GF 3-9900-394 Signet Power Output Module

I. Product Overview

The GF 3-9900-394 is a dedicated power supply and isolated analog output module within the GF Signet 3-9900 modular transmitter series. It is a core plug-in module designed for installation on the back of 3-9900 series transmitter main units (such as the 3-9900-01). Its primary function is to provide operating power for the complete transmitter system while delivering dual-channel, highly reliable 4-20mA analog output signals. This module is ideal for applications that require stable power and the transmission of process variable signals to control systems like PLCs or DCSs.

II. Core Functions & Positioning

This module is an essential component for building a functional 3-9900 transmitter system. Its core roles are:

1. System Power Supply: It provides the necessary isolated DC power for the transmitter main unit and its connected two-wire 4-20mA sensors.

2. Isolated Analog Signal Output: It generates two fully independent, isolated 4-20mA current output signals. These signals are proportional to the process variables measured by the connected sensors (e.g., flow rate, pH, conductivity) and are used for transmission to external control and monitoring equipment.

In simple terms: 3-9900-394 = Power Supply + Dual Isolated 4-20mA Outputs.

III. Core Advantages & Features

1. Dual Isolated 4-20mA Outputs:

◦ Provides two independent 4-20mA channels, allowing the transmission of two different parameters (e.g., flow rate and temperature, if configured) or the same parameter to two different receiving devices.

◦ Electrical isolation between channels and from the power supply prevents ground loops and minimizes signal interference, ensuring signal integrity and system reliability.

2. Wide-Range AC Power Input: Accepts 85-265 VAC, 50/60Hz, making it suitable for global power standards and robust against voltage fluctuations.

3. Hot-Swappable Design: Like all 3-9900 series modules, it can be inserted or removed without powering down the system, ensuring maintenance and reconfiguration without process interruption.

4. Compact & Integrated: Combines power conversion and high-performance analog output circuitry into a single, space-saving module, simplifying system assembly and wiring.

5. High Compatibility: Works seamlessly with all 3-9900 series main units and any input module (e.g., 3-9901-F1 for flow, 3-9901-P1 for pH), enabling quick configuration of complete transmitters for various measurements.

6. Robust & Reliable: Designed for industrial environments, offering stable performance in demanding conditions.

IV. System Configuration & Application

A typical 3-9900 transmitter system using the -394 module includes:

• Main Unit: GF 3-9900-01 (Display & Processor)

• Input Module: e.g., 3-9901-F1 (Flow), 3-9901-P1 (pH), 3-9901-C1 (Conductivity)

• Power/Output Module: GF 3-9900-394 (Power + Dual 4-20mA)

• Sensor: Corresponding GF Signet sensor

Application Scenarios:

This module is perfect for applications requiring local display and analog signal transmission to a control room or recorder.

• Pump Control & Monitoring: Transmitting flow and pressure signals to a PLC for control logic.

• Chemical Dosing Systems: Sending pH or ORP signals to a controller for precise reagent addition.

• Water Quality Monitoring: Transmitting conductivity or temperature readings from a treatment skid to a central SCADA system.

• Industrial Process Loops: Providing process variable feedback (e.g., flow, level, temperature) for DCS-controlled loops.

V. Main Technical Specifications

• Power Input: 85 - 265 VAC, 50/60 Hz

• Analog Output: Two channels, isolated 4-20mA

• Output Load: Typically up to 600 Ω per channel (compatible with most PLC/DCS inputs)

• Isolation: Channel-to-channel and channel-to-power isolation

• Installation: Plug-in module for 3-9900 series main units

• Compatibility: Fully compatible with all GF 3-9900 series main units and input modules

VI. Important Notes & Comparison

• The GF 3-9900-394 is a module and requires a 3-9900 main unit and an input module to form a complete transmitter.

• Key Selection Guide:

◦ Choose 3-9900-394 when you need dual 4-20mA analog outputs and AC power.

◦ Choose 3-9900-391 for a similar configuration but potentially with different specifications (verify datasheet).

◦ Choose 3-9900-393 when Modbus RTU digital communication (RS-485) is required instead of or in addition to analog outputs.

◦ Choose 3-9900-392 when relay contact outputs are needed for alarm or control functions.

• Always consult the official GF Signet datasheet for the most accurate and detailed specifications before selection and ordering.

Keywords: GF 3-9900-394, Signet power module, isolated 4-20mA output module, dual analog output, 3-9900 series module, GF Signet transmitter accessory, process control signal transmission.