Troubleshooting

This week I have done schedule maintenance of a fire detection loop that includes manual call point, hooter etc. This loop also includes fire fighting system for two lube oil tank based on flame detection and deluge valve based high velocity water spray system. As advised by a senior engineer, we have used cable lugs for connection of manual call points and hooter/ sounder to minimize unexpected earth fault, short circuit faults. We have also determined which types of cables lugs is appropriate for this loop. ...

Practical lessons from troubleshooting a generator hydrogen purity analyzer using systematic fault isolation and OEM calibration procedures.

Today I investigated a CT fan motor current feedback issue in an Emerson Ovation DCS where the analog input showed BAD VALUE with frozen low current indication. Initial checks suggested either: AI channel failure Current transducer issue Open 4–20 mA loop Field ammeter indicated normal motor current, which confirmed the actual process was healthy. After tracing the signal path and comparing with a healthy loop, a loose cable termination inside the switchgear was identified. Replacing the cable lugs and tightening the terminals restored a stable 15 mA signal and normal DCS indication. ...

As per CCR information, I checked historical data and logics of gland steam supply system valves and found out that the valves are working as per control signal, however the fluctuation of pressure arises from somewhere else, the control valve operation is not the cause of the fluctuation, rather it operate in accordance of the pressure, hence it is the effect.