40.61.7.110.1021 Finder Miniature PCB relay 1pole 16A DC 110V

Finder 40.61.7.110.1021 – 110 V DC 16 A Miniature PCB Relay, 1CO, AgNi, Wash-Tight

The Finder 40.61.7.110.1021 is a compact 110 V DC miniature power relay designed for industrial automation, electronic control equipment and printed circuit board assemblies. Part of the renowned Finder 40 Series, this relay combines a 16 A rated contact current, one changeover contact (1CO / SPDT) and a sensitive DC coil in a space-efficient electromagnetic switching component.

Featuring silver-nickel (AgNi) contacts, the Finder 40.61.7.110.1021 provides dependable switching for compatible resistive and industrial control loads. Its 110 V DC coil enables higher-voltage DC control systems to operate an electrically separate load circuit without requiring the control circuit to carry the load current directly.

This specific version incorporates 3.5 mm PCB terminal pins and RT III wash-tight environmental protection. These characteristics make it particularly suitable for professional PCB manufacturing, including compatible soldering and cleaning processes.

With its 500 mW sensitive DC coil, reinforced coil-to-contact insulation and compact relay housing, the Finder 40.61.7.110.1021 offers a practical solution for engineers seeking reliable electrical switching within industrial electronic assemblies.

Key Advantages

• 16 A rated contact current for compatible electrical loads.
• 110 V DC sensitive coil for higher-voltage DC control systems.
• One changeover contact (1CO / SPDT) provides flexible switching.
• Silver-nickel (AgNi) contact material for dependable electromechanical operation.
• 500 mW nominal coil consumption reduces control power requirements.
• RT III wash-tight construction supports compatible PCB cleaning processes.
• 3.5 mm terminal pin length for direct PCB mounting.
• Monostable, non-latching operation provides a defined de-energised contact position.
• Reinforced coil-to-contact insulation supports electrical separation.
• 6 kV impulse withstand capability between coil and contacts.
• 8 mm creepage and clearance between coil and contact circuits.
• Compact miniature housing for space-conscious equipment design.
• 5 mm contact terminal pitch for PCB integration.
• Wide −40 to +85 °C operating temperature range.
• Finder 40 Series construction for professional industrial and electronic applications.

Key Features

• Finder 40 Series miniature electromagnetic power relay.
• Type 40.61 single-pole construction.
• 110 V DC nominal coil voltage.
• Sensitive DC coil, 0.5 W.
• 23.5 kΩ nominal coil resistance.
• 4.7 mA nominal coil current.
• One changeover contact (1CO).
• SPDT / Form C contact arrangement.
• 16 A rated contact current.
• 30 A maximum peak contact current.
• 250 V AC rated contact voltage.
• 400 V AC maximum switching voltage.
• 4,000 VA AC-1 switching capacity.
• 1,000 VA AC-15 switching capacity at 230 V AC.
• Silver-nickel (AgNi) contacts.
• RT III wash-tight protection.
• 3.5 mm PCB terminal pins.
• 5 mm contact pin pitch.
• Approximately 10 ms operate time.
• Approximately 3 ms release time.
• 6 kV coil-to-contact impulse withstand.
• Reinforced insulation design.
• Direct through-hole PCB mounting.

How the Finder 40.61.7.110.1021 Relay Works

The Finder 40.61.7.110.1021 operates using an electromagnetic coil to move a mechanical changeover contact. Its 110 V DC control coil is electrically separate from the load contacts, allowing a compatible DC control circuit to operate another electrical circuit.

When the coil is de-energised, the common contact is connected to the normally closed (NC) terminal. Applying the appropriate 110 V DC control voltage energises the coil, moving the common contact away from the NC terminal and onto the normally open (NO) terminal.

When the coil voltage is removed, the electromagnetic field collapses and the spring mechanism returns the contact to its original position. This is known as monostable operation, meaning the relay does not retain its energised contact position without coil power.

The relay's 500 mW sensitive DC coil has a nominal resistance of 23.5 kΩ and draws approximately 4.7 mA at its rated voltage. The relatively low coil current is useful in compatible industrial control circuits where power consumption is an important consideration.

Because this is a 110 V DC relay, the coil must be driven from a control circuit designed for the appropriate voltage. It should not be connected directly to low-voltage microcontroller outputs or to an AC control supply.

When a semiconductor device controls the relay coil, suitable inductive transient suppression should be considered. A correctly selected flyback diode or alternative suppression arrangement can protect the driving electronics, although some suppression methods increase relay release time.

16 A Contact Switching Performance

The Finder 40.61.7.110.1021 features a 16 A changeover contact with silver-nickel (AgNi) contact material. This provides versatile switching capability for compatible resistive loads, control circuits and auxiliary equipment.

Finder specifies a 4,000 VA AC-1 rating for the 40.61 relay family, corresponding to the nominal resistive switching capability at its rated AC voltage. For industrial control applications, the published AC-15 switching capacity is 1,000 VA at 230 V AC.

The permissible switching current depends on the electrical load. Motors, solenoids, transformers, electronic power supplies and LED drivers can produce inrush currents or switching transients that require additional assessment.

The relay's 30 A maximum peak current rating must not be confused with its continuous rated contact current of 16 A. Likewise, its 400 V AC maximum switching voltage does not mean that the full 16 A load can be switched at that voltage.

When switching DC loads, the permitted breaking current decreases as the DC voltage increases. Finder's published DC-1 ratings for the 40.61 family include 16 A at 24 V DC, 0.6 A at 110 V DC and 0.25 A at 220 V DC.

For reliable service life, the selected relay should be evaluated against the connected load's steady-state current, inrush current, switching frequency and required number of operating cycles.

RT III Wash-Tight PCB Construction

The Finder 40.61.7.110.1021 is supplied in an RT III wash-tight configuration. This environmental protection classification is intended to support compatible PCB assembly cleaning processes.

The relay uses 3.5 mm terminal pins for direct through-hole PCB mounting. Unlike the longer-pin plug-in variants of the Finder 40.61 family, this version is intended for soldered PCB installation rather than insertion into a standard relay socket.

The compact housing measures approximately 29 × 12.4 × 25 mm, making it suitable for industrial electronic assemblies where PCB space must be managed carefully.

During PCB design, engineers should follow the manufacturer's recommended pin layout and provide adequate copper track width, electrical clearance, creepage distance and thermal management for the intended switching current.

Finder recommends suitable spacing between relays installed on the same PCB to support thermal performance. Soldering, washing and drying processes must follow the manufacturer's assembly guidance to maintain the relay's environmental protection.

The RT III designation describes the relay's sealed construction for manufacturing processes; it is not an enclosure IP rating or permission to expose the completed electrical assembly to unrestricted moisture or outdoor conditions.

Reinforced Insulation and Electrical Safety

The Finder 40.61 relay family incorporates reinforced insulation between the coil and contact circuits, with an 8 mm creepage and clearance design and a 6 kV impulse withstand rating.

This insulation system is valuable where a DC control circuit must operate a separate electrical load, provided the complete equipment is designed to the relevant safety requirements.

The relay also has a published 4,000 V AC dielectric strength between coil and contacts and 1,000 V AC dielectric strength between open contacts.

These component ratings do not replace the need for appropriate system-level insulation, overcurrent protection, PCB conductor separation and electrical enclosure design.

Typical Applications

• Industrial automation control boards.
• 110 V DC control and signalling systems.
• PCB-mounted electrical switching assemblies.
• Industrial machine control electronics.
• Electrical signal changeover circuits.
• Building automation equipment.
• Industrial monitoring and alarm systems.
• Control of appropriately rated auxiliary loads.
• Power management and control electronics.
• Remote electrical switching systems.
• Electronic instrumentation.
• Industrial equipment manufacturing.
• Professional PCB assembly production.
• Wash-process-compatible electronic assemblies.
• Maintenance and replacement of compatible Finder 40.61 relays.