Pilz PSWZ X1P static monitoring

Misconception 3: Auxiliary contacts 41-42 can be used for safety interlocking. Error, it is only used for indication and does not guarantee safety performance.

Maintenance and lifespan

Relay mechanical lifespan: 10000000 cycles. But the electrical lifespan depends on the load current and voltage. Reference service life chart (page 33):

Under AC-1 (resistive load, 240V/6A), approximately 100000 cycles.

Under AC-15 (inductive load, 230V/3A), approximately 1000000 cycles.

Over 1000000 times under DC-1 (24V/6A).

Under DC-13 (24V/4A, inductive), approximately 300000 cycles.

Extend contact life: For inductive loads, arc extinguishing measures must be taken (such as RC absorption circuits, varistors, diodes, etc.). The DC coil needs to be connected in parallel with a freewheeling diode.

Regular inspection: Check the terminal screws for looseness (torque 0.5Nm) every six months and remove dust from the control cabinet.

Scrap disposal: Dispose of according to local electronic waste regulations, with no user replaceable fuses or batteries inside.

Interpretation of Safety Feature Data

To assist engineers in conducting safe calculations, PSWZ X1P provides the following values:

Standard parameter values

EN ISO 13849-1 Performance Level (PL) PL e

EN ISO 13849-1 Category Cat. 4

EN ISO 13849-1 PFH₀ [1/h] 6.23 × 10⁻⁹

EN ISO 13849-1 Task Time TM [year] 20

EN IEC 62061 SIL CL SIL 3

EN IEC 62061 PFH₀ [1/h] 6.23 × 10⁻⁹

The PFH value has taken into account the B10d value of the relay contacts and is effective under the load conditions given in the service life diagram. If the actual switching frequency is high, PFH will increase accordingly and needs to be recalculated.

The system security level depends on the architecture of the entire security loop, rather than individual components. It is recommended to use Pilz's PAScal software for circuit calculation.

Common application Q&A

Q1: Can PSWZ X1P be used for DC travel motors?

A: Sure, but only single-phase mode can be used (L1 connected to positive, L3 connected to negative, L2 suspended). At this point, there is only one measurement channel, and the security level will decrease (unable to reach Cat.4). For high demand applications, it is recommended to use three-phase motors.

Q2: If the motor has a mechanical brake, is static detection still necessary?

A: I need it. The brake can only keep the shaft from rotating, but there may still be residual magnetic voltage inside the motor. PSWZ X1P can detect this voltage to prevent misjudgment. Please make a static judgment after the brake is closed.

Q3: Can feedback loops use normally closed contacts of multiple contactors in series?

A: Okay. This can improve safety, as any contactor adhesion will cut off the feedback loop and prevent the safety output from closing. All contacts must be of the positive guided type for mechanical interlocking.

Q4: Can PSWZ X1P directly replace the old model PNOZ X1P?

A: Yes, it is. PSWZ X1P is a successor model of PNOZ X1P, with compatible functions, but the definition of connection terminals may be slightly adjusted. Please check the wiring diagram.