The Emerson EPRO A6312-8 Speed and Key Monitor is designed for high reliability in monitoring the speed, phase, zero speed, and direction of rotation for critical rotating machinery in industrial plants. This 1-slot monitor is used in conjunction with AMS 6500 monitors to create a comprehensive API 670 machinery protection monitor. Its applications include monitoring steam, gas compressors, and hydro turbine machinery.

The Speed and Key Monitor can be configured for redundant mode, enabling automatic switchover from primary to backup tachometers. Sensor gap voltage and pulse counting/comparison are monitored to trigger switchover. When operating in redundant mode, the main and failover key or speed displacement sensor must be installed in the same axial plane to ensure phase continuity upon failover.

Key Features

• Two-channel 3U size plug-in modules reduce cabinet space requirements by half compared to traditional four-channel 6U size cards.
• API 670 compliant, hot-swappable module.
• Remote selectable limit multiply and trip bypass.
• Rear buffered proportional outputs, 0/4-20 mA output.
• Self-checking facilities include monitoring hardware, power input, hardware temperature, sensor, and cable.
• Compatible with displacement sensors 6422, 6423, 6424, and 6425 and driver CON011/91, 021/91, 041/91.
• Available in 6TE wide module for AMS 6000 19” rack mount chassis and 8TE wide module for AMS 6500 19” rack mount chassis.

Transducer Inputs

• Number of Inputs: Two, independent.
• Type of Inputs: Eddy current, differential.
• Emerson Sensor Inputs: Part number: 6422, 6423, 6424, 6425.
• Isolation: Galvanically separated from power supply.
• Input Resistance: >100 kΩ.
• Input Voltage Range: 0 to ±27.3 VDC.
• Input Frequency Range: 0 – 20,000 Hz, 65,535 RPM.

Measuring Range

• Range: Continuously adjustable with the configuration software.
• Smallest Range: 2 V.
• Largest Range: 0 – 30 V.
• Sensor Power Supply: Separate buffered sensor supply, galvanically separated from all system voltages and system supply voltage, open and short circuit proof.
• Nominal Voltage: -26.75 VDC.
• Available Current: Nominal 20 mA, maximum 35 mA.

Front Panel Outputs

• Green LED’s: Two LED’s, indicates channel OK separately for each channel.
• Yellow LED’s: Four LED’s, indicates alert and danger separately for each channel.
• Front Panel Buffered Outputs: Two, ±10 V, signal input level reduced by factor 0.15, >100 kΩ load, frequency range 0 Hz – 16 kHz (-3 dB).
• Mini DIN Configuration Socket: Module interface connection for configuration and parameter and status monitoring, RS-232.
• Handle: Easily remove card and provide a plate for module and sensor identification.

Analysis

• Measurement Modes: Hot configurable.
• Speed Measurements with Each Channel: Forward and reverse rotation with trigger wheel (1 – 255 trigger marks), max. freq. 20 kHz.
• Pulse Width Time Window: 5 – 10 msec.
• Key Pulse Detection with Each Channel: One key mark on the shaft, possible with multiple key marks, but phase will change with each start-up.
• Zero Speed Monitor with Each Channel: Detects zero speed of trigger wheel with 1 – 255 trigger marks, measures time between two pulses in a configurable range of 1 – 1700 seconds, forward or reverse direction.
• Both Channels in Combined Use: Detects direction of rotation of two trigger marks of which one is phase shifted, detects a difference between the speed of two trigger wheels, difference adjustable in number of RPM.

Rear Outputs Available

• Current Mode Outputs: 0/4-20 mA output for each channel proportional to main value, open/short circuit proof, permissible load <500 Ω, accuracy ±1% of full scale, configurable settling time 0 – 10 seconds.
• Pulse Outputs: 0 Hz – 20 kHz output for each channel, open/short circuit proof, permissible load >10 kΩ.
• TTL Pulse Output: 0 Hz – 20 kHz output signal for each channel, open/short circuit proof, permissible load >10 kΩ.

Limit Multiply

• Remote, relay input, 1.00-4.99 factor.

Trip Bypass

• Remote, relay input.

Environmental, General

• Module: IP 00, DIN 40050.
• Front Plate: IP 21, DIN 40050.
• Climate: DIN 40040 class KTF.
• Operating Temperature: 0° – 65°C (32° – 149°F).
• Storage Temperature: -30° – 85°C (-22° – 185°F).
• Relative Humidity: 5 – 95%, non-condensing.
• Vibration: IEC 68-2, part 6, 0.15 mm, 10 – 55 Hz, 19.6 mm/s2, 55 – 150 Hz.
• Shock: IEC 68-2, part 29, 98 m/s2 peak, 16 ms.
• EMC Resistance: EN50081-1 / EN50082-2.
• Power Consumption: Max. 6 W, 250 mA at 24 VDC.
• Configuration: Password protected.

A6312-8 Relay Module Dimensions

• PCB/EURO card format according to DIN 41494, 100 x 160mm (3.937 x 6.300in).
• Width: 40.3mm (1.59in) (8 TE).
• Height: 128.4mm (5.055in) (3 HE).
• Length: 160mm (6.300in).
• Net Weight: Approx. 320g (0.705lbs).
• Gross Weight: Approx. 450g (0.992lbs) (includes standard packing).
• Packing Volume: Approx. 2.5dm