GSI127 244-127-000-017 A2-B05 Galvanic Separation Unit

The GSI127 244-127-000-017 A2-B05 is a high-performance galvanic isolation unit, specifically designed and certified for use in potentially explosive atmospheres (hazardous areas). This product plays a critical role in industrial monitoring and control systems. Its primary functions are to supply power to sensors and their signal conditioners and to provide electrical isolation between the sensor side and the monitor side, ensuring safety, stability, and noise immunity in signal transmission.

A breakdown of the model number "244-127-000-017 A2-B05" is as follows:

• A2: Indicates the unit is an Ex-approved version for hazardous areas.

• B05: Specifies its transfer characteristic as an inverting voltage-to-voltage conversion, with a sensitivity of -1 V/V and an output offset of 10 VDC. This configuration is optimized for use with IQSxxx series signal conditioners or the VE210 velocity sensor that have a voltage output signal for transmission over shorter distances.

Acting as a bridge between field sensors and backend monitoring systems, the GSI127 unit effectively addresses issues such as signal attenuation over long distances, ground loop interference, and safety isolation in explosive environments. It is a core component in highly reliable measurement chains within critical industrial sectors like oil & gas, power generation, and chemicals.

2. Core Design and Features

1. Powerful Galvanic Isolation

• Sensor Side to Monitor Side Isolation: Provides reinforced isolation up to 4 kV RMS, completely breaking the electrical connection between the two sides. This prevents high-voltage transients and protects valuable monitoring equipment.

• Power Supply to Output Signal Isolation: The output signal features a floating output design, providing 50 V RMS of isolation from the power supply. This eliminates the need for additional external isolation power supplies (e.g., APF19x series), simplifies system architecture, and further suppresses common-mode noise.

2. Exceptional Noise Immunity

• High Common-Mode Voltage Rejection: The internal design significantly rejects "frame voltage" – the ground noise and AC induction noise that can exist between the sensor case (sensor ground) and the monitoring system (electronic ground). This greatly reduces background noise in the measurement chain, improving signal-to-noise ratio and measurement accuracy.

• Excellent Power Supply Rejection Ratio (PSRR): ≥60 dB from 10 Hz to 400 Hz, and ≥30 dB from 400 Hz to 100 kHz, ensuring the output signal remains unaffected by power supply fluctuations or noise.

3. Versatile Signal Conditioning & Transmission

• Supports Current & Voltage Signal Modes: The flexible design allows for both long-distance current-signal transmission (e.g., 4-20 mA) via its µA-to-mV transfer function, and short-distance voltage-signal transmission. The B05 configuration is specifically optimized for inverting 1:1 voltage signal transfer.

• Wide Bandwidth & High Linearity: Signal transmission bandwidth is DC to 20 kHz (within ±0.5 dB), with a typical -3 dB cutoff frequency of 30 kHz, meeting the requirements for transmitting most dynamic signals like vibration and pressure. Linearity is better than 0.2%, ensuring true signal reproduction.

• Low Drift & Low Noise: Output offset drift with temperature is ≤2 mV/°C, and sensitivity drift with temperature is ≤50 ppm/°C. AC output signal residual noise is ≤3.5 µV_RMS/√Hz, guaranteeing long-term stability and high precision in harsh industrial environments.

4. Intrinsic Safety & Explosion Protection Certification

• Multi-Country/Region Ex Certifications: The A2 version holds comprehensive certifications for explosive atmospheres (Zone 2 / Division 2), including:

• Europe (ATEX): II 3 (1) G Ex nA [Ia Ga] IIC T4 Gc

• International (IECEx): Ex nA [Ia Ga] IIC T4 Gc

• North America (cCSAus): Class I, Division 2, Groups A,B,C,D & Class I, Zone 2 AEx nA [Ia Ga] IIC T4 Gc

• UK (UKEX), South Korea (KGS), Russia/Eurasian Union (EAЭC), and others.

• Simplified Safety Design: When used in intrinsic safety (Ex i) applications, the unit can eliminate the need for additional external Zener barriers, reducing system complexity and cost.

5. Wide Compatibility

• Perfect Integration with vibro-meter® Product Line: Seamlessly works with IPC707/704 signal conditioners (charge amplifiers) for CAxxx piezoelectric accelerometers and CPxxx dynamic pressure sensors, IQS9xx/4xx signal conditioners for TQ9xx proximity probes, CExxx piezoelectric accelerometers, and the VE210 velocity sensor.

• Compatible with Industry-Standard IEPE Sensors: Supports Integrated Electronics Piezo Electric (IEPE) vibration sensors with constant-current supply and voltage output, such as CE620 and PV660, enhancing its applicability in general vibration monitoring.

6. Easy Installation & Maintenance

• Removable Screw-Terminal Connectors: The terminal blocks for I/O signals can be unplugged from the main unit body, allowing pre-wiring in confined spaces and greatly simplifying installation and future maintenance.

• Standard DIN-Rail Mounting: Equipped with an adaptor for direct mounting on standard TH 35 type DIN rails (e.g., TH 35-7.5 or TH 35-15) compliant with EN 50022 / IEC 60715, enabling easy integration into control cabinets or junction boxes.

• No Dedicated Ground Connection Required: Its floating output and internal isolation design mean it typically requires no dedicated ground connection in most applications, further simplifying wiring.

  
  

3. Application Areas

Due to its high isolation, explosion safety, and excellent signal integrity, the GSI127 244-127-000-017 A2-B05 galvanic isolation unit is primarily used in the following fields where reliability and safety are paramount:

1. Oil, Gas & Petrochemical Industry: Used in vibration, displacement, and pressure monitoring systems for rotating equipment (compressors, pumps, gas turbines) on offshore platforms, in refineries, and along pipelines, ensuring safe and continuous operation in potentially explosive gas atmospheres.

2. Power Generation Industry: Especially in online Condition Monitoring and Protection Systems (CMS) for gas turbines, steam turbines, wind turbines, and large pumps/boiler feed pumps, helping to prevent catastrophic failures and enabling predictive maintenance.

3. Chemical & Pharmaceutical Industry: For safe monitoring of critical equipment like mixers, reactors, and centrifuges in process environments with flammable dust or vapors.

4. Safety-Related Applications: As part of Safety Instrumented Systems (SIS) or critical protection chains, providing reliable, isolated sensor signals for safety interlocks.

The B05 configuration is particularly suited for applications where the sensor or pre-conditioner provides a voltage output signal and transmission distances are relatively short. Examples include monitoring shaft displacement or differential expansion using IQS proximity probe systems, or monitoring bearing housing vibration with a VE210 velocity sensor, and safely delivering the signal to a monitoring system or PLC/DCS located in a safe area.

4. Product Advantages Summary

1. Safe & Reliable: Globally recognized explosion protection certifications and 4 kV isolation capability provide the highest level of safety for personnel and equipment in hazardous areas.

2. Outstanding Performance: Wide bandwidth, high linearity, low noise, and low drift ensure high-fidelity measurement signals, forming the foundation for accurate condition analysis and fault diagnosis.

3. System Simplification: Integrates power supply, signal isolation, and noise rejection into one unit, eliminating the need for extra isolation supplies or safety barriers. This reduces system complexity, cost, and installation space.

4. Flexible & Compatible: Broadly compatible with the vibro-meter® line and industry-standard IEPE sensors. A single hardware platform can address multiple applications through different configurations (B codes), reducing spare part variety.

5. Easy Installation: DIN-rail mounting and removable terminal design greatly facilitate system integration, wiring, and subsequent maintenance.

6. Global Service & Support: Backed by Meggitt's worldwide network, customers receive timely technical support, certification documentation, and after-sales service.