Pilz 774140 PZE 9 Safety Relay Expansion Module

The Pilz 774140 (PZE 9) is a contact expansion module designed for safety-related applications in industrial automation. As a dedicated add-on device without delay-on de-energization, this module increases the number of available safety contacts in safety circuits. The PZE 9 is driven by a base safety unit such as an emergency stop relay, safety gate monitor, or light curtain evaluation device, expanding its switching capacity to additional loads. This makes the module suitable for applications where multiple contactors or output devices need to be controlled by a single safety monitoring circuit.

Output Contact Configuration

The PZE 9 provides 8 normally open (N/O) safety contacts and 1 normally closed (N/C) auxiliary contact. The eight safety contacts are positive-guided relay contacts that ensure reliable switching even under fault conditions. Each safety contact features voltage AC1 rating of 240 V with maximum current rating of 8 A. Contact voltage AC15 rating is 230 V with current rating of 5 A, suitable for controlling AC contactor coils and other inductive loads. DC13 rating at 24 V is 8 A. The auxiliary contact is typically used for status indication or monitoring purposes, providing feedback to the control system regarding the expansion module operating state. Positive-guided operation ensures that if a contact welds, the contacts cannot return to the normal position, preventing undetected failure modes in safety circuits.

Input Circuit and Operation Modes

The PZE 9 supports both 1-channel and 2-channel input wiring configurations. When used in 2-channel wiring with short-circuit detection, the module monitors for cross faults between input channels, providing enhanced fault detection capability. Without short-circuit detection, the module accepts simpler wiring for applications where cross-fault detection is not required. The expansion module is driven by a base unit that provides the safety evaluation logic; when the base unit energizes its internal relays, the PZE 9 outputs follow the same state, creating simultaneous switching of additional contacts. This parallel expansion approach preserves the safety integrity level achieved by the base unit. The module operates without delay-on de-energization, meaning its outputs de-energize immediately when the input signal from the base unit is removed.

Power Supply and Electrical Ratings

The PZE 9 is designed for operation on 24 V AC supply voltage, with power consumption of 7 VA. The supply voltage type is AC only, making this model suitable for applications where only AC control voltage is available. For use with DC systems, other models in the PZE series with 24V DC supply are available. The contacts use AgSnO2 contact material with a gold flash layer (+ 0.2 µm Au) for reliable switching at low voltages and currents. The contact material composition ensures good resistance to contact erosion under inductive load switching conditions. Relay contacts meet the requirements of EN 60947-4-1 and EN 60947-5-1 standards.

Environmental and Mechanical Specifications

The PZE 9 is housed in a 90 mm width DIN rail mount enclosure, with height of 87 mm and depth of 121 mm. Net weight is 600 g. The housing materials consist of ABS UL94 V-0 rated plastic for both the lower section and upper part, providing flame-retardant properties. The front plate material is also ABS UL94 V-0. Operating ambient temperature range spans from -10°C to +55°C, suitable for most industrial control cabinet environments. Humidity rating is 93% RH at 40°C, with condensation not permitted. The module meets climatic suitability requirements per EN 60068-2-78 and vibration requirements per EN 60068-2-6. The screw terminal type provides fixed terminals accepting conductors from 24 AWG to 10 AWG range, with screw torque specification per terminal type.

Standards and Compliance

The PZE 9 safety relay meets requirements of applicable international standards including EN 60947-5-1, EN 60204-1, VDE 0113-1, and EN 61000-6-2 for EMC. Overvoltage category rating is III or II depending on installation, with pollution degree 2. Clearance and creepage distances comply with EN 60947-1. Protection type for mounting is determined by the control cabinet installation, while terminal protection type is provided by standard terminal construction. Approvals include CCC (China Compulsory Certification), CE (Europe), UKCA (United Kingdom), cULus Listed (North America), EAC (Eurasian Economic Union), and TÜV certification. The product is intended for use in industrial environments and is not permitted for use in residential or domestic areas where interference with radio and television reception could occur.

Application and Integration

The PZE 9 is suitable for expanding safety circuits in applications including emergency stop installations, safety gate monitoring, light curtain evaluation, two-hand control systems, and safety mats. The addition of 8 safety contacts allows connection of multiple contactors, solenoid locks, or other output devices to a single safety evaluation device. The contact expansion module connects directly to the base safety unit terminals, typically through a dedicated expansion interface or by wiring between the base unit safety outputs and the PZE 9 inputs. The module then provides isolated relay contacts capable of switching loads independently, allowing distribution of safety outputs to multiple machine zones or functions.