Other Problem Generators 200kW Voltage Unstable

8 comments

Rate

hauguelpa Associate Join Date: Jan 2012 Posts: 34	Other Problem Generators 200kW Voltage Unstable 06/06/2012 1:21 AM
	hello, I have another kind of problem on the starboard diesel generator of my high speed ferry. diesel generator 200kW: -engine is caterpillar C9 -alternator is leroy somer LSA M 46.2L9 C6/4, 400V, 3P, 50Hz, 1500rpm, regul R448 AREP two problems: -sometimes (but not so ofen than on portside), engine is running, speed is OK but we have no voltage. -3 months ago voltage starts to be very unstable and finally increased a lot (400V to 475V), we have changed the AVR and every things seems to be ok. But now, we have the same problem every 100h running. Each time we change the AVR, voltage is stable during 100h and then again... All the broken AVR have the same problem: evidence of overheating of the two resistances close to P1. Leroy somer told us that these resistancesare for "parallel operation of diesel generators" but we NEVER run disel genrators in parallel. what we did: -changed the diodes , no change -took mesurement of the resistances of the windings, nothing strange We already saw 3 technicians for this problem but they have no idea... do you have any idea? do you know any test we can do to find the problem? thanks for helping pa
	Register to Reply
	Pathfinder Tags: generators

Interested in this topic? By joining CR4 you can "subscribe" to
this discussion and receive notification when new comments are added.

These comments received enough positive votes to make them "good answers".

harry potter Power-User Join Date: Nov 2008 Location: India Posts: 333 Good Answers: 6	#1 Re: other problem generators 200kW voltage unstable 06/06/2012 6:29 AM
	Dear, The problem seems to be with insulation of the excitor winding. Since, you have mentioned this is a problem occurring after fixed time of Hrs. operation,, seems to be related to thermal. That seems to be with the insulation quality of excitation winding. that is getting on the point of break down, but not totally failed. with this, resistance of AVR may be getting hot. Un stable voltage & some times zero voltage all tending to the same indication. Why don't you just Over haul the alternator winding - revarnishing the winding, drying, etc... Just check the hot spots on winding, if any .... __________________ Exploring the Science of Electricity
	Register to Reply Good Answer (Score 3)

Bibo92004 Associate Join Date: Jul 2011 Posts: 29 Good Answers: 2	#2 Re: Other Problem Generators 200kW Voltage Unstable 06/06/2012 7:48 AM
	I agree with harry potter.. I would advice you to check the insulation of your generator's field winding and inspect the rotor. A major overhauling could be your solution. I am afraid that what may caused your AVR to overheat is some current leakages in your excitation system.
	Register to Reply

arifkunnath Commentator Join Date: Oct 2011 Posts: 95	#3 Re: Other Problem Generators 200kW Voltage Unstable 06/06/2012 8:08 AM
	This type of problems happens when you run diesel generators for long hours continuously . That too at full load. Is this ferry operates 100hr continuously ?
	Register to Reply

SimpleMind Guru Join Date: Sep 2009 Posts: 1056 Good Answers: 88	#4 Re: Other Problem Generators 200kW Voltage Unstable 06/06/2012 8:18 AM
	I am convinced that the two problems you encounter on this gen are absolutely related, and the problem is most likely on connections or adjustments. Verify from scratch that ALL connections are according to manual especially the ST5 LAM (load acceptance) function or possible reversed connection on S1,S2 (if used for current sensing). With decent troubleshooting on the starting problem, it CAN be diagnosed, but I am sure you are not the only one that has to deal with a less competent technician (that also possibly sells AVR's.) S.M. __________________ Life is complex. It has a real part and an imaginary part.
	Register to Reply

hauguelpa Associate Join Date: Jan 2012 Posts: 34	#5 Re: Other Problem Generators 200kW Voltage Unstable 06/06/2012 4:35 PM
	sorry, it was not clear in my first message. It is not 100hours running continously. It is 100h but running 12 hours and stopped 12hours etc.... thanks a lot for your help it is very helpful pa
	Register to Reply

hauguelpa Associate Join Date: Jan 2012 Posts: 34	#6 Re: Other Problem Generators 200kW Voltage Unstable 06/07/2012 9:45 PM
	no more ideas?
	Register to Reply

PWSlack Guru Join Date: Jan 2007 Location: In the bothy, 7 chains down the line from Dodman's Lane level crossing, in the nation formerly known as Great Britain. Kettle's on. Posts: 32175 Good Answers: 839	#7 In reply to #6 Re: Other Problem Generators 200kW Voltage Unstable 06/11/2012 3:48 AM
	What was the outcome of the telephone call to the original equipment manufacturer's technical helpline? __________________ "Did you get my e-mail?" - "The biggest problem in communication is the illusion that it has taken place" - George Bernard Shaw, 1856
	Register to Reply

hauguelpa Associate Join Date: Jan 2012 Posts: 34	#8 Re: Other Problem Generators 200kW Voltage Unstable 08/03/2013 4:22 PM
	hi problem disappeared thanks pa
	Register to Reply

These comments received enough positive votes to make them "good answers".

Copy to Clipboard

	Got Something to Say?
	Ask a Question Start a Discussion

	Aerospace
	BioMech & BioMed
	Chemical & Material Science
	Civil Engineering
	Communications & Electronics
	Education and Engineering Careers
	Electrical Engineering
	General Discussion
	Instrumentation
	Manufacturing
	Mechanical Engineering
	New Technologies & Research
	Software & Programming
	Sustainable Engineering
	Transportation

	Site Directories
	Forum Directory Blog Directory User Group Directory RSS Feeds CR4 Rules of Conduct CR4 FAQ Site Glossary Who's Online (146 right now) Show Members