Why Choose the Finder 77.B1.9.024.8650 Solid State Relay?
The Finder 77.B1.9.024.8650 is a 40 A single-phase solid state relay (SSR) designed for contactless switching of AC electrical loads in industrial automation, process heating and machinery control applications. Part of the Finder Series 77, this relay features a hockey puck-style housing for mounting onto a suitable control cabinet surface or heatsink.
Featuring a 3–32 V DC control input and a 24–660 V AC load switching range, the Finder 77.B1.9.024.8650 provides an interface between low-voltage DC control equipment and AC electrical loads. Its single normally open semiconductor output (1 NO / SPST-NO) supports a maximum load current of 40 A, subject to suitable heat dissipation and the manufacturer's operating limits.
The relay incorporates zero-cross switching, allowing conduction to begin near the AC voltage zero crossing to help reduce switching disturbances with suitable loads. Its silent, contactless operation, protected screw terminals and IP20 construction make it suitable for professionally designed industrial electrical control assemblies.
Key Advantages
- 40 A maximum load current for appropriately rated AC switching applications.
- 24–660 V AC load switching range for a wide range of single-phase industrial electrical systems.
- 3–32 V DC control input for compatible PLC outputs, electronic controllers and DC control circuits.
- Zero-cross switching helps reduce electrical disturbances when controlling suitable AC loads.
- Contactless semiconductor operation eliminates mechanical contact bounce.
- Silent switching without the operating noise of an electromechanical relay.
- High switching endurance without mechanical contact wear.
- Hockey puck-style housing for direct panel or heatsink mounting.
- Folding screw terminal cover for additional protection around electrical connections.
- Input and output terminals on opposite sides for organised control panel wiring.
- Compact construction for integration into industrial machinery and electrical control equipment.
- IP20 degree of protection for installation inside suitable electrical enclosures.
Key Features
- Finder Series 77 solid state relay.
- Type 77.B1 single-phase hockey puck-style relay.
- Maximum load current: 40 A.
- Nominal control voltage: 24 V DC.
- Control input voltage range: 3–32 V DC.
- Switched load voltage range: 24–660 V AC.
- Output configuration: 1 NO (SPST-NO).
- Number of switched phases: 1.
- Switching method: Zero-cross switching.
- Semiconductor output for contactless load switching.
- Panel or heatsink mounting using the hockey puck-style housing.
- Folding terminal protection cover.
- Screw terminal electrical connections.
- Input-to-output dielectric strength: 4,000 V AC.
- Housing dimensions: 45 mm × 59 mm × 29.4 mm.
- Operating ambient temperature: −30 °C to +80 °C.
- IP20 degree of protection.
Technical Specifications
- Manufacturer: Finder
- Series: 77
- Type: 77.B1
- Model: 77.B1.9.024.8650
- Product type: Single-phase solid state relay
- Housing style: Hockey puck
- Output configuration: 1 NO (SPST-NO)
- Maximum load current: 40 A
- Minimum switched load voltage: 24 V AC
- Maximum switched load voltage: 660 V AC
- Nominal control voltage: 24 V DC
- Minimum control voltage: 3 V DC
- Maximum control voltage: 32 V DC
- Switching method: Zero-cross switching
- Input-to-output dielectric strength: 4,000 V AC
- Mounting method: Panel or heatsink mounting
- Terminal connection: Screw terminals
- Terminal protection: Folding cover
- Housing width: 45 mm
- Housing length: 59 mm
- Housing depth: 29.4 mm
- Operating ambient temperature: −30 °C to +80 °C
- Degree of protection: IP20
- RoHS compliance: Yes
Reliable High-Voltage AC Switching for Industrial Heating and Automation
The Finder 77.B1.9.024.8650 provides semiconductor switching of AC electrical loads using a low-voltage DC control signal. Applying a suitable voltage within its 3–32 V DC input range activates the output, enabling compatible PLCs, temperature controllers and automation systems to control AC equipment without relying on mechanically operated relay contacts.
Its 24–660 V AC load switching range makes it suitable for a variety of industrial supply arrangements, provided the connected equipment remains within the specified voltage and current limits. The zero-cross switching characteristic is particularly useful for compatible resistive heating loads, where initiating conduction close to the AC voltage zero crossing can help reduce switching disturbances.
As a 40 A solid state relay, the Finder 77.B1.9.024.8650 requires appropriate thermal management. The maximum permissible load current depends on ambient temperature, heatsink performance, load characteristics and installation conditions. Suitable upstream protection, conductor sizing and manufacturer-specified derating must be considered. Solid state relays can also exhibit off-state leakage current, so a separate isolating device is necessary wherever safe electrical isolation is required.
Typical Applications
- Industrial electric heating systems.
- Resistance heater and heating element control.
- Industrial ovens and process heating equipment.
- Temperature-controlled machinery and production equipment.
- PLC-controlled AC load switching.
- Industrial automation control panels.
- Compatible lamp and lighting control applications.
- Solenoid and contactor driving circuits.
- Packaging and manufacturing machinery.
- Production line electrical switching systems.
- OEM machinery and electrical panel manufacturing.
- Applications requiring silent, contactless switching of AC loads.
