Engine Mounted WECS Controllers on Wartsila Diesel Engines

[anythingwithawire]

Hi

I do a bit of troubleshooting work in the marine industry and seem to be coming up against one particular problem over and over - electronic diesel engine controllers by Wartsila (WECS series) on medium/large (say 500kW to 2MW) reciprocating diesel engines for generators.

There are edge coneector cards, small potentiometers and relays in these things and apart from premature failure, there seems to be problems with resonance on the relay armatures causing false shutdowns under certain semi-repeatable conditions.

You can see the whole unit vibrating at different frequencies at different times and the are all sort of mechanical beat frequencies and harmonics going on. I have seen many, many part or complete failures in equipment less than 3-5 years old, the current one only 9 months and 2 out of 5 are tripping intermittantly with no indication.

Wartsila have advised to remove some connectors/plugs for one of the units, but now the 1.5MW diesel is unprotected for some functions. (but it is running without tripping, fantastic - sarcasm always works for me). Meanwhile they are sending someone out from the factory in '2 or 3 weeks'. Cost of blackout on this deal is up to maybe 70 million if not recovered quickly enough due to equipment damage and contractual issues. (I am trying to be a little general here for commercial reasons).

The mounting of these systems on the engine just seems flat out dumb and I can't see why you would do such a stupid thing when the engine room environment is already very harsh, and then they pick the worst possible place to put them.

Has anyone got any comments. I can post a photo later, but I am on a boat right now with limited bandwidth.

Thanks

AnythingWithAWire.

 

[ScottyUK]

Without being familiar with the specific equipment,I have to agree that intentionally mounting anything on a recip engine which could be mounted somewhere else seems like a bad idea. That said, Wartsila have been in the engine game for a little while now and hopefully would have thought about mounting electronics on the engine.


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If we learn from our mistakes I'm getting a great education!

 

[anythingwithawire]

Hi Scotty

They have been in the game for a good while, but as reciprocating rather than electronics experts. Also,I think this issue is due to transmission of vibrations through the structure, and beats with other equipment, whereas a lot of their stuff is often mounted on land on a concrete plinth or a sole engine in a rail application.

I have seen too many problems to do anything other than recommend strongly that all electronics be mounted off engine - they make a standard cable extension kit to allow this.

I used to design consumer electronics with runs of 100/1000 and once had a board with a 7805 voltage regulator and heat sink where every single one of over 100 fatigued off in road transport (Australia mind you) due to cantilever resonance.

Thanks for the feedback,

AnythingWithAWire

 

[itsmoked]

If you have any concern at all I'd certainly move the stuff off the vibrating structure. Edge connector boards are rapidly compromised by vibration. You could also leave them on the system but re-mount the controls onto a damping system.

Keith Cress
kcress -

http://www.flaminsystems.com