3A99165G51 Servo Amplifier Module | Emerson Ovation DEH Turbine Control_Ningde Androld Automation Equipment Co.,Ltd.

June 05, 2026

3A99165G51 Servo Amplifier Module | Emerson Ovation DEH Turbine Control

PN:3A99165G51 | Manufacturer: Emerson (Former Westinghouse Ovation DCS) G51 is a site-customized upgraded variant of the 3A99165 full-series servo driver card, specially optimized for 600MW/1000MW ultra-supercritical thermal power plant DEH hydraulic control system, compatible interchangeably with G04/G05/G50/G52 series servo boards, paired with master control card 3A99164G50 for turbine valve closed-loop regulation.

Description

1. Product Overview

3A99165G51 adopts standard single-width Eurocard structure for Ovation rack mounting, direct plug-and-play replacement without cabinet wiring modification.

Core function: Receive ±10VDC differential analog/PWM valve position command from upper main controller; convert command signal into precision constant current to drive EH servo actuator coil; collect low-amplitude AC LVDT feedback signal to realize closed-loop positioning of turbine main stop valve, governing valve and bypass valve.

Key upgrade vs G50: Optimized wide-range input signal conditioning circuit, improved anti-drift operational amplifier chip, adjusted output current curve for medium-impedance imported servo valves widely used in domestic large-capacity generating units, enhanced anti-vibration PCB layout to reduce field drift failure caused by cabinet vibration.

2. Electrical Specifications

Backplane power supply: +5VDC, ±12VDC, powered by rack 3A99132 series PCPS power module
Command input: ±10VDC differential analog input / PWM modulation control signal, with built-in 20mA signal adaption circuit for field conversion wiring
Adjustable constant output drive current: 0~±48mA, between G05(45mA) and G50(50mA), suitable for most conventional and imported EH servo coils
Feedback channel: Multi-group low-level AC input terminals dedicated for LVDT displacement transducer connection
Onboard protection: Independent channel fuse, multi-stage TVS surge suppression array, precision gain calibration potentiometer, overcurrent, overheat and short-circuit latch protection, full-board multi-stage RC EMI filter network

3. Environmental & Mechanical Parameters

Operating ambient temperature inside cabinet: -14℃ ~ +72℃; storage temperature: -40℃ ~ +90℃
Humidity: 5%~95%RH non-condensing; full PCB with industrial three-proof conformal coating (moisture, mildew, salt fog resistant)
EMC compliance: IEC61000-6-2 heavy industrial anti-interference standard, resistant to interference from cabinet contactors, high-power inverters and power frequency harmonics
Dimension: Unified standard Ovation single-slot card outline, fully mechanically compatible with all 3A99165 series servo amplifier boards

4. Front Panel Indication & Maintenance Function

Four independent LED indicators on front panel: Power Normal, Input Command Abnormality, Output Overload, LVDT Feedback Fault; reserved onboard test pins for multimeter debugging and closed-loop gain calibration during unit overhaul.

Supports hot-swap replacement under live rack power; critical governing loops usually adopt redundant dual 3A99165G51 configuration to guarantee uninterrupted turbine valve control during single-card maintenance.

5. Market Supply & Common Fault Diagnosis

Original OEM new production discontinued; available stock includes original surplus unused stock and fully bench-tested refurbished modules, standard 12-month industry warranty for refurbished goods.

No driving output: Blown built-in channel fuse or damaged post-stage power amplifier component
Continuous valve hunting/oscillation: Aging filter capacitors or deviated gain potentiometer setting value
Slow valve position drifting: Performance degradation of LVDT pre-amplifier circuit or oxidized PCB gold finger contact

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