Pilz PSWZ X1P Safety Static Monitoring Relay

Product Overview and Usage

PSWZ X1P is a safety static monitoring relay developed by Pilz, which is used to monitor whether the motor is completely stationary after the equipment is stopped, and only allows the safety door to open or the dangerous action to be released in a stationary state.

Applicable: EN 60204-1 Safety circuits, equipment with dangerous moving parts

Measurement method: Detect the regenerative residual voltage after the motor is powered off. If the voltage is below the threshold, it is judged to be stationary

Safety specifications (core)

Safety standard level

EN ISO 13849-1 PL e，Category 4

EN IEC 62061 / 61508 SIL 3

PFHd (hazard failure frequency) 6.23 × 10 ⁻⁹/h

Mission Time (TM) 20 years

Hardware structure and terminals

Measurement input

L1/L2/L3: Connected to motor winding, supports up to 690V

Dual channel: CH1 (L1-L3), CH2 (L2-L3)

power input

A1 / A2：24~240V AC/DC， Wide voltage compatibility

control input

Reset input: High level>15V effective, low level<5V

Feedback loop Y1-Y2: Monitoring external contactor

relay output

Safe output: 13-14, 23-24 (2-channel normally open, redundant)

Auxiliary output: 41-42 (1 normally closed, not suitable for safety circuits)

Semiconductor output

Y32: Status output (static=high)

Y35: Fault output (fault=high)

Working principle

Power on process

Perform a 1.5s self-test after powering on to test the output, measurement circuit, and feedback circuit

Self check passed and the circuit is normal, entering standby mode

Static judgment logic

Dual channel voltage lower than Uon at the same time → judged as stationary

The safety contact is closed, and the OUTPUT light is on

Start/motion judgment

Any channel voltage higher than Uoff=2 × Uon → judged operation

Redundant disconnection of safety contacts, output prohibited

Fault status

Exceeding simultaneity time (maximum 7s) → FAULT light on

Reset pulse is required to clear the fault

Electrical parameters (key)

Parameter values

Measurement voltage range: 0~690V

Response threshold Uon 7.5mV~3V (adjustable for multiple models)

Release threshold Uoff 2 × Uon

Power supply range 24~240V AC/DC

Simultaneous monitoring time up to 7 seconds

Safe contact capacity AC1: 6A/240V; AC15: 3A/230V

Insulation withstand voltage 6kV, 690V level

Working temperature -10 ℃~+55 ℃

Protection level: body IP40, terminal IP20

Installation and wiring requirements

Install

35mm DIN rail installation, can be installed in any direction

Installation cabinet protection ≥ IP54

Wiring specifications

The measurement line uses shielded cables, and the shielding layer is grounded at one end

Separate wiring of control lines and power lines

The safety output front-end must be equipped with a fuse (maximum 6A fast melting)

threshold setting

Potentiometer adjustment, if the CH.1 IN/CH.2 IN light is on when the motor is stationary, it is considered qualified

Status and fault indication

Meaning of LED

POWER power supply is normal

CH.1 IN/CH.2 IN channel 1/2 reaches the static threshold

OUTPUT safety contact closed

Fault (asynchronous, open circuit, self-test failure)

Maintenance and testing

Weekly testing: Start the motor → Stop → Confirm that it is stationary before closing the output

Replacement must comply with electronic waste regulations

Prohibition of modification, disassembly, and unauthorized maintenance

Key issues

Question 1: What is the function of the “dual channel redundant monitoring” of PSWZ X1P? How to use a single-phase motor?

Answer: Dual channel monitoring is used to improve safety and reliability, and any channel failure can still be safely detected; When using a single-phase motor, the equipment will automatically allocate a single measurement signal to two channels, achieving equivalent redundant monitoring while still maintaining the PL e/Cat.4 safety level.

Question 2: What is the relationship between the static threshold Uon and the release value Uoff? Why is it designed like this?

Answer: Release value Uoff=2 × Uon, using hysteresis design. The purpose is to prevent frequent suction/disconnection of output contacts when the voltage fluctuates near the threshold, avoid contact vibration and system instability, and ensure clean and reliable safety status determination.

Question 3: What are the common reasons and reset methods for PSWZ X1P experiencing FAULT light on and safety contacts unable to close?

Answer: Common reasons: ① The dual channel voltage is not synchronized for more than 7 seconds; ② The measurement circuit is open/disconnected; ③ Feedback loop disconnected; ④ Self check failed. Reset method: Apply a high-level → low-level pulse signal to the reset input terminal to clear the fault.