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 specifically designed for continuous operation in combustion systems and complies with the stringent requirements of EN 50156-1. Certified by Germanischer Lloyd (GL) under approval number 32915-06HH, the SR3D is also approved for use in maritime environments, such as waste incineration plants on ships.

The SR3D combines several safety functions into one compact device. It monitors emergency stop, sliding protective doors, and light curtains and also serves as a secure coupling relay. With a safety classification of PL e, Category 4, and SILCL 3, it meets the highest safety standards. Its compact design, with a width of only 22.5 mm, allows for space-saving integration into control cabinets.

The SR3D supports both automatic and manually monitored start modes. It offers flexible power supply options with AC/DC 24 V, AC 115 V, or AC 230 V. With a maximum switching capacity of 8 A at 250 VAC (ohmic load), the SR3D guarantees reliable switching operations. It features three instantaneous safety contacts and one signaling output, which can be used to monitor the switching status.

The SR3D can be mounted using fixed screw terminals, pluggable screw terminals, or push-in spring terminals in TWIN design, enabling quick and secure installation. A wide range of accessories is also available, including pluggable terminal sets and spacers to maintain the minimum distance between two safety relays.

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