Earth fault trouble shooting on WECS8000 Control Systems [Wartsila Engine]

Earth fault trouble shooting on WECS8000 control systems

All circuit diagrams shown on this document are for example, installation wise circuit diagrams are needed for execution of work.

1. Visual inspection

This inspection can be done even the engine is running.

Inspect inside of all electrical cabinets and CIB modules tightening of the wires to connection terminals to avoid loose contacts.
Check all cables leading through the cable glands if there are visible damages which can affect earth fault.
If you find “white powder” inside of the electrical cabinets, it’s a mark from wires scuffing/abrasion due to vibration and is potential source for the earth faults.
Tighten all free wires with cable ties inside of the electrical cabinets to avoid vibration damages.

2. Earth fault tracing

The engine need to be stopped and earth fault alarm should be ON.

• If the earth fault alarm don’t persist when the engine is stopped, the fault tracing is not possible.

If the earth fault alarm doesn’t have automatic reset, it’s needed manually reset after every step of the fault tracing!

Disconnect 24 VDC and 110 VDC primary and backup powers with the power module main switches to separate engine from other installation systems.

• If the alarm still persists, start to find it from outside of the engine.

Connect back 24 VDC and 110 VDC powers and the earth fault alarm should come back.

Disconnect from the power module 24 VDC and 110 VDC power supply to A- and B-bank control modules.

• If the alarm still persists, start to find it from inside of the A1, A2, Communication module and Power module.
  o Disconnect from the power module power source to other systems one by one to find the source of the fault. Remember disconnect at the same time the +24 VDC and from the same circuit 0 VDC!
• If the alarm disappears, connect back the A- and B-bank power sources. The alarm should come back.

Disconnect the A-bank power source

• If the alarm disappears, connect back the A- bank power source. The alarm should come back.
  o Disconnect one by one the control modules 50-pin connectors (MCM have three pieces and CCM have two pieces) until you find the module which is the earth fault source.
  o Connect back the fault source module 50-pin connectors. Start to disconnect sensors-; valve-; signal wires from the CIB connectors until you find the faulty one.

• If the alarm doesn’t disappear, connect back the A-bank power source.

Disconnect the B-bank power source

• If the alarm disappears, connect back the B- bank power source. The alarm should come back.
  o Disconnect one by one the control modules 50-pin connectors (MCM have three pieces and CCM have two pieces) until you find the module which is the earth fault source.
  o Connect back the fault source module 50-pin connectors. Start to disconnect sensors-; valve-; signal wires from the CIB connectors until you find the faulty one.

Regards,

@khanza.aulia