Madison M8000 Liquid Level Sensor Instruction Manual

Introduction

This manual provides detailed instructions for the installation, operation, and maintenance of the Madison M8000 Miniature Vertical Float Switch. The M8000 is designed to detect high or low liquid levels in various containers. Constructed from polypropylene, it is suitable for food material handling, agriculture, and contact with many industrial fluids, including low-temperature food equipment applications up to 221°F (105°C).

Installation and Setup

Mounting

The Madison M8000 features a 1/8" NPT (National Pipe Thread) connection for mounting. NPT connections are tapered and designed to create a seal by tightening into a corresponding female NPT threaded port. This switch does not utilize a separate nut for mounting. It is intended to be threaded directly into a pre-tapped 1/8" NPT hole in the application's tank or device.

When installing, apply an appropriate thread sealant, such as PTFE tape, to the NPT threads of the sensor. Carefully thread the sensor into the female NPT port until hand-tight, then use a wrench on the hexagonal portion of the stem to tighten further, ensuring a secure and leak-free connection. Avoid overtightening to prevent damage to the sensor or the mounting port.

For applications requiring custom tank depths, the NPT vertical switch can be extended using compatible piping.

Wiring

The M8000 is equipped with 24", 22 AWG, MTW insulated lead wires. The switch is rated for resistive loads and operates as a Single Pole, Single Throw (SPST) switch. It can be configured for Normally Open (NO) or Normally Closed (NC) operation depending on the orientation of the float. Consult the electrical specifications for appropriate voltage and current ratings.

• Electrical Ratings: 240 VAC, 0.14A; 120 VAC, 0.28A; 120 VDC, 0.07A; 24 VDC, 0.28A
• Switch Rating: 30 Watt, SPST
• Important: Switches are rated for resistive loads. For inductive loads, it is recommended to use an isolation control relay to protect the switch contacts and ensure longevity. Avoid placing the magnetic reed type float switch near strong interfering magnetic fields.

Operation

The Madison M8000 operates as a simple float switch. As the liquid level rises or falls, the polypropylene float moves along the stem. When the float reaches a predetermined position, it actuates an internal reed switch, changing its electrical state (either opening or closing a circuit). This change in state can be used to trigger alarms, control pumps, or activate other equipment.

The switch can be oriented to detect either high or low levels. The float's position on the stem determines the activation point. Ensure the float moves freely without obstruction within the liquid.

Maintenance

The Madison M8000 is designed for minimal maintenance. Regular inspection is recommended to ensure optimal performance:

• Cleaning: Periodically inspect the float and stem for any buildup or debris that might impede its free movement. Clean with a mild detergent and water if necessary. Avoid abrasive cleaners.
• Wiring: Check lead wires for any signs of wear, damage, or corrosion. Ensure all electrical connections are secure.
• Mounting: Verify that the sensor remains securely mounted and that there are no leaks around the NPT connection.
• Functionality Test: If possible, periodically test the switch's operation by manually raising or lowering the liquid level to confirm it actuates correctly.

Troubleshooting

• Sensor Not Actuating:
  • Check for obstructions preventing the float from moving freely.
  • Verify correct wiring and electrical connections.
  • Ensure the liquid level reaches the activation point of the float.
  • Confirm the electrical load is within the specified resistive ratings. If using an inductive load, ensure an isolation relay is properly installed.
  • Check for strong external magnetic fields that might interfere with the internal reed switch.
• Intermittent Operation:
  • Inspect for debris on the float or stem causing inconsistent movement.
  • Check for loose wiring connections.
  • Ensure the liquid is not excessively turbulent, which could cause rapid float movement.
• Leaks at Mounting Point:
  • Ensure adequate thread sealant (e.g., PTFE tape) was used during installation.
  • Verify the sensor is properly tightened into the NPT port.
  • Inspect the NPT threads on both the sensor and the mounting port for damage.

Specifications

Product Images

Warranty and Support

Specific warranty information and direct support contact details for the Madison M8000 Liquid Level Sensor were not provided in the product data. For warranty claims or technical assistance, please refer to the official Madison Company website or contact your authorized distributor.