Steering gear fails to operate in FU (Follow Up mode). Rudder does not stop in ordered angle position. It travels up to hard Port/Stbd (35 deg) and than stuck there.

NFU (Non Follow Up) mode works normal.

Any ideas?

Steering gear Maker: Yokogawa; Model: PT 120

Auto pilot Maker: Yokogawa; Model PT500D-K-N2

04 May '17, 22:48

May 4, 2017, 10:48 p.m.
KnowledgeBase's gravatar image


Inspect u-Transmitter (rudder angle feed back transmitter) for Autopilot which mounted on the Steering Gear. Inside you will find 2 limit switches which get activated at Max Port / Stbd rudder angle. Check their operation. If one or both of them failed/stuck the PCU supplied with wrong Max Angle limit signal. Wrong/fake input data could make it's software to fail.

permanent link

04 May '17, 22:58

May 4, 2017, 10:58 p.m.
SeamenExchangeExpert's gravatar image

add your answer

MarineProHelp 2018 - 2021