ABB M063B

Description

Product Description

The ABB M063B is a specialized, current-powered, two-wire isolator and signal converter from ABB’s extensive range of measurement and automation components. This device is designed to provide galvanic isolation and signal conversion in a compact, loop-powered format. Its primary function is to accept a standard 4-20 mA input signal from a field transmitter and provide an isolated, precise 4-20 mA output signal, all while being powered entirely by the current loop itself—without requiring a separate auxiliary power supply. This makes the ABB M063B an ideal solution for breaking ground loops, providing intrinsic safety barriers, and protecting sensitive control system inputs from transients and noise. Its rugged design is suitable for installation in harsh industrial environments, often in field junction boxes or directly on DIN rails in control panels. The reliable performance of the ABB M063B is crucial for maintaining signal integrity in critical measurement and control loops.

Product Parameters

• Device Type: Two-wire Isolator / Signal Converter.
• Power Supply: Loop-powered; operates from the 4-20 mA signal (typically requires a minimum voltage drop, e.g., 2.5V).
• Input Signal: 4-20 mA.
• Output Signal: Isolated 4-20 mA.
• Isolation: High galvanic isolation between input and output (typically 1.5 kV or higher).
• Accuracy: High accuracy class (e.g., ±0.1% of span).
• Load Capacity: The output can drive a specific maximum load resistance (e.g., up to 500 Ω).
• Operating Temperature: Rated for standard industrial temperature ranges.
• Mounting: DIN-rail mounting (35mm).
• Housing: Compact, robust plastic or metal housing.
• Connections: Screw terminals for easy wiring.

Advantages and Features

• No External Power Required: The loop-powered design simplifies installation by eliminating the need for a separate 24V DC power supply, reducing wiring and cost.
• Ground Loop Elimination: The galvanic isolation provided by the ABB M063B effectively breaks ground loops, which are a common source of measurement error and signal instability.
• Intrinsic Safety (when certified): Certain versions can be used as intrinsic safety barriers, allowing connection of field devices from hazardous areas to safe-area control systems.
• Compact and Rugged: Its small size and robust construction make it suitable for installation in space-constrained and demanding environments.
• Easy Installation: Simple screw terminal connections and DIN-rail mounting allow for quick and easy installation and maintenance.

Application Cases in Application Fields

• Chemical Processing: Isolates 4-20 mA signals from pressure or temperature transmitters located in hazardous areas before they enter the safe-area DCS, preventing ground loops and providing protection.
• Water and Wastewater Treatment: Used to isolate signals from submerged pumps or sensors in wet environments, protecting the SCADA system from lightning-induced surges.
• Oil & Gas Field Instrumentation: Installed in field junction boxes to condition and isolate signals from wellhead pressure and temperature transmitters over long cable runs.
• Power Generation: Isolates signals from boiler instrumentation to protect the DCS from high-voltage transients.

Comparisons with Competing Products

• Vs. Four-wire Isolators (e.g., ABB SCYC series): Four-wire isolators require a separate power supply but often offer higher accuracy and can perform signal conversion (e.g., 4-20mA to 0-10V). The ABB M063B is chosen for its simplicity and lack of external power needs in applications where only isolation is required.
• Vs. Pepperl+Fuchs or Phoenix Contact Loop Isolators: Competing brands offer similar two-wire isolators. The ABB M063B competes on brand reputation, specific accuracy specifications, and potentially better integration within facilities standardized on ABB equipment.
• Vs. PLC with Isolated Analog Input Cards: Using an isolated input card integrates the function but is less flexible. The ABB M063B can be placed closer to the field sensor to break the ground loop at the source, whereas an isolated card only breaks it at the PLC.

Selection Suggestions and Precautions

1. Verify Loop Voltage Compliance: Ensure the voltage available in the current loop (at the transmitter and after accounting for wire resistance) is sufficient to power the ABB M063B and still drive the required load on the output side. The device has a minimum operating voltage.
2. Calculate Total Loop Load: The ABB M063B, the transmitter, and the receiving device (PLC input) all present a load. The total resistance of the loop must be within the compliance voltage range of the transmitter. The output load capacity of the isolator must not be exceeded.
3. Correct Wiring: Adhere strictly to the input and output terminals. Incorrect wiring will prevent operation. Use shielded twisted-pair cable and ground the shield at one end only.
4. Use in Intrinsically Safe Loops: If used for intrinsic safety, ensure the specific ABB M063B model is certified (e.g., ATEX, IECEx) for the required zone and is correctly installed as per the safety documentation.
5. Environmental Suitability: While industrially rated, ensure the ambient temperature at the installation location is within the specified operating range to maintain accuracy and longevity.

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