not activated until the safety gate has been
opened and then closed again. N/C contacts in series with the safety gate limit switches S1
and S2 can simulate the opening of the safety gate.