ARM15A-000 | Yokogawa | 32-Channel Mechanical Relay Input Board

Product Overview

The ARM15A-000 mechanical relay board from Yokogawa Electric Corporation is a 32-channel dry contact input interface designed for CENTUM VP distributed control systems. It provides galvanic isolation between field-side contact signals and digital input modules, improving signal integrity and system safety in demanding process environments.

This relay board is engineered for direct mounting in 19-inch control racks and interfaces seamlessly with Yokogawa FIO subsystems using supported digital input modules.

System Compatibility

The ARM15A-000 is specifically designed for use with Yokogawa digital input modules and associated system cables:

• ADV151 Digital Input Module using AKB331 cable
• ADV161 Digital Input Module using AKB337 cable
• Fully supported within CENTUM VP FIO architectures

Electrical and Functional Characteristics

Each of the 32 channels accepts dry contact signals and performs relay-based isolation before passing the status to the control module. Relay isolation ensures effective protection against ground loops, noise, and voltage transients commonly encountered in industrial field wiring.

Input state recognition is optimized for reliable contact sensing:

• ON condition detected at contact resistance ≤ 150 Ω
• OFF condition detected at contact resistance ≥ 200 kΩ

Power Supply Design

The board incorporates a dedicated internal 24 VDC supply for relay operation, rated at approximately 0.32 A. In addition, field-side power is provided through dual independent 24 VDC inputs, each supplying 16 channels. This configuration supports both single and dual-redundant power schemes.

Integrated protection functions include overcurrent, overvoltage, and reverse polarity protection. Power and channel status are continuously indicated via onboard LEDs.

Mechanical Construction

The ARM15A-000 is built for control room installation and long-term operation:

• 19-inch rack mountable, 3U height
• Transparent protective terminal cover
• Removable screw terminal blocks for simplified wiring and maintenance
• Robust metal chassis suitable for continuous industrial duty

Technical Specifications

• Model: ARM15A-000
• Product Category: Mechanical Relay Input Board
• Number of Input Channels: 32 dry contact inputs
• Relay Type: Mechanical isolation relays
• Field Power Supply: Dual 24 VDC inputs, up to 0.3 A per channel
• Internal Power Supply: 24 VDC, approx. 320 mA
• Input Detection Thresholds: ON ≤ 150 Ω, OFF ≥ 200 kΩ
• Insulation Resistance: ≥ 10 MΩ at 500 VDC
• Channel Indication: Individual LED indicators
• Terminal Type: M4 screw terminals
• Operating Temperature: 0 to 50 °C
• Operating Humidity: 10–90% RH, non-condensing
• Mounting: 19-inch rack, 3U
• Dimensions: 482.6 mm × 132.5 mm × 138 mm
• Weight: 2.2 kg

Typical Applications

• Digital input isolation in oil and gas processing units
• Alarm and interlock signal interfacing in power plants
• Dry contact monitoring for safety and auxiliary systems
• Field signal conditioning in chemical and petrochemical facilities

Frequently Asked Questions

Q: Does the ARM15A-000 support redundant power input? A: Yes. The board supports dual 24 VDC field power inputs, each serving 16 channels, allowing redundant power configurations.

Q: Is this board compatible with non-Yokogawa DCS systems? A: The ARM15A-000 is designed exclusively for Yokogawa CENTUM VP systems and is not recommended for third-party DCS platforms.

Q: What type of signals can be connected? A: The board is intended for dry contact (potential-free) inputs only.