Why Choose the Finder 99.01.9.024.90 LED and Diode Module?
The Finder 99.01.9.024.90 is a compact red LED indication and flyback diode suppression module designed for compatible Finder relay sockets. Part of the Finder 99 Series, it combines visual relay coil indication with electrical transient suppression in a convenient plug-in accessory for industrial automation and control panel applications.
Designed for 6–24 V DC relay coil circuits, the module features a red LED that illuminates when the relay coil is energised. This provides an immediate visual indication of the control signal, helping electrical engineers and maintenance technicians identify active relays during commissioning, inspection and fault-finding.
The integrated freewheeling diode helps suppress the reverse-voltage spike generated when a DC relay coil is switched off. By providing a discharge path for the coil's stored magnetic energy, the diode helps reduce electrical transients that could otherwise interfere with sensitive electronic control equipment.
The Finder 99.01.9.024.90 uses standard polarity, with the positive supply connected to terminal A1. Its compact blue housing and plug-in construction make it a practical accessory for compatible Finder relay installations where both coil indication and DC suppression are required.
Key Advantages
- Dual-function module combines LED coil indication and diode suppression.
- Red LED indicator provides visible confirmation of relay coil energisation.
- 6–24 V DC operating range supports common low-voltage control circuits.
- Integrated flyback diode helps suppress inductive voltage spikes.
- Standard polarity configuration with positive connected to terminal A1.
- Helps protect associated electronic circuitry from relay coil switching transients.
- Plug-in construction simplifies installation in compatible relay sockets.
- Compact module design avoids the need for separate LED and diode components.
- Useful for commissioning and diagnostics through visual coil status indication.
- Suitable for PLC-controlled relay circuits with compatible DC outputs.
- Supports organised control panel wiring and maintenance.
- Finder 99 Series accessory for compatible industrial relay assemblies.
Key Features
- Finder 99 Series relay accessory.
- Manufacturer part number: 99.01.9.024.90.
- 99.01 plug-in module format.
- Red LED coil status indication.
- Integrated freewheeling diode.
- DC relay coil transient suppression.
- 6–24 V DC operating voltage range.
- Standard polarity arrangement.
- Positive connection to relay coil terminal A1.
- LED illuminates when the coil is energised.
- Blue insulating module housing.
- Plug-in installation in compatible Finder sockets.
- Suitable for industrial switching relay accessories.
- Helps reduce electromagnetic interference associated with coil de-energisation.
- Approximately threefold increase in relay release time compared with an unsuppressed coil, depending on the relay and circuit.
- RoHS compliant.
- Suitable for low-voltage DC automation circuits.
Technical Specifications
- Manufacturer: Finder
- Series: 99 Series
- Module family: 99.01
- Model: 99.01.9.024.90
- Product type: Plug-in LED indication and diode suppression module
- Accessory classification: Relay coil indication and EMC suppression module
- Indication type: LED
- LED colour: Red
- Suppression component: Freewheeling diode
- Operating voltage range: 6–24 V DC
- Supply type: DC
- Polarity: Standard polarity
- Positive connection: A1
- Negative connection: A2
- Suppression function: Relay coil reverse-voltage suppression
- LED operation: Illuminates when the relay coil is energised
- Relay release-time effect: Approximately 3 times the unsuppressed release time
- Installation method: Plug-in connection to compatible Finder relay socket
- Module housing colour: Blue
- Compatible socket format: Selected Finder sockets accepting 99.01 modules
- Compatible relay type: Suitable DC-coil switching relays installed in compatible sockets
- RoHS compliance: Compliant
- Product weight: Approximately 2 g
- Relay included: No
- Relay socket included: No
How LED Indication and Flyback Diode Suppression Work Together
When a DC relay coil is energised, current flows through its winding and generates the magnetic field needed to operate the relay contacts. The Finder 99.01.9.024.90 provides a red LED indication during this energised state, allowing operators to see that the coil supply is present without using a separate indicator lamp.
When the control voltage is removed, the magnetic field stored in the relay coil begins to collapse. Without suppression, this process can generate a reverse-voltage spike across the coil terminals. The module's integrated freewheeling diode provides a controlled current path that limits this voltage spike and helps reduce interference with connected electronic equipment.
The diode also affects how quickly the relay releases. Because the stored coil energy is dissipated through the freewheeling path, the relay's release time can increase by approximately a factor of three. This characteristic should be considered in applications requiring rapid relay release, precise switching sequences or safety-related timing performance.
Correct polarity is essential. The Finder 99.01.9.024.90 is a standard-polarity module intended for circuits with positive connected to A1 and negative connected to A2. Reversing the supply may forward-bias the suppression diode and cause excessive current. The module should only be installed after checking the relay coil voltage, socket compatibility and wiring polarity.
The 99.01 plug-in format allows the module to be installed in suitable Finder relay sockets without constructing a separate diode and LED circuit. This makes it useful for control panel manufacturing, equipment upgrades and maintenance where clear relay status indication and coil transient suppression are required.
Typical Applications
- Industrial automation and DC relay control circuits.
- PLC output interfaces controlling compatible relay coils.
- Electrical control cabinets and relay panels.
- Machine control and auxiliary switching systems.
- Relay coil status indication during commissioning.
- Suppression of inductive voltage spikes in DC control circuits.
- Industrial process control and instrumentation.
- Equipment diagnostics and fault-finding.
- Conveyor and material handling control systems.
- OEM electrical equipment manufacturing.
- Maintenance of compatible Finder relay assemblies.
- Low-voltage DC control systems requiring visual indication and coil suppression.
