Why Choose the Finder RB.14.9.250.0000 Bistable Relay?
The Finder RB.14.9.250.0000 is an industrial 8 A bistable relay designed for control, signalling and switching applications requiring reliable operation and retention of the last switching state. Part of the Finder RB Series, this modular relay features four changeover contacts (4CO / 4PDT), a 220–250 V DC control supply and convenient 35 mm DIN rail mounting.
Unlike a conventional monostable relay, which generally requires continuous coil energisation to maintain its operated position, the Finder RB.14.9.250.0000 uses a bistable operating mechanism. Separate SET and RESET control signals change the relay between its two stable states, allowing it to retain its last commanded position without continuous coil power.
This makes the relay particularly useful for industrial automation, power generation facilities, electrical distribution panels, automatic warehouses and control systems where a defined switching state must be maintained between control commands.
With its four independent changeover contact sets, the Finder RB.14.9.250.0000 can switch or signal multiple circuits simultaneously. Its modular construction incorporates SET and RESET controls, LED command indication and screw-terminal connections for straightforward installation and maintenance.
Key Advantages
- Bistable operation: Maintains the last selected switching state without continuous coil energisation.
- Separate SET and RESET commands: Provides defined control of the relay's two stable positions.
- Four changeover contacts: Offers four independently accessible SPDT contact sets within one relay.
- 8 A contact rating: Suitable for appropriately rated industrial control and auxiliary switching loads.
- 220–250 V DC supply: Designed for compatible higher-voltage DC control systems.
- 35 mm DIN rail mounting: Integrates into standard industrial electrical cabinets.
- LED command indication: Helps technicians identify the presence of control commands.
- SET and RESET controls: Supports local operation and commissioning.
- Low holding power requirement: The relay does not require continuous coil energisation to retain its switching state.
- Screw-terminal connections: Provide practical wiring access during installation and servicing.
- Cadmium-free contacts: Uses contact materials designed without cadmium.
- IP20 enclosure protection: Suitable for installation inside appropriately protected electrical cabinets.
- Wide operating temperature range: Supports demanding industrial environments.
- Modular relay construction: Combines multiple switching functions in a single DIN rail component.
Key Features
- Finder RB Series industrial bistable relay.
- Manufacturer part number: RB.14.9.250.0000.
- Relay type: Bistable / latching relay.
- Contact configuration: 4CO / 4PDT.
- Rated contact current: 8 A.
- Control supply: 220–250 V DC.
- Nominal contact voltage: 250 V AC.
- Maximum contact voltage: 400 V AC.
- Separate SET and RESET inputs.
- Two stable operating positions.
- LED command status indication.
- Local SET and RESET controls.
- 35 mm DIN rail mounting to EN 60715.
- Screw-terminal connections.
- IP20 protection rating.
- Cadmium-free contact construction.
- Suitable for industrial control and signalling systems.
Technical Specifications
- Manufacturer: Finder
- Product series: RB Series
- Manufacturer part number: RB.14.9.250.0000
- Product type: Industrial bistable relay
- Relay operation: Electromechanical latching / bistable
- Number of stable states: 2
- Number of changeover contacts: 4
- Contact arrangement: 4CO / 4PDT
- Rated contact current: 8 A
- Peak contact current: 15 A
- Nominal contact voltage: 250 V AC
- Maximum contact voltage: 400 V AC
- Rated AC1 load: 2,000 VA
- Rated AC15 load at 230 V AC: 350 VA
- Single-phase motor rating at 230 V AC: 370 W
- DC control supply: 220–250 V DC
- Control arrangement: Separate SET and RESET commands
- Coil construction: Two-winding bistable arrangement
- Nominal DC coil power: 7 W
- SET operating time: Approximately 10 ms
- RESET operating time: Approximately 5 ms
- Mechanical endurance: 2 million operations
- Electrical endurance at rated AC1 load: 100,000 operations
- Contact material: Silver alloy, cadmium-free
- Mounting method: DIN rail
- DIN rail size: 35 mm
- DIN rail standard: EN 60715
- Terminal type: Screw terminals
- Protection rating: IP20
- Operating temperature: -40 to +55 °C
- Command indication: LED
- Local controls: SET and RESET
- EAN / GTIN: 8012823396651
How the Bistable Relay Mechanism Works
The defining feature of the Finder RB.14.9.250.0000 is its bistable switching mechanism.
A conventional monostable relay normally changes state when its coil is energised and returns to its original position when the coil supply is removed. A bistable relay behaves differently: it has two stable mechanical positions and can retain its last commanded state without continuous coil power.
The Finder RB.14.9.250.0000 uses separate control functions:
- SET: Commands the relay into its operated position.
- RESET: Commands the relay back to its alternative stable position.
Once a valid command has operated the mechanism, the contacts remain in the selected position until the opposite command is applied.
This is useful where equipment must maintain a switching condition between control signals or where continuous coil energisation would otherwise be unnecessary.
The bistable mechanism should not be confused with electronic memory or a programmable controller. The relay retains a physical contact position, but it does not provide logic processing, event recording or independent monitoring of the connected load.
The Finder RB.14.9.250.0000 incorporates four changeover contact sets, also described as 4CO or 4PDT.
Each changeover contact provides a common terminal and two alternative switching paths. When the relay changes state, the common terminal transfers between its normally closed and normally open connections.
Having four changeover contacts within one relay allows multiple electrical functions to be controlled from the same SET and RESET command arrangement.
For example, a single relay may be used to operate an auxiliary control circuit while simultaneously providing status signals to other equipment, provided the contacts are appropriately rated and the circuit design permits the arrangement.
The 8 A rated contact current applies under the manufacturer's specified conditions. The permissible switching current depends on the load type, voltage, switching frequency and required electrical life.
Inductive loads, motors and DC switching applications can impose different demands from resistive AC loads. Engineers should therefore check the appropriate utilisation ratings rather than assuming that every load can be switched at the full 8 A value.
220–250 V DC Control Supply
The Finder RB.14.9.250.0000 is designed for a 220–250 V DC control supply.
This distinguishes it from lower-voltage RB Series variants intended for 24 V, 48 V or 110–125 V DC applications.
Higher-voltage DC control systems are used in selected industrial installations, including power generation, electrical distribution and other equipment where dedicated DC auxiliary supplies are available.
The relay's separate SET and RESET circuits must be connected according to the manufacturer's wiring diagram. The correct control voltage, polarity and command arrangement are essential for reliable operation.
The Finder RB.14.9.250.0000 is not intended for direct operation from a 230 V AC control supply. Its specified control supply is DC, and an AC voltage must not be substituted without an appropriately designed interface.
Similarly, the relay should not be connected directly to a 24 V DC controller output. A corresponding lower-voltage RB Series variant should be selected where that is the available control supply.
Separate SET and RESET Controls with LED Indication
The Finder RB Series is designed to provide clear control of the relay's two stable positions.
The SET and RESET functions allow the relay to be commanded into either of its stable contact states. This is particularly useful where the control system requires an explicit command for each switching direction.
The relay also features LED command indication, providing a visual reference when a corresponding control signal is present.
This can help during commissioning and troubleshooting by allowing maintenance technicians to observe command activity at the relay assembly.
It is important to distinguish the presence of a control command from confirmation of the actual contact position. An illuminated command indicator does not independently prove that the contacts have switched successfully or that the connected equipment is operating.
Where confirmed switching status is required, a suitable feedback circuit or contact monitoring arrangement should be included in the control system.
35 mm DIN Rail Mounting for Industrial Control Panels
The Finder RB.14.9.250.0000 is supplied in a modular DIN rail mounting format.
It is designed for installation on a standard 35 mm DIN rail in accordance with EN 60715, allowing it to be integrated into industrial electrical cabinets alongside other control and protection components.
Its screw-terminal connections provide a practical wiring arrangement for the control supply and switching contacts.
DIN rail mounting is particularly useful for OEM electrical panel manufacturers and maintenance engineers working with standardised cabinet layouts.
The relay has an IP20 protection rating and should be installed within an enclosure that provides the protection required by the application.
Electrical isolation, conductor sizing, protective devices and appropriate segregation of circuits must all be considered during installation.
Designed for Industrial Control, Signalling and Power Applications
The Finder RB.14.9.250.0000 is particularly relevant to industrial systems requiring a defined switching state that remains established between commands.
Examples include power generation facilities, electrical distribution panels, industrial signalling systems and automated warehouses.
In an electrical distribution system, a bistable relay may be used to maintain an auxiliary switching or signalling state until an explicit command changes it.
In an automated warehouse or machinery control application, the relay can provide several coordinated contact outputs from a single bistable switching mechanism.
Because the contacts remain in their selected position without continuous coil energisation, the relay can also be useful where reducing continuous control power consumption is desirable.
However, the retained contact state must be considered during power restoration and equipment restart. A bistable relay may remain in its previous state after a supply interruption, so the overall control system must be designed to handle this behaviour safely.
Finder RB Series Voltage and Mounting Options
The Finder RB Series includes several bistable relay variants with different control voltages and contact configurations.
- Finder RB.14.9.024.0000: Four changeover contacts, 24 V DC supply, DIN rail mounting.
- Finder RB.14.9.048.0000: Four changeover contacts, 48 V DC supply, DIN rail mounting.
- Finder RB.14.9.125.0000: Four changeover contacts, 110–125 V DC supply, DIN rail mounting.
- Finder RB.14.9.250.0000: Four changeover contacts, 220–250 V DC supply, DIN rail mounting.
Other RB Series variants use a two-changeover-contact configuration and a compatible plug-in socket arrangement.
The RB.14.9.250.0000 should be selected where the application requires four changeover contacts and the specified higher-voltage DC control supply.
Different voltage variants are not interchangeable without confirming the control supply and electrical design.
Typical Applications
- Industrial automation control panels.
- Power generation facilities.
- Electrical distribution control systems.
- Industrial signalling circuits.
- Automatic warehouse equipment.
- Machinery control systems.
- Auxiliary switching circuits.
- Control state retention applications.
- Industrial process control installations.
- Electrical panel manufacturing.
- OEM control equipment.
- Multiple circuit changeover applications.
- Remote SET and RESET control systems.
- High-voltage DC auxiliary control installations.
- Replacement of compatible Finder RB Series bistable relays.
