The wenglor SG4-00VA000R2 is a safety interface relay specifically engineered to serve as the critical bridge between wenglor's SG-I safety light curtains (or SB-I safety light arrays) and the machine's safety-related load circuit. It is not a general-purpose safety relay, but rather a dedicated basic module designed to process the OSSD signals from these specific electro-sensitive protective equipment (ESPE) and provide a safe, galvanically isolated switching interface. The unit provides two failsafe, floating (potential-free) relay outputs, ensuring that safety-relevant circuits can be interrupted with high reliability.

An important technical nuance of the SG4-00VA000R2 is that it is not assigned its own independent safety category or performance level. Instead, when used for its intended purpose with SG-I or SB-I ESPE, the relay is capable of fulfilling the requirements of the highest safety integrity levels: Performance Level e (PL e) and Category 4 according to EN ISO 13849-1, Safety Integrity Level 3 (SIL 3) according to EN 62061, and Type 4 according to EN 61496-1. The safety level of the overall system is therefore determined by the connected light curtain or light array. The product is CE compliant and developed in accordance with EU directives 2006/42/EC and 2014/30/EU, with a maximum service life of 20 years.

From an electrical perspective, the SG4-00VA000R2 features several important operational characteristics. Its power supply is uniquely derived from the OSSD outputs of the connected ESPE, eliminating the need for a separate power source. The relay outputs are rated for 3A at 250V AC. Response times are 20ms for automatic start and 8ms for manual reset; critically, the use of the relay unit adds an additional 8ms to the overall system response time, which must be accounted for when calculating safety distances. To extend the service life of the relay contacts, the use of a spark arrestor is strongly recommended. The device features a terminal block for wiring and an LED switching status indicator for visual diagnostics. Installation must be performed inside a control cabinet that meets at least IP54 protection requirements.

The SG4-00VA000R2 is designed for straightforward DIN rail mounting, with a compact 22.5mm width that saves valuable panel space. It operates reliably within an ambient temperature range of -20°C to 50°C. The device includes essential safety functions such as cross-circuit detection (which must be enabled) and external device monitoring (EDM), which is required to be active. The basic module can handle a variety of input signals—including emergency stop buttons, safety switches, and safety light curtains—making it suitable for a wide range of applications. Typical applications include potential-free disconnection of machinery, monitoring of emergency stop buttons and safety switches, monitoring of safety light curtains and multi-beam light arrays, and safety shutdown for stop categories 0 and 1.

Technical Specifications