Why Choose the Finder 77.A1.8.230.8250 Solid State Relay?
The Finder 77.A1.8.230.8250 is a 25 A single-phase solid state relay (SSR) from the Finder 77 Series, designed for reliable, contactless switching of AC electrical loads. Featuring a compact hockey-puck-style housing, it provides an effective switching solution for industrial heating equipment, lighting circuits, automation systems and electrical control panels.
With a 230 V AC nominal control input, an operating input range of 90–280 V AC and an output switching range of 24–280 V AC, this relay allows an AC control signal to operate a separate AC load circuit. Its 25 A rated output current and single normally open semiconductor output make it suitable for appropriately rated industrial applications.
The Finder 77.A1.8.230.8250 incorporates zero-crossing switching, which initiates conduction near the AC voltage zero crossing to help reduce switching interference. Its silent operation, screw terminals, protective terminal cover and panel or heat-sink mounting arrangement make it particularly suitable for installations requiring frequent switching without mechanical contact wear.
Key Advantages
- 25 A rated output current for appropriately rated single-phase AC loads.
- 230 V AC nominal control input for industrial AC control systems.
- 90–280 V AC input operating range for flexible control integration.
- 24–280 V AC load switching range for compatible electrical equipment.
- Zero-crossing turn-on helps minimise switching interference.
- Contactless semiconductor switching eliminates mechanical contact bounce.
- Silent operation for equipment requiring frequent switching.
- Single normally open output for straightforward load control.
- Hockey-puck-style housing for direct panel or heat-sink mounting.
- Relay-style terminal arrangement with input and output connections on opposite sides.
- Screw terminals and protective cover for practical installation.
- IP20 protection rating for use within suitable electrical enclosures.
Key Features
- Finder 77 Series industrial solid state relay.
- Model: 77.A1.8.230.8250.
- Single-phase AC output.
- Output configuration: 1 NO / SPST-NO equivalent.
- Rated output current: 25 A.
- Rated output voltage: 230 V AC.
- Load switching voltage: 24–280 V AC.
- Nominal control voltage: 230 V AC.
- Control input operating range: 90–280 V AC.
- Control input frequency: 50/60 Hz.
- Switching function: Zero-crossing turn-on.
- Contactless electronic switching.
- Relay-style terminals positioned on opposite sides.
- Hockey-puck housing with protective screw cover.
- Panel or heat-sink mounting.
- Screw terminal connections.
- Ambient operating temperature: −30 to +80 °C.
- Protection rating: IP20.
Technical Specifications
- Manufacturer: Finder
- Series: 77 Series
- Manufacturer part number: 77.A1.8.230.8250
- Product type: Solid state relay
- Housing style: Hockey puck
- Number of phases: 1
- Output contact equivalent: 1 normally open (SPST-NO)
- Rated output current: 25 A
- Rated output voltage: 230 V AC
- Load voltage range: 24–280 V AC
- Nominal control voltage: 230 V AC
- Control voltage range: 90–280 V AC
- Control supply type: AC, 50/60 Hz
- Switching mode: Zero-crossing
- Terminal arrangement: Relay style, input and output on opposite sides
- Connection type: Screw terminals
- Mounting method: Panel or heat-sink mounting
- Housing width: 45 mm
- Housing height: 59 mm
- Housing depth: 29.4 mm
- Ambient operating temperature: −30 to +80 °C
- Protection classification: IP20
- Product category: Solid State Relays
Reliable Zero-Crossing Switching for Industrial AC Loads
The Finder 77.A1.8.230.8250 uses an electronic semiconductor output instead of mechanical relay contacts. When an appropriate AC control voltage is applied to its input terminals, the relay activates its output at a suitable AC voltage zero crossing, allowing current to flow through the connected load. When the control input is removed, the output stops conducting according to the semiconductor switching characteristic.
This zero-crossing switching method is particularly useful for suitable resistive loads, including industrial heating equipment, where reduced switching interference and frequent operation are desirable. The relay should be mounted on an appropriately selected heat sink or thermally suitable panel arrangement, with load current, ambient temperature, protective devices and heat dissipation considered during installation. As a semiconductor switching device, it does not replace a mechanical isolator.
Typical Applications
- Industrial electrical heating and temperature control.
- Heating elements and resistive load switching.
- Industrial lighting control systems.
- Solenoid and contactor control circuits.
- Industrial automation and electronic load control.
- Machinery requiring frequent, silent AC switching.
- Process control and manufacturing equipment.
- Packaging and production machinery.
- OEM electrical control assemblies.
- Panel-mounted semiconductor switching installations.
