3A99165G02 DEH Turbine Servo Control Board | Emerson Westinghouse Ovation DCS (English Version)_Ningde Androld Automation Equipment Co.,Ltd.

June 05, 2026

3A99165G02 DEH Turbine Servo Control Board | Emerson Westinghouse Ovation DCS (English Version)

PN:3A99165G02, Cross OEM PN:7379A31G02, DEH electro-hydraulic servo control dedicated PCB for Ovation turbine governing system, matched with 3A99164 series speed control card for fossil & nuclear power TG unit DEH cabinet

Description

1. Product Overview

3A99165G02 is a single-width Eurocard plug-in servo amplifier board under legacy Westinghouse Ovation DEH (Digital Electro-Hydraulic) turbine control subsystem, paired with 3A99164G50 speed controller to constitute full closed-loop steam turbine valve regulation circuit. It receives PWM command signal from upper speed control board, amplifies analog drive output to directly control EH hydraulic servo valve, implements turbine main steam valve, governor valve opening adjustment for unit speed & load closed-loop control. Fully pin-compatible drop-in replacement for predecessor G01 revision, widely equipped in thermal power plant turbine EH control cabinet and nuclear unit TG governing rack.

2. Core Electrical Specifications

Rack power supply: +5VDC, ±12VDC fed by PCPS power module (3A99132 series) via crate backplane bus
Control input: ±0~10V analog command signal / PWM modulated signal from 3A99164 series main control card
Servo drive output: ±0~40mA proportional current output for EH electro-hydraulic servo coil drive
Onboard built-in: input surge protection, output short-circuit fuse, adjustable gain potentiometer for servo loop calibration; RC filter network to suppress cabinet EMI noise
Feedback channel access: onboard terminal for LVDT valve position feedback signal acquisition to form full closed-loop position regulation

3. Environmental & Physical Parameters

Operating temperature: -10℃ ~ +60℃ inside sealed DCS cabinet; storage: -40℃ ~ +85℃
Humidity: 5%~95%RH non-condensing, PCB with anti-corrosion conformal coating, complies IEC61000 industrial EMC anti-interference standard
Dimension: Standard Ovation single slot size 327×138×22mm; net weight ≈1.36kg (3.0 LBS)

4. Installation & Operation Feature

Standard hot-plug capable for Ovation DEH dedicated rack slot; critical turbine cabinets adopt dual redundant 3A99165G02 redundant configuration for uninterrupted servo control
Front panel equipped multi LED indicators: board power OK, input fault, servo overload, LVDT feedback abnormal; reserved test points for field multimeter calibration and loop tuning without cabinet power cut
Onboard adjustable trim resistors to modify servo loop gain for matching different model EH servo valves on-site

5. Spare Part Supply & Warranty

Original Emerson/Westinghouse OEM production discontinued; available stock includes unused surplus original and fully bench-tested refurbished modules, all undergo full servo signal simulation test before delivery. Global courier shipping via DHL/UPS/Fedex, standard 12-month test warranty after shipment.

6. Common Field Troubleshooting

Turbine valve hunting/oscillation: damaged onboard filter capacitor or drift of servo gain potentiometer
No servo valve action: blown onboard channel fuse or broken output power driver circuit
Valve position drift: aging LVDT signal input circuit or PCB gold finger oxidation causing poor contact
Full board dead status: abnormal backplane ±12V supply or internal primary circuit open fault

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