MPX Magnetostrictive Level Sensors

1. Description

The MPX series magnetostrictive level sensor provides highly accurate and repeatable level readings for various liquid level measurement applications. It is CSA certified for hazardous areas (Class I, Division 1 & 2 and Class I, Zones 1 and 2 environments).

2. How To Read Your Label

Each sensor label includes a full model number, part number, and serial number. The model number, e.g., "MPX-R3-ZY-F2.5WB-120", details configurable options. Consult the datasheet for exact configuration. Hazardous certification information is also present on the label.

3. Warranty

APG offers a 24-month warranty against defects in material and workmanship under normal use. For full details, visit www.apgsensors.com/about-us/terms-conditions. Contact Technical Support for Return Material Authorization (RMA) before returning products.

4. Dimensions

MPX-E Chemical Housing Dimensions:

• 3/4" NPT and 1/2" NPT connections.
• Overall dimensions provided in inches (e.g., 5.94", 4.15", 2.13").
• Zero Reference point indicated.
• Ground Screw present.
• Note: Dual dimensions show large housing dimensions above small housing dimensions.

MPX-E Housing Dimensions:

• 3/4" NPT and 1/2" NPT connections.
• Overall dimensions provided in inches (e.g., 4.21", 3.74", 4.94").
• Zero Reference point indicated.
• Ground Screw present.
• Note: Dual dimensions show large housing dimensions above small housing dimensions.

MPX-R Housing Dimensions:

• 3/4" NPT connections.
• Overall dimensions provided in inches (e.g., 4.21", 4.94", 1.90").
• Zero Reference point indicated.
• Ground Screw present.
• Note: Dual dimensions show large housing dimensions above small housing dimensions.

[Important Warning: A seal must be installed within 18 inches of the enclosure.]

5. Installation Guidelines & Instructions

Environmental Conditions:

• Ambient temperature: -40°F to 185°F (-40°C to 85°C).
• Relative humidity: Up to 100%.
• Altitude: Up to 2000 meters (6560 feet).
• Pollution Degree: IEC-664-1, 1 or 2.
• Measurement Category: IEC 61010-1, II.
• Environment: Free from chemicals corrosive to stainless steel (e.g., NH3, SO2, Cl₂).
• Adequate space for maintenance.

Additional Precautions:

• Keep probe away from strong magnetic fields (motors, transformers, solenoid valves).
• Ensure the medium is free from metallic substances and foreign matter.
• Avoid excessive vibration.
• Verify floats fit through the mounting hole; if not, mount from inside the vessel.
• Ensure floats are oriented correctly on the stem (MPX-E floats factory-installed; MPX-R floats typically customer-installed).

Float Orientation:

[Important: Floats must be oriented properly on the stem for accurate readings. Untapered floats have a sticker or "N" indicating the top; remove sticker before use.]

Installation Instructions:

• If stem and floats fit mounting hole, lower assembly into vessel and secure.
• If floats do not fit, mount them on the stem from inside the vessel, then secure the sensor.
• For sensors with float stops, refer to the included assembly drawing.
• For MPX-E Chemical, ensure the probe is concentric with the fitting to avoid scraping the coating.

Electrical Installation Instructions:

• Remove housing cover.
• Feed wires through 3/4" NPT conduit openings (fittings must be UL/CSA Listed and IP65 rated or better).
• Connect wires to MPX terminals (use crimped ferrules if possible).
• Replace housing cover.
• For EMI protection on MPX-E4/R4 models, connect the grounding screw to earth ground or ensure tank mounting is grounded.

Refer to Section 6 for Modbus and 4-20 mA wiring examples.

6. Sensor and System Wiring Diagrams

Modbus System Wiring:

• Connect sensors in series using shielded cable.
• Use 120 Ω terminating resistors at the start and end of the bus.
• Connect to Server Device via RS-485 A/B.
• Earth Ground terminal is factory connected to internal housing ground lug.
• [Note: For APG Modbus programming, refer to the MPX user manual. APG Modbus software is available at www.apgsensors.com/support.]

Modbus System Wiring with RST-6001:

• Requires an independent +12-24 Vdc power supply for MPX sensors.
• RST-6001 provides ±5 Vdc, not sufficient for MPX.
• Connect via USB to computer with APG Modbus software.
• Use shielded cable with 120 Ω terminating resistors.
• Earth Ground terminal is factory connected to internal housing ground lug.

4-20 mA Wiring:

• Single Float Loop (MPX-E2/R2): Connect sensor output to receiver input, with power source (12-24 Vdc) and common.
• Dual Float Loop (MPX-E3/R3): Connect sensor outputs (Out 1, Out 2) to receiver inputs (Input 1, Input 2), with power source (12-24 Vdc) and common. Can also be wired to two separate receivers.

4-20 mA Programming Wiring:

• Requires RST-4100 Programming Module and APG Modbus software.
• Connect sensor to RST-4100 via USB.
• Use a load resistor (150 Ω to 700 Ω) wired in series for programming.
• Minimum 14 Vdc required for RST-4100 communication.
• [Note: Programming configuration is for programming only. Reintegrate sensor to 4-20 mA loop after programming.]

[Important: For EMI protection on MPX-E4/R4, connect grounding screw to earth ground or ensure tank mounting is grounded.]

[Important: MPX sensors must be installed per drawing 9003468 for listed approvals. Faulty installation invalidates safety ratings.]

7. General Care

The level sensor requires minimal maintenance if installed correctly. Periodically inspect the stem for buildup that could impede float movement. Sediment or foreign matter can cause detection errors. If removing floats, note their orientation for proper re-installation. Ensure the housing cover is securely fastened; order replacements if damaged or lost.

[Danger/Warning: Potential electrostatic charging hazard. Clean only with a damp cloth.]

8. Repair Information

For repairs, contact APG via email (sales@apgsensors.com), phone (888-525-7300), or online chat at www.apgsensors.com. An RMA number and instructions will be provided. [Important: All repairs and adjustments must be performed by the factory. Modification or disassembly is prohibited.]

9. Hazardous Location Wiring

General Warnings:

• [Danger/Warning: Explosion Hazard -- Substitution of components may impair suitability for Class I, Division 2.]
• [Danger/Warning: Explosion Hazard -- Do not disconnect equipment unless power is off or area is known to be non-hazardous.]
• [Danger/Warning: Open circuit before removing cover, or keep cover tight while circuits are alive.]
• [Danger/Warning: Potential electrostatic charging hazard. Clean only with a damp cloth.]

[Note: Refer to drawing 9003468 for Hazardous Installation and Non-Incendive Wiring.]