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DISTRIBUTORS

B1

B1

.146

VALVES ISO 5599/1 SERIES SAFE AIR

®

EXAMPLE OF A SAFETY CIRCUIT WITH A SINGLE VALVE

Below is an example of a wiring diagram for controlling Metal Work SAFE AIR

®

single valves using Pilz

®

components.

Circuit components:

- a Pilz

®

safety module PNOZ

®

s3 for controlling the emergency stop button; terminal Y32 indicates the status of the module, which can be relayed

to the machine control logic

- an emergency stop button S1 (Pilz

®

- PIT

®

es Set) linked to terminals S11-S12-S22-S23 of the PNOZ

®

s3

- a Metal Work SAFE AIR

®

solenoid valve, the 24 VDC coil of which is fed by terminal 14 of the PNOZ

®

s3 (the other terminal of the coil is 0 V);

the valve’s Hall-effect sensor is 24 VDC

- a start/reset button S2

- a relay K1, controlled by the valve sensor; an NO contact of the relay is in series with button S2 of the PNOZ

®

s3.

Expected behaviour with the system operating correctly:

- system deactivated:

• contact 14 is OFF

• the coil is de-energized

• the sensor is ON

• relay K1 is energized

• contact K1 is closed

• contact Y32 is OFF

- with the system activated via the start/reset button:

• contact 14 is ON

• the coil is energized

• the sensor is OFF

• relay K1 is de-energized

• contact K1 is open

• contact Y32 is ON

In the event of a malfunction (e.g. spool jam), the coil is de-energized but the sensor remains OFF, relay K1 remains de-energized, contact K1 remains

open (preventing subsequent restarts) and contact Y32 is OFF.

In the event of a valve fault, the circuit in the diagram below does not allow relief of the compressed air system. Sensor status must be monitored to

assess valve operation. Contact Y32 indicates the status of the PNOZ

®

s3, not the status of the sensor.

All the electrical connections between the various components must comply with the applicable safety regulations.

If the emergency button is operated at a frequency of 1 actuation per hour, the circuit activates a safety function with PL = c (calculations made with

the PAScal programme by Pilz

®

). Responsibility for final checking that PL lies with the person assembling the circuit.