Pilz PNOZ s5 Time-Delay Safety Relay with Adjustable Delay

Overview

The Pilz PNOZ s5 is a PNOZsigma safety relay with two instantaneous safety contacts and two safety contacts that open with an adjustable delay after the safety function is triggered. This delay-on de-energisation function is needed whenever a hazardous movement has a run-down time: drives and spindles that coast, presses that must complete a stroke, or vessels that must be depressurized before a guard is released. The delay can be set from 0.04 s up to 300 s with two rotary switches on the front.

Seven Star LLC supplies the Pilz PNOZ s5 to machine builders, panel builders and plant owners in Oman and the GCC, with engineering support in Muscat. The Pilz PNOZ s5 datasheet values are given in the operating manual attached to this page, which lists several product IDs, including 24 V DC and 48 to 240 V AC/DC types, so our team will confirm the correct variant against the control voltage and terminal type of your cabinet before an order is placed.

Operating Principle

When an E-STOP is pressed, a safety gate is opened or a light grid is interrupted, the Pilz PNOZ s5 opens its two instantaneous safety contacts within a typical 15 ms and a maximum of 20 ms. The two delayed safety contacts stay closed for the programmed delay time and then open, so a brake supply or a drive holding function remains available until the hazard has decayed. The delay time is the product of two switch settings: the time switch t[s] and the factor n, so a setting of 4 s and a factor of 5 gives a delay of 20 s, and the shortest delay that can be set is 0.04 s.

The manual states for the Pilz PNOZ s5 a time accuracy of ±1 % plus ±20 ms and a repetition accuracy of the same size, and it quotes a larger repetition tolerance under error conditions, so the delay must be chosen with the maximum stopping time of the machine in mind. Like the other PNOZsigma relays, the PNOZ s5 uses a redundant, self-monitoring circuit, and it tests the correct opening and closing of its relays automatically in each on-off cycle. The mode selector offers automatic start, manual start, monitored start on the rising or falling edge and a start-up test, in single-channel or dual-channel wiring with or without short detection.

Engineering Design of the Pilz PNOZ s5

The Pilz PNOZ s5 is housed in a 22.5 mm wide polycarbonate enclosure that is 120 mm deep and 98 or 100 mm high depending on the terminal type, with a weight of 235 g. The three rotary switches of the Pilz PNOZ s5 for mode, time and factor sit under the front cover, and the manual recommends sealing them with an adhesive seal to protect against manipulation. It also warns that the switches must never be adjusted during operation, because an error message then appears and the safety contacts open until the supply voltage is switched off and on.

Plug-in screw or spring-loaded terminals simplify wiring and replacement of the Pilz PNOZ s5, and a side connector can take one PNOZsigma contact expansion module. A semiconductor output reports the state to a PLC, and six LEDs show supply, inputs, outputs, start circuit and faults. The delayed contacts carry their own safety characteristic data in the manual: PL e Category 4 and SIL 3 with a PFH of 2.34E-09 per hour. The contacts are rated AC1 240 V 6 A and DC1 24 V 6 A, with AC15 3 A at 230 V and DC13 4 A at 24 V for the switching duties listed in EN 60947-5-1.

Key Features

The Pilz PNOZ s5 adds an adjustable stopping delay to the PNOZsigma concept. Its main capabilities include:

• Two instantaneous and two delay-on de-energisation safety contacts in one 22.5 mm housing.
• Adjustable delay time from 0.04 s up to 300 s using the t[s] and n rotary switches.
• Time accuracy of ±1 % + ±20 ms, with stated repetition accuracy.
• Safety rating up to PL e (Category 4) and SIL 3 for both instantaneous and delayed contacts.
• Rotary mode switch for automatic, manual and monitored start, with or without start-up test.
• Single-channel and dual-channel operation, with or without detection of shorts across contacts.
• Semiconductor output, six status LEDs and plug-in screw or spring-loaded terminals.
• Side connector for one PNOZsigma contact expansion module and an adhesive seal option for the rotary switches.

Industrial Applications

The Pilz PNOZ s5 is used where stopping takes time: large motors and fans with run-down, hydraulic presses, lifting equipment with brakes, and centrifuges, mixers and extruders in process plants. In Oman and the GCC it fits motor control centres, pump and compressor packages and manufacturing lines in Sohar, Duqm and Salalah where a controlled stop with delayed removal of power (stop category 1) is the chosen safety strategy. With the Pilz PNOZ s5 the two instantaneous contacts can remove the enabling signal at once, while the delayed contacts keep brakes or holding circuits energized for the set time.

Larger plants that mix relay-based safety and safety PLCs may also review the ABB AC500-S safety PLC, the HIMA HIQuad safety PLC system or the Yokogawa ProSafe-RS safety instrumented system in our catalog. The Pilz manual reminds users that the PL and SIL of a complete safety function must be assessed separately and that a risk assessment is mandatory before use of the Pilz PNOZ s5. Seven Star LLC can help choose the correct delay-time range, supply voltage and terminal type, and can support spare-part planning.

Technical Specifications

Key parameters of the Pilz PNOZ s5 taken from the manufacturer operating manual (21397-EN-18):

Request a Quote for Pilz PNOZ s5

To request a quotation for the Pilz PNOZ s5, check availability and lead time or download the manufacturer operating manual from the document tab on this page, send the product ID, supply voltage, terminal type and required delay time to the Seven Star LLC instrumentation team. We supply the Pilz PNOZ s5 to customers in Oman and the GCC.

Other Pilz models from Seven Star LLC: Pilz PNOZ s3 safety relay, Pilz PNOZ s4 safety relay and Pilz PNOZ m B0 base unit.