Replacing a generator -any ideas?

[stiknstring]

I have a 5 year old generator (4.56KVA) which despitre having only 134 running hours, has failed on the generator side (not the engine side). I am starting to have little faith in this unit and have asked the OEM to respond with an offer on the quoted £1200 repair cost. However, for such a major failure to occur within so little time, my confidence is low that this will last a more rigorous life when the boat relocated to the Med next year.

So, am seriously thinking of junking the whole unit and putting in a unit with a strong reputation for reliability.

Question is - what generators have the best reputations at this size? Your views will be read with much interest - thanks in advance.

I have intentionally not named the manufacturer of the unit giving me trouble until I get a rersponse from the head office on the repair cost - sorry!

 

[Portofino]

Well I,ll kick off
Small genys , usually do not get used enough and due to size/ wieght issue are normally 3000 rpm and have other design feature s like direct cooling .
I have a 9 y old 4.5 Kv fisher Panda
It's been fine but only 260 hrs .this year the water stopped coming out .= thermal guard shuts it down
A quick call to FP uk in Dorset , diagnosed a corroded " water connection block"
It's special alloy anode that takes the hit with the sea water corrosion , eventually furs up inside .
They sent one that day in the post to So F marina office . 3 days later I fitted it
Reasonable skills needed DIY. Hey Presto up and running
My engineer carries out annual oil change .
New impeller biannually .
It's in a sound box , fitted by SS in the factory has the super silent exhaust dispute 3000 rpm it's pretty quite.
So this is my experience of a small Geny
Service book has pages to stamp up to 9000 hrs
Like all tech things I think follow the maintainance instructions

 

[rotrax]

£1200.00 sounds a lot for the generator bit, which after all is old tech stuff-a rotor and stator and a regulator. I cant imagine all of these will be defective-if they are you should get that unique electrical burning smell if you take a good sniff in the genny box. Plenty of specialists can diagnose and subsequently rewind rotors and stators economicaly. I hope you get a result with the supplier-it sounds to me like they intend to change all of the generator bits if the price quoted is correct. Good Luck.

 

[dratsea]

Swapped Onan for Pagura 5000,

Much better, alternator is SS covered and cooling water goes there first, through block and out in exhaust, Farryman single cylinder engine, basic and reliable. Fitted in Guernsey for about 5K.

 

[William_H]

Generator

I can't help feeling you are condemning the generator too soon. If it is an electrical fault then just a loose or broken wire can cause total failure. The quoted price may involve removing the gen which in itself may be a lot of work. If you demand a quote then they will of course quote for worst case scenario. Perhaps safer to pay by the hour but then if he is a dumb technician you will pay too much. A sad a good electrician might fix it really easily.
Unfortunately single cylinder engines vibrate a lot and electrics don't handle vibration well. I once got a petrol gen to fix. I was amazed the way solid piece of bronze electrical strap had fatigued from vibration.
As said with your gen there is not much involved with the electrics. Quite likely a replacement control box would fix it. (if it has a separate box).
Essentially you have an alternator with a rotating field coil. This is fed by DC through brushes. The brushes can give trouble. Check them for pressure on the slip rings. Any problem here is usually identified by burnt slip rings.
The AC is taken off the outer coils which should be quite robust. The AC output is sampled and rectified to feed the field coils the current being appropriate and adjusted automatically to give your correct output AC volts for the load. Anyway probably doesn't help you but good luck olewill

 

[david_bagshaw]

I have a 5 year old generator (4.56KVA) which despitre having only 134 running hours, has failed on the generator side (not the engine side). I am starting to have little faith in this unit and have asked the OEM to respond with an offer on the quoted £1200 repair cost. However, for such a major failure to occur within so little time, my confidence is low that this will last a more rigorous life when the boat relocated to the Med next year.

So, am seriously thinking of junking the whole unit and putting in a unit with a strong reputation for reliability.

Question is - what generators have the best reputations at this size? Your views will be read with much interest - thanks in advance.

I have intentionally not named the manufacturer of the unit giving me trouble until I get a rersponse from the head office on the repair cost - sorry!

Smaller sets often fail when the rather large and expensive capacitors let go.

If size permits suggest a 1500 rpm unit, personally we have an onan 7.5kva set, and am very happy with it over 12 years old and 3000 hrs.

we had a zeise unit powered by farryman 3000 rpm set which had been abused before our ownership, however was the most unreliable piece of **** as it would rarely manage 50 hours between stoppages. All stupid vibration fractures and the tiny belt driving the coolant pump. Made the pump direct drive via the hand start drive to help its reliability.

 

[KellysEye]

When we were in theCaribbean our generator failed and I asked a number of repair shops which generator they had to least repair. The yellow jersey went to Northern Lights followed closely by Westerbeke, Fisher Panda came bottom. We went with Westerbeke because they have a better worlwide network if you need repairs, which we haven't had to do, after two hours a day of use for six years.

 

[Ariadne]

Well don't fit a Deficient Panda, have a good around the web and you'll be amazed at how many of them fail. We know at least 4 people who have them and none of them are happy and would happily swap them.

If Gruntle is about on here these days, he fitted 4Kw diesel site generator on his boat, a bit noisy but very efficient and incredibly cheap even with marinising (sp?)it.

 

[LionsDen]

We have an Onan 4kw generator on our boat - really quiet - Princess also install a exhaust water muffler as a factory fit which helps keeps the noise down - Great unit will last for years if used frequently as per the manufacturers guide lines.

I feel that the problem you may have with your generator is also possibly due to lack of use.
A few previous answers to this thread have stated 2 hours a day use for 6 years = over 4000 engine hours and a unit has been used 3000 hours over 12 years which equates to 1 hour a day. Trust this assists.

 

[Portofino]

Google " problems with ------------ marine generator "
Insert---------- any brand Onan , masse , westerbeke , fisher panda , Kohler ect ,
Throws up all sorts of tale s of woe , seemingly in equal measures .
Tiny small genys , by their very nature are not designed to sit in the middle of an engine room the size of the Albert Hall. With all the componants neatly arranged There in lies he problem = compact design compromises .like direct water cooling ( no heat exchanger bulk )' this means corrosion has to be managed , anodes replaced
Pipework seems only placed in silly places waiting to leak- spill out over sensitive electrical devices , because they have routed it as such to minimise external dimensions ,exhausts manifolds water cooled ( chance of back flow if incorrectly installed ) = knackered engine , or corrosion if left for weeks unused .
Sound boxes and installation in the bottom of a locker in tight spaces = neglected basic checks , because the owner is not as supple as Harry Houdini .
Now I winterise my FP , so it sits full of antifreeze for 6 months rarther than sea water. Also regularly check , nip up any hose conections and all nuts ,( single cylinder ferryman diesel ) Basically follow the " book" cut no corners
I feel there is no such thing as a fit and forget small compact Geny .
As mentioned lack of use kills them off.
Large genys let's say a 17kv any make in a 70 ft fly bridge , this thing will be on more than off to power the a/c , freezer , fridge water maker , ice maker , drinks chiller Blackpool illuminations at night and the mini odeon cinema , that's in each cabin ,
It will be over engineered all the pipe work laid out sensibly, a smooth multicylinder engine etc , Very easy to do the daily checks - in the Albert Hall esq engine room
Mean while the poor little " junior" 4 Kv in a 37 ft boat is only turned on for 1- 2 hour a day if it's lucky , , most likely left neglected for weeks ,. This because this boat has not many of the appiances , as the 70 ft er and when on, trying its damdist to vibrate it way out of the sound box loosening all the fittings , coughing and splitting out the results of direct seawater cooling .
Meanwhile senior - the17 Kv modal is luxiating in a a cool solution of ethylene glyco ( heat exchanger) , pumped around by a brass pump that almost weighs the same as the whole 4 Kv junior
Juniors maintenance manual is 3 x a thick as seniors , cos there is more to go wrong .
Few years later junior dies of neglect having done v few hours

 

[Talbot]

When I took over my boat, the generator was shown running (and FP). When I came to run it 6 months later, the coolng water flow had ceased and the machine shut down completely. I have now got it running again and discovered the following>

1. The FP anode that diverts the cooling flow through the inverter side (large block of aluminium) is available in two versions. One has an additional outlet that allows a small flow direct to the exhaust. This version is more expensive and is the first place to bung up anyway. Following advice I went for the cheaper version and got rid of the third outlet.

2. The generator has a thermostat, this had failed closed. The expert advice was to remove it and not replace. This increases the cooling flow and helps to avoid blockages.

3. My blockage was in the head and in the main cylinder block. They are very easy to take off and work on - but test that all the blockage has been removed before re-assembly as the head gasket is expensive if you need to pull it apart again.

4. Buy a fresh water cooled generator next time! or set yours up so that you can flush it through with anti-freeze and fresh water after use.

5. Run it at least once per month but preferably more often.


My FP has done over 2000 hours, and with the proper care and attention should do at least that much again. I suspect that most of those on the market have been ignored and then failed when run up. I proved that proper maintenance can restore such a machine at a lot less cost than replacement, although I was tempted to replace with a fresh water cooled unit.

 

[boatmike]

Everyone is right!

But you need to put it all in context. I have been in charge of many refits of larger yachts and in my experience larger gennies that are run continuously rarely give problems. In the small yacht, just like small diesel auxilliaries, the long periods of idleness, short running periods and lack of maintenance, especially over the winter period, kills them through corrosion, salt build up and general malaise that will affect anything mechanical that is not used regularly. There is no doubt that larger, more expensive 1500RPM sets will last better and be quieter than most little farryman based 3000RPM sets, but there is no reason to condemn them generally. Just recognise that they need to work like any diesel and don't run it for 30 minutes at a time just to boil a kettle.... Also never buy a cheap seawater version. Indirect cooling is far better, but even then flush through the circuit with fresh water if you are not going to use them for any long period. Also recognise that the little Fischer Panda jobbies are very light compared to an Onan or WHY and are very cost effective compared with the larger sets generally. In my opinion it's usually the little farryman diesel that dies first, not the gennie, and that is (again like auxilliaries) due to misuse not wear. In fact with proper maintenance they very rarely wear out.
I agree also with the advice regarding the original post. Get a competent engineer to look at it and tell you what has failed. It may only be a minor electrical component.

 

[Trundlebug]

I'm not a fan of generators. Noisy, unreliable, expensive, antisocial, maintenance intensive and IMHO unnecessary for most boats.

For much less money and similar space you could fit several extra batteries, and charge them via solar panels especially in the Med.
Your power source would then be silent and almost maintenance free.

Other than for electric cooking and aircon, everything else can be very satisfactorily powered from 12v. Hair dryers, computers, TV, fridge, heating, the lot. Without any major compromises.

As we have gas cooking and no aircon, no need for a generator.

It may not work for everyone and depends on your circumstances but all I'm saying is, It's worth considering all the options not just replacing like for like.

 

[KellysEye]

>A few previous answers to this thread have stated 2 hours a day use for 6 years = over 4000 engine hours and a unit has been used 3000 hours over 12 years which equates to 1 hour a day.

Modern 1,500 rpm generators are lifed for eight years even with heavy use, as are most marine diesel engines. 3,000 rpm generators are lifed for 400 to 600 hours although some will last 1,000 plus but usually with much maintenance. Our 3,000 rpm generator, fitted by the previous owner, commited suicide after 550 hours and we replaced it with a 1,500 rpm unit.

 

[npf1]

Smaller sets often fail when the rather large and expensive capacitors let go.
QUOTE]

BTW - they are only expensive if you buy them from the generator manufacturer. Exactly the same capacitors are available from industrial electrical motor specialists. For example, a few years back I was quoted around £70 each plus VAT from FP. My genset has nine of them and a motor specialist in Brum supplied them all for under £100.

IMHO, if you have a gen that relies on capacitors, it's worth reading the manual to a) recognise the signs when one has gone, as the symptons can have you chasing a mechanical issue; and b) know how test and change them. It is is very simple job.

 

[boatmike]

>A few previous answers to this thread have stated 2 hours a day use for 6 years = over 4000 engine hours and a unit has been used 3000 hours over 12 years which equates to 1 hour a day.

Modern 1,500 rpm generators are lifed for eight years even with heavy use, as are most marine diesel engines. 3,000 rpm generators are lifed for 400 to 600 hours although some will last 1,000 plus but usually with much maintenance. Our 3,000 rpm generator, fitted by the previous owner, commited suicide after 550 hours and we replaced it with a 1,500 rpm unit.

Please let us all know the source of your statistics. I know of no published data that supports your statement. I would also add that I have personally replaced several generators on superyachts when refit time came around. The oldest was a Westerbeke that had done over 17000 hours and was still running perfectly and only replaced at the owners request.

 

[timchapman]

>A few previous answers to this thread have stated 2 hours a day use for 6 years = over 4000 engine hours and a unit has been used 3000 hours over 12 years which equates to 1 hour a day.

Modern 1,500 rpm generators are lifed for eight years even with heavy use, as are most marine diesel engines. 3,000 rpm generators are lifed for 400 to 600 hours although some will last 1,000 plus but usually with much maintenance. Our 3,000 rpm generator, fitted by the previous owner, commited suicide after 550 hours and we replaced it with a 1,500 rpm unit.

' ...3,000 rpm generators are lifed for 400 to 600 hours....'

Interested to know where you get this from, or did you make it up?

 

[david_bagshaw]

If size permits suggest a 1500 rpm unit, personally we have an onan 7.5kva set, and am very happy with it over 12 years old and 3000 hrs.
.

If I can quote my self

the 3000 hours were run during periods in commission, usually with the engine running for between 1 hour and 6 hours, some times 10 hours per day. So many brew ups, many cook ups, as we have an all electric galley

certainly not one hour per day!