Finder 77.B3.8.230.8671 – 77 Series Modular solid state relays

Why Choose the Finder 77.B3.8.230.8671 Three-Phase Solid State Relay?

The Finder 77.B3.8.230.8671 is a high-performance 40 A three-phase solid state relay (SSR) from the Finder 77 Series, designed for reliable, contactless switching of industrial AC loads. Featuring a three-pole normally open semiconductor output arrangement, it provides a practical alternative to conventional electromechanical switching devices in suitable heating, motor control and industrial automation applications.

With a 90–280 V AC control input and a 24–660 V AC load switching range, the Finder 77.B3.8.230.8671 supports a wide range of three-phase electrical control systems. Its 40 A rated output current enables the switching of appropriately rated loads, subject to suitable heat-sink selection, operating temperature and load characteristics.

The relay incorporates random turn-on switching, allowing rapid semiconductor activation without deliberately waiting for the next AC voltage zero crossing. Its compact hockey-puck-style housing, screw terminals and panel or heat-sink mounting arrangement make it suitable for demanding industrial installations requiring frequent, silent and mechanically wear-free switching.

Key Advantages

• 40 A rated output current for suitably rated three-phase AC loads.
• Three normally open semiconductor outputs for three-phase switching.
• 90–280 V AC control input for industrial AC control systems.
• 24–660 V AC load switching range for compatible three-phase equipment.
• Random turn-on switching for rapid response to control signals.
• Contactless semiconductor operation eliminates mechanical contact bounce.
• Silent switching without conventional mechanical contact arcing.
• Hockey-puck-style construction for panel or heat-sink installation.
• Contactor-style terminal arrangement for practical electrical wiring.
• Screw terminals for secure control and load connections.
• −30 to +80 °C ambient operating temperature range, subject to operating limits.
• IP20 protection rating for installation within suitable electrical enclosures.

Key Features

• Finder 77 Series industrial solid state relay.
• Model: 77.B3.8.230.8671.
• Three-phase AC load switching.
• Output configuration: 3PST-NO / 3 normally open equivalents.
• Rated output current: 40 A.
• Rated output voltage: 600 V AC.
• Load switching voltage range: 24–660 V AC.
• Nominal control voltage: 230 V AC.
• Control input voltage range: 90–280 V AC.
• Switching mode: Random turn-on.
• Operating frequency range: 47–400 Hz.
• Semiconductor switching without mechanical output contacts.
• Panel or heat-sink mounting.
• Contactor-style input and output terminal arrangement.
• Screw terminal connections.
• Housing dimensions: 105 × 78 × 36.5 mm.
• Ambient operating temperature: −30 to +80 °C.
• Protection classification: IP20.
• CE, UKCA, EAC and cURus approvals or markings.

High-Speed Three-Phase Semiconductor Switching for Industrial Control

The Finder 77.B3.8.230.8671 operates using semiconductor switching elements rather than conventional mechanical contacts. When an appropriate 90–280 V AC control signal is applied, its three semiconductor outputs are activated to switch the connected three-phase AC load. The random turn-on characteristic allows switching to begin in response to the control signal without intentionally delaying activation until the next voltage zero crossing.

This operating principle supports frequent and silent switching in suitable industrial heating and motor control applications. The relay's 40 A output rating depends on appropriate thermal management, and a correctly selected heat sink is required to achieve the specified operating performance. Suitable overcurrent protection, wiring, ventilation and safe electrical isolation must be provided separately. Because the device uses semiconductor outputs, it may pass a small leakage current even when switched off.

Typical Applications

• Three-phase industrial heating systems.
• Industrial motor control with suitably rated loads.
• Manufacturing machinery and automated production equipment.
• Three-phase resistive load switching.
• Industrial temperature and process control systems.
• Electrical control cabinets and automation panels.
• Packaging and material handling equipment.
• Industrial ovens and heating assemblies.
• OEM machinery requiring frequent, silent switching.
• Industrial applications requiring random turn-on semiconductor outputs.