Epro A6370D Overspeed Protection Monitor

Product Description

The A6370D overspeed protection module, part of the AMS 6300 Safety Instrumented System from Emerson Electric, is engineered for high-integrity speed monitoring and shutdown protection in critical rotating equipment. It is designed to detect overspeed conditions with high precision and initiate protective actions to prevent mechanical failure or catastrophic damage.

Installed within a 19-inch rack system alongside the A6371 backplane, the A6370D operates as part of a redundant architecture. It processes signals from multiple sensor types and delivers fast, deterministic response suitable for SIL 3 safety applications in turbomachinery environments.

System Architecture and Functionality

• Part of AMS 6300 SIS with modular rack-based design

• Supports redundant configurations for high availability

• Real-time speed monitoring with configurable trip thresholds

• Compatible with eddy-current, Hall-effect, and VR sensors

• Designed for safety-critical shutdown systems

Technical Specifications

General Information

• Model: A6370D

• Product Type: Overspeed Protection Monitor

• System Platform: AMS 6300 SIS (requires A6371 backplane)

• Mounting: 19" rack, 84 HP width, 3 RU height

• Functional Safety: SIL 3 compliant (IEC 61508), TÜV certified

• Origin: Germany / USA

Power Supply

• Supply Voltage: 24 V DC (nominal system input)

• Sensor Supply: –24.5 V DC ±1.5 V

• Isolation: Galvanically isolated, short-circuit protected

• Maximum Sensor Current: 35 mA

Sensor Input Interfaces

Eddy Current and Hall-Effect Sensors

• Input Range: 0 to 26 V (bidirectional)

• Protection Limit: ±48 V

• Frequency Range: 0 to 20 kHz

• Input Impedance: Approx. 100 kΩ

Magnetic (VR) Sensors

• Input Signal: Minimum 1 Vpp, maximum 30 V RMS

• Frequency Range: 0 to 20 kHz

• Input Impedance: Approx. 18 kΩ

Speed Measurement Performance

• Configurable Overspeed Setpoint: 3,000 to 10,000 RPM

• Supported Speed Range: 0 to 100,000 RPM

• Measurement Accuracy: ±0.05% of full scale

• Response Time:

• ~35 ms (single pulse per revolution)

• ~12.5 ms (automatic mode)

• Typical: measurement time + 8 ms

• At 3,000 RPM:

Input/Output Interfaces

Digital Inputs (Backplane)

• Quantity: 4 (galvanically isolated)

• Logic Low: 0 to 5 V

• Logic High: 13 to 31 V

• Input Resistance: Approx. 6.8 kΩ

Analog Outputs (Backplane)

• Quantity: 2 (isolated)

• Signal Range: 0/4–20 mA or inverted 20–4/0 mA

• Accuracy: ±1% full scale

• Maximum Load: <500 Ω

Digital Outputs

• Quantity: 7 (short-circuit protected)

• Logic Low: <100 mV

• Logic High: –2 V

• Maximum Output Current: 25 mA

Pulse Outputs

• Backplane Outputs: 3 channels (max 31.2 V, 16 mA at 24 V)

• Front Output: 1 TTL signal (0–5 V), frequency up to 20 kHz

Communication Interfaces

• USB Type-B: Local configuration

• RS-485: Multi-drop network, up to 32 devices, 38.4–115.2 kbps

• PROFIBUS-DP (A6370D/DP variant): Up to 12 Mbit/s, 31 nodes

Environmental Conditions

• Operating Temperature: –20 °C to +65 °C

• Extended Range (variant-dependent): –40 °C to +85 °C

• Protection Rating: IP20 (rack-installed), IP00 otherwise

System Configuration Notes

A complete AMS 6300 SIS setup typically includes:

• Three A6370D protection monitors

• One A6371 system backplane
  This architecture enables redundant signal processing and ensures compliance with safety integrity requirements.

Application Areas

The A6370D is deployed in safety-critical applications where overspeed protection is essential:

• Steam and gas turbines

• Compressors and expanders

• Power generators

• Test stands and engine systems

• High-speed rotating machinery in process industries

FAQ

Q: What types of sensors can be connected?
A: The module supports eddy-current probes, Hall-effect sensors, and magnetic (VR) sensors.

Q: Is the system suitable for safety-critical applications?
A: Yes, it is SIL 3 certified and designed for use in safety instrumented systems.

Q: How fast does the module respond to overspeed conditions?
A: Response time depends on operating mode but can be as low as approximately 12.5 ms under typical conditions.

Q: Can the module be integrated into industrial networks?
A: Yes, it supports RS-485 and optional PROFIBUS-DP communication for system integration.