Introduction
This manual provides essential information for the safe and effective use of your D8 Latching Push Button Switch, Model MR-8VYK-BCFU-CA. Please read these instructions carefully before installation and operation to ensure proper functionality and safety.

Image: A D8 Latching Push Button Switch, featuring a red button and black threaded body, shown alongside a penny for size comparison. This illustrates the compact design of the switch.
Safety Information
WARNING: Electrical components can cause injury or death if not handled properly. Installation and wiring should be performed by qualified personnel or under the supervision of an experienced individual. Always disconnect power from the circuit before working with electrical components.
- Ensure the switch's electrical ratings (3 Amps, 250 Volts) are compatible with your specific application's voltage and current requirements.
- Avoid exposing the switch to moisture or extreme temperatures beyond its specified IP54 International Protection Rating.
- Do not attempt to modify or disassemble the switch. Unauthorized modifications may lead to malfunction or safety hazards.
- Keep the switch away from flammable materials during operation.
Package Contents
The standard package includes the following items:
- 4x D8 Latching Push Button Switches (Red, 3A 250V)
Specifications
| Feature | Specification |
|---|---|
| Brand | D8 |
| Model Number | MR-8VYK-BCFU-CA |
| Operation Mode | ON-NONE-OFF (Latching) |
| Current Rating | 3 Amps |
| Operating Voltage | 250 Volts |
| Actuator Type | Push Button |
| Controller Type | Push Button |
| Terminal Type | Button |
| Color | Red |
| Material | Copper |
| Mounting Type | Snap In Mount |
| International Protection Rating | IP54 |
| Product Dimensions (L x W x H) | 3.3 x 2.4 x 0.1 inches |
| Item Weight | 0.32 ounces |
Setup and Installation
Mounting the Switch
The D8 Latching Push Button Switch is designed for snap-in mounting into a panel or enclosure. Follow these steps for secure installation:
- Identify a suitable mounting hole on your panel. The hole diameter should match the threaded portion of the switch for a snug fit.
- Insert the threaded portion of the switch through the mounting hole from the front of the panel.
- Place the washer and then the hexagonal nut onto the threaded portion from the backside of the panel.
- Tighten the hexagonal nut firmly by hand or with an appropriate wrench. Avoid overtightening to prevent damage to the switch or panel.

Image: The individual components of the D8 Latching Push Button Switch, including the main switch body with its red button, a metal washer, and a hexagonal nut, laid out next to a penny for size reference. This illustrates the parts used for mounting.
Wiring the Switch
The switch features two terminals for electrical connection. Proper wiring is crucial for safe and correct operation.
- Before starting any wiring, ensure all power to the circuit is completely disconnected at the source.
- Connect the input power wire (e.g., from a power supply or circuit breaker) to one of the switch terminals.
- Connect the load wire (leading to the device or component you wish to control) to the other switch terminal.
- Ensure all electrical connections are secure, tight, and properly insulated to prevent short circuits or accidental contact.
- Once wiring is complete, carefully restore power to the circuit and test the switch's functionality.
Operating Instructions
The D8 Latching Push Button Switch operates with a simple ON-NONE-OFF mechanism:
- To turn ON: Press the red button once. The switch will engage and latch into the 'ON' position, completing the electrical circuit and powering the connected device. You will typically feel a distinct click and the button will remain depressed.
- To turn OFF: Press the red button again. The switch will disengage and return to the 'OFF' position, breaking the electrical circuit and turning off the connected device. The button will release and return to its original, un-depressed state.
Please note that this specific model does not feature an internal illumination to indicate its ON/OFF state. You should rely on the tactile feedback of the button (depressed for ON, released for OFF) or the operational status of the connected device.
Maintenance
The D8 Latching Push Button Switch is designed for durability and requires minimal maintenance to ensure long-term performance.
- Inspection: Periodically inspect the switch for any signs of physical damage, such as cracks in the housing, loose connections, or corrosion on the terminals.
- Cleaning: If necessary, clean the exterior of the switch with a dry, soft cloth. Do not use abrasive cleaners, solvents, or excessive moisture, as these can damage the switch or compromise its IP54 rating.
- Environmental Conditions: Ensure the operating environment remains within the specified IP54 rating, protecting against dust ingress and splashing water. Avoid prolonged exposure to harsh chemicals or extreme environmental conditions.
Troubleshooting
If you encounter issues with your D8 Latching Push Button Switch, consider the following troubleshooting steps:
Switch Does Not Operate
- No Power: Verify that power is being supplied to the circuit where the switch is installed. Check circuit breakers or power sources.
- Wiring Issues: Inspect all wiring connections to the switch and the connected load. Ensure they are secure, properly insulated, and correctly wired according to the circuit diagram.
- Incorrect Rating: Confirm that the switch's current and voltage ratings (3A, 250V) are appropriate for your application. Using the switch with incompatible electrical loads can prevent operation or cause damage.
- Faulty Load: Test the connected device or load independently to ensure it is functioning correctly and not causing the issue.
Intermittent Operation
- Loose Connections: Check for any loose wiring or terminals that might be causing intermittent contact.
- Debris/Obstruction: Inspect the button mechanism for any foreign objects or debris that might be preventing it from fully engaging or disengaging consistently.
- Environmental Factors: Ensure the switch is not exposed to conditions (e.g., excessive vibration, extreme temperature fluctuations) that could affect its mechanical operation.
Warranty and Support
For specific warranty information, return policies, or technical support regarding your D8 Latching Push Button Switch, please refer to the retailer or manufacturer's official website where the product was purchased. It is recommended to retain your purchase receipt as proof of purchase for any warranty claims.