27.21.8.230.4000 Finder Step relay Clamp terminal

Why Choose the Finder 27.21.8.230.4000 Impulse Step Relay?

The Finder 27.21.8.230.4000 is a compact 10 A electromechanical impulse step relay designed for lighting control and fixed electrical installations. Part of the Finder Series 27 range, it provides convenient switching through momentary push-button operation.

Featuring a 230 V AC operating coil and one normally open (1 NO) contact, this relay allows a lighting circuit to be switched using successive control impulses. Its mechanically maintained operating principle means the selected contact position is retained after the control impulse ends.

The Finder 27.21.8.230.4000 combines a 10 A contact rating with a compact installation format suitable for recessed electrical mounting boxes and appropriate panel installations. It is a practical solution for residential and commercial lighting systems requiring control from multiple push-button locations.

Key Advantages

• 10 A impulse step relay for lighting and electrical switching.
• 230 V AC coil for compatible mains-voltage control circuits.
• One normally open contact for single-circuit switching.
• Mechanically maintained switching without continuous coil energisation.
• Supports lighting control from multiple momentary push-buttons.
• Compact design suitable for recessed electrical installations.
• Electromechanical operation provides straightforward switching control.
• Suitable for residential, commercial and building services applications.

Key Features

• Finder Series 27 electromechanical impulse relay.
• Type 27.21 single-contact switching arrangement.
• 230 V AC nominal coil voltage.
• 50/60 Hz AC control supply.
• 1 NO (SPST-NO) contact configuration.
• 10 A rated switching current.
• 250 V AC rated contact voltage.
• Two-position impulse switching operation.
• Mechanically maintained contact position.
• Silver tin oxide (AgSnO2) contact material.
• Compact mounting-box installation format.
• Suitable for momentary push-button control.

Efficient Single-Circuit Lighting Control with Impulse Switching

The Finder 27.21.8.230.4000 uses an electromechanical impulse mechanism that changes its normally open contact between the open and closed positions when a suitable control pulse is applied. After the impulse ends, the mechanical mechanism maintains the selected position without continuous coil power.

This arrangement makes the relay particularly useful for lighting circuits operated from several locations. Momentary push-buttons can provide control impulses to the relay, allowing convenient switching in corridors, staircases, shared spaces and other fixed electrical installations. The connected load must remain within the manufacturer's applicable switching ratings.

Typical Applications

• Residential lighting control.
• Staircase and corridor lighting systems.
• Commercial building lighting installations.
• Multi-location lighting control using momentary push-buttons.
• Office and shared-area lighting.
• Building automation switching circuits.
• Recessed electrical installation boxes.
• Single-circuit impulse-controlled electrical switching.