Finder 77.H1.9.024.8250 – 77 Series Modular solid state relays

Why Choose the Finder 77.H1.9.024.8250 Solid State Relay?

The Finder 77.H1.9.024.8250 is a high-performance 125 A single-phase solid state relay (SSR) designed for reliable, silent and rapid switching of AC electrical loads in industrial automation and control systems. As part of the Finder 77 Series solid state relay range, it combines semiconductor switching technology with a compact hockey puck-style housing, providing an effective alternative to conventional electromechanical relays in demanding switching applications.

This solid state relay features zero-crossing switching technology, which activates the output close to the AC voltage zero-crossing point to help reduce electrical interference and switching transients. Unlike mechanical relays, the Finder 77.H1.9.024.8250 operates without moving contacts, eliminating contact bounce and mechanical switching noise while supporting frequent switching operations and long service life.

With a 125 A rated load current, a 24–280 V AC output switching range and a 3–32 V DC control input, this relay is particularly suitable for industrial heating systems, resistive loads, lighting equipment and automated process control. Its panel-mounted construction allows installation directly onto suitable control cabinet surfaces or a correctly sized heatsink for effective thermal management.

Key Advantages

• High-capacity 125 A solid state relay for industrial AC load switching.
• 3–32 V DC control input compatible with suitable PLC outputs and electronic control systems.
• 24–280 V AC switching voltage range for single-phase electrical loads.
• Zero-crossing switching helps minimise electrical interference during switching.
• Silent, contactless operation eliminates mechanical contact bounce and switching noise.
• High switching endurance makes the relay suitable for frequently operated industrial equipment.
• Compact hockey puck-style housing with protective folding screw covers.
• Panel or heatsink mounting supports effective installation and thermal management.

Key Features

• Finder 77 Series industrial solid state relay.
• 125 A rated output current.
• Single-phase, normally open (1 NO / SPST-NO) output.
• 3–32 V DC control voltage range.
• 24–280 V AC load switching voltage.
• Zero-crossing turn-on technology for AC load control.
• 2250 A maximum peak surge current for a 10 ms pulse.
• 47–400 Hz operating frequency range.
• Contactless semiconductor switching for silent operation.
• Low control power requirements for electronic automation interfaces.
• Relay-style terminal arrangement with input and output connections on opposite sides.
• Screw terminals with protective folding covers.
• Suitable for mounting on control cabinet sheet metal or an appropriately rated heatsink.
• Designed for heater control, lighting loads, solenoids and contactor driver applications.

Reliable Solid State Switching for Industrial Automation

Solid state relays such as the Finder 77.H1.9.024.8250 use electronic semiconductor components rather than mechanical contacts to switch electrical loads. When a suitable DC control signal is applied, the relay activates its AC output circuit using zero-crossing technology. This allows connected equipment to be controlled without the contact bounce, arcing and mechanical wear associated with conventional electromechanical switching devices.

The Finder 77 Series is particularly suited to industrial applications involving frequent switching cycles, including electric heating systems, process temperature regulation and automated production equipment. Its 125 A output capability supports high-current switching applications, provided that appropriate heatsinking, load derating, electrical protection and installation practices are followed. The relay is intended for AC loads and must not be used as a substitute for a safety isolation device.

Typical Applications

• Industrial electric heating and temperature control systems.
• Heating elements, ovens and process heaters.
• PLC-controlled AC load switching.
• Industrial machinery and automated production equipment.
• Resistive load switching in electrical control panels.
• Lighting and lamp control systems.
• Solenoid and contactor coil control within suitable load ratings.
• Packaging, manufacturing and process automation equipment.