SR3D Safety Switching Device – Reliable Safety Technology for Continuous Operation in Combustion Systems

The SR3D is a universally applicable safety switching device with three safe relay outputs. It is specially designed for continuous operation in combustion systems and complies with the requirements of EN 50156-1. Certified by Germanischer Lloyd (GL) under approval number 32915-06HH, the SR3D is also approved for maritime applications, such as waste incineration plants on ships.

The SR3D combines multiple safety functions into one compact device. It monitors emergency stops, sliding protective doors, and light curtains, and it can be used as a secure coupling relay. The safety level corresponds to PL e, Category 4, and SILCL 3, meeting the highest safety standards. With a width of only 22.5 mm, the SR3D is space-saving and easy to integrate into control cabinets.

The SR3D supports both automatic and manually monitored start-up modes. It operates with a variable power supply (AC/DC 24 V, AC 115 V, or AC 230 V) and provides a maximum switching capacity of 8 A at 250 VAC (ohmic load). It features three instantaneous safety contacts and one signaling output.

The SR3D is available with fixed screw terminals, pluggable screw terminals, or push-in spring terminals in TWIN design, enabling quick and secure installation. Matching accessories such as pluggable terminal sets and spacers ensure safe and easy handling.

Technical Data:

Feature:

• Safety function: Emergency stop monitoring, sliding protective door monitoring, light curtain monitoring, secure coupling relay
• Certified according to: EN 60204-1, DIN EN ISO 13849-1, EN 62061, EN 50156-1, EN 746-2, IEC 61508 Parts 1-2 and 4-7, IEC 61511-1
• Approvals: CE, TÜV, GL
• Supply voltage: AC/DC 24 V / AC 115 V / AC 230 V
• Number of safety contacts: 3
• Max. switching capacity of safety contacts: 8 A / 250 VAC (ohmic load)
• Number of signaling outputs: 1
• Number of instantaneous safety contacts: 3
• Number of delayed safety contacts: -
• Start behavior: Automatic start or manually monitored start
• PL, Cat., SILCL (EN ISO 13849-1, EN/IEC 62061): PL e, Cat. 4, SILCL 3
• Width: 22.5 mm

Ordering Information:

• Item No. Fixed screw terminals: 472272 (24 V) / 472271 (115 V) / 472270 (230 V)
• Item No. with pluggable screw terminals: 474272 (24 V) / 474271 (115 V) / 474270 (230 V)
• Item No. with push-in spring connection in TWIN design: 475272 (24 V) / 475271 (115 V) / 475270 (230 V)

Accessories:

• Item No. EKLS4; Set of pluggable screw terminals: 472592
• Item No. EKLT4; Set of push-in spring connections in TWIN design: 472595
• Item No. Spacer for defined minimum distance between two safety relays (see derating): 472596