Finder 77.B1.8.230.8650 – 77 Series Modular solid state relays

Why Choose the Finder 77.B1.8.230.8650 Solid State Relay?

The Finder 77.B1.8.230.8650 is a high-performance 40 A AC-output solid state relay (SSR) designed for reliable, silent and contactless switching in industrial automation, electrical heating systems, lighting control and machinery applications. Part of the Finder Series 77 solid state relay range, this model combines zero-crossing semiconductor switching with a robust hockey puck-style enclosure.

Featuring a 24–660 V AC output switching range, the Finder 77.B1.8.230.8650 provides a rated load current of 40 A, subject to appropriate heat sinking and operating conditions. Its 230 V AC nominal control input accepts an operating voltage range of 90–280 V AC, making it suitable for integration into compatible industrial mains-voltage control circuits.

The relay incorporates one normally open electronic output (1 NO / SPST-NO) and uses zero-crossing switching to activate compatible AC loads near the voltage waveform's zero crossing. With a compact 45 × 59 × 29.4 mm housing, screw terminals and folding protective terminal covers, it provides a practical solution for professional industrial electrical installations.

Key Advantages

• 40 A rated output current for appropriately designed industrial AC switching applications.
• 24–660 V AC switching range for a wide variety of compatible AC loads.
• 230 V AC nominal control input for industrial control circuits.
• 90–280 V AC control voltage range for flexible installation.
• Zero-crossing switching helps minimise electrical disturbances in suitable applications.
• Contactless semiconductor operation eliminates mechanical contact wear and bounce.
• Silent switching without mechanical relay clicking.
• 500 A peak surge current capability for 10 ms under specified conditions.
• 1600 V repetitive peak OFF-state blocking voltage for high-voltage AC switching applications.
• 4 kV input-to-output dielectric withstand for electrical separation.
• Hockey puck-style housing for mounting on a suitable panel surface or heat sink.
• LED status indication for convenient monitoring of the control input.
• IP20 protection rating for installation within suitable electrical enclosures.

Key Features

• Finder Series 77 industrial solid state relay.
• Type 77.B1 hockey puck configuration.
• Single-phase AC-output switching.
• One normally open electronic output (SPST-NO).
• 40 A rated load current.
• 24–660 V AC switching voltage range.
• 230 V AC nominal control voltage.
• 90–280 V AC control input operating range.
• Zero-crossing turn-on characteristic.
• Semiconductor-based contactless switching.
• Silent and spark-free switching operation.
• 500 A peak surge current for 10 ms.
• 1600 V repetitive peak OFF-state voltage.
• Low OFF-state leakage current.
• High switching endurance without mechanical contact wear.
• LED input status indication.
• 4 kV input-to-output dielectric withstand.
• Screw-type electrical terminals.
• Folding protective screw covers.
• Control and load terminals arranged on opposite sides.
• Panel or heat sink mounting.
• IP20 degree of protection.

High-Voltage Zero-Crossing Switching for Industrial AC Loads

The Finder 77.B1.8.230.8650 uses semiconductor switching technology to control AC electrical loads without conventional mechanical contacts. When the specified control voltage is applied, the relay electronically activates its output, providing quiet operation and eliminating mechanical contact bounce.

Its zero-crossing turn-on characteristic initiates conduction near the point where the AC voltage waveform crosses zero. This can help reduce switching transients and electromagnetic interference in compatible resistive loads, particularly industrial electric heating applications.

The relay's 24–660 V AC switching range distinguishes it from lower-voltage Series 77 variants. This extended voltage capability makes the device suitable for a broader range of AC electrical installations, provided the connected load, supply characteristics and protective arrangements remain within the manufacturer's specifications.

With a 40 A rated output current and 500 A peak surge current capability for 10 ms, the relay supports industrial switching applications requiring substantial load capacity. The actual permissible continuous current depends on heat sinking, ambient temperature and installation conditions.

The hockey puck-style enclosure is designed for mounting on suitable control cabinet sheet metal or a dedicated heat sink. This mounting arrangement allows heat generated by the semiconductor switching element to be transferred away from the relay.

Thermal management is essential. At rated current, the relay can dissipate approximately 48 W. A suitably selected heat sink, correct mounting technique and adequate ventilation are necessary to maintain the required operating temperature.

The relay provides 4 kV AC dielectric withstand between input and output, helping maintain electrical separation between the control circuit and switched load. Its LED indication supports convenient checking of the input state during commissioning and maintenance.

As with other solid state relays, a small leakage current may flow through the output when switched off. The Finder 77.B1.8.230.8650 must therefore not be treated as a mechanical isolator. Appropriate overcurrent protection and a separate means of electrical isolation should be provided where required.

Typical Applications

• Industrial electric heating systems.
• Resistive heating element switching.
• Industrial ovens, furnaces and temperature-controlled equipment.
• High-voltage AC load switching within the specified operating range.
• Commercial and industrial lighting control.
• AC solenoid and contactor driver circuits.
• Industrial machinery and manufacturing equipment.
• Programmable logic controller (PLC) controlled switching.
• Industrial process automation.
• Building automation and electrical control systems.
• Electrical control cabinets and machinery panels.
• Applications requiring silent and frequent switching.
• OEM industrial control and automation assemblies.