Finder 7S.34.8.120.4310 – 7S Series Relay modules with forcibly guided contacts

Why Choose the Finder 7S.34.8.120.4310 Safety Relay?

The Finder 7S.34.8.120.4310 is a professional 120 V AC safety relay module with forcibly guided contacts, designed for industrial machinery, automation systems and safety-related electrical control circuits. Part of the Finder 7S Series, this modular electromechanical relay features four contacts arranged as 3 normally open (NO) and 1 normally closed (NC), providing multiple switching paths and a dedicated feedback contact.

Its Class A forcibly guided contact construction, designed in accordance with EN 61810-3, enables appropriately engineered external monitoring circuits to detect specified contact failures, including welded contacts. This makes the Finder 7S.34.8.120.4310 particularly useful in control systems where reliable switching and contact-state feedback are essential.

Featuring a 120 V AC nominal coil, 6 A rated contact current, 250 V AC nominal switching voltage and silver tin oxide contacts, this relay is suitable for a wide range of industrial control applications. Its compact 22.5 mm-wide housing, screw terminals, integrated coil status indicator and standard DIN rail mounting simplify installation in industrial electrical cabinets.

Key Advantages

• 120 V AC coil for compatible industrial AC control systems.
• 3 NO + 1 NC contact configuration provides three normally open switching contacts and one normally closed feedback contact.
• Class A forcibly guided contacts support fault detection in monitored safety-related circuits.
• 6 A rated contact current for suitable industrial switching loads.
• 250 V AC rated switching voltage for compatible electrical applications.
• Silver tin oxide (AgSnO) contacts provide durable electromechanical switching performance.
• Integrated LED coil status indication assists commissioning and troubleshooting.
• Screw terminal connections support secure and familiar control panel wiring.
• 22.5 mm module width helps conserve valuable DIN rail space.
• 35 mm DIN rail mounting provides convenient installation in electrical enclosures.
• IP20 protection rating for use within suitable protective cabinets.
• Wide ambient operating temperature range supports demanding industrial environments.
• Suitable for incorporation into properly engineered SIL 2 and PL d safety-related systems, subject to complete system assessment.

Key Features

• Finder 7S Series modular relay with forcibly guided contacts.
• Four-pole contact arrangement: 3 NO + 1 NC.
• Class A mechanically linked contacts according to EN 61810-3.
• 120 V AC nominal coil voltage.
• 50/60 Hz AC supply compatibility.
• 93 V AC minimum operate voltage.
• 12 V AC maximum release threshold specification.
• 6 A rated contact current.
• 250 V AC nominal switching voltage.
• 1,500 VA AC-1 switching capacity.
• Silver tin oxide contact material.
• Approximately 1.1 W coil power.
• 12 ms typical operate time.
• 10 ms typical release time.
• Integrated LED coil status indicator.
• Monostable, non-latching operation.
• Screw terminal connections.
• 35 mm DIN rail mounting.
• 22.5 mm-wide housing.
• −40 to +70 °C operating temperature range.
• IP20 enclosure protection rating.

How Forcibly Guided Contacts Improve Safety Circuit Monitoring

The Finder 7S.34.8.120.4310 uses forcibly guided contact technology to support the monitoring of electromechanical switching functions. Unlike conventional relay arrangements, its normally open and normally closed contacts are mechanically linked to maintain a defined relationship between their operating positions.

If a normally open contact becomes welded closed, the mechanical guidance prevents the normally closed contact from returning to its closed position. A suitably designed external monitoring circuit can detect this abnormal condition and initiate an appropriate response before further machine operation.

The relay's 3 NO + 1 NC configuration is especially useful where three normally open switching contacts are required alongside a normally closed feedback contact. The normally open contacts may be used to switch suitable control loads, while the normally closed contact can provide feedback to a safety controller or monitoring circuit.

This arrangement makes the relay suitable for applications involving monitored output stages, machine guarding, emergency-stop control interfaces and industrial safety-related switching. However, the Finder 7S.34.8.120.4310 is not a complete standalone safety controller. The safety performance of an installation depends on the complete circuit architecture, diagnostic coverage, component reliability and validation.

120 V AC Coil Operation for Industrial Control Systems

The Finder 7S.34.8.120.4310 features a 120 V AC nominal coil, making it suitable for industrial equipment operating with compatible AC control supplies. This distinguishes it from DC-powered versions of the Finder 7S Series and makes it useful where an AC control voltage is already available.

The relay has a specified minimum operate voltage of 93 V AC and is designed for 50/60 Hz operation. Correct coil voltage selection is essential, as applying an incompatible supply can prevent correct operation or damage the relay.

The 22.5 mm-wide housing is designed for installation on a standard 35 mm DIN rail. Its screw terminals provide conventional wiring connections, while the integrated LED offers a convenient indication of coil energisation during commissioning and troubleshooting.

With an IP20 protection rating, the relay should be installed inside a suitable protective electrical cabinet. Its specified ambient operating temperature range of −40 to +70 °C supports a broad range of industrial applications when installed in accordance with the manufacturer's instructions.

Typical Applications

• Industrial machinery safety-related control circuits.
• Safety PLC switching and feedback interfaces.
• Emergency-stop control systems with suitable external monitoring.
• Machine guarding and interlocking circuits.
• Industrial automation control panels.
• Manufacturing and production line equipment.
• Conveyor and material-handling systems.
• Packaging and processing machinery.
• Industrial lifting and handling equipment.
• Automated warehouse control systems.
• Monitored relay output circuits.
• Control systems requiring three normally open switching contacts.
• Applications requiring a normally closed contact for feedback monitoring.