Which genny?

[boatmike]

Thanks to a previous thread on aircon I am now convinced that to livaboard in the med I need a genny. In fact I now think it would be daft to avoid having one. Having converted recently from open sea sailboat cruising where the whole philosophy was keep it 12v and simple as possible, I am now talking about pottering and just living aboard which is a totally different concept. You guys are slowly converting me!
So the next question is how big? Although there are nice little 3KVA sets out there I think at least 5KVA would be sensible with aircon, TV, electric kettle, toaster, microwave etc.
I do have a big battery bank and inverter so won't run it all the time but when not on shore power in marinas, need to run all AC stuff and keep batteries full so think 5KVA probably big enough? What do you guys use? Also I have looked at Fischer Panda and Pagero but are there others? Any thoughts more than welcome..... Ta!

 

[aquapower]

I would have an Onan or Westerbeke, and at least 5 kva if you running aircon

 

[yesod]

northern lights or onan - slow reving ones. pagero is interesting due to the stainless construction and ability to hand start should everything be flat.

 

[jfm]

I you want top quality and good service/parts back up in the med then get Cummins Onan or Kohler, and nothing else. These are the best, together with Northern Lights but NL have a manky old fashioned control panel. 5Kw is prob ok, esp if you spec VFD on the airco to eliminate the motor start-up spike

If you get a make like HFL or other types that are not popular in the Med you will not have great back up. Fischer Panda has some med back up but nothing like Onan/Kohler/NL

Gensets at this size come in 2 types. First there are 1500rpm fixed speed types, and the electronics just squirt in more fuel (hence more torqque) as you increase the 230v load. And second there are variable speed types, where the engine revs up as you increase the load, and the output is rectified to DC then inverted back to DC, urgh, in order the get the correct 50Hz

The former, ie the fixed speed 1500 rpm jobs, are the best and purists prefer them. Cummins Onan, NL and Kohler make this type. The variable speed type will work but feel a bit mickey mouse because you hear the engine rev to 3000rpm as you turn the kettle on...

 

[admillington]

I would go for the Onan 7 kw to cope with the Aircon startup loads. Excellent 3 cylinder Kubota engine.

 

[david_bagshaw]

I would go for the Onan 7 kw to cope with the Aircon startup loads. Excellent 3 cylinder Kubota engine.

another vote for the above.

Seeing you are starting from no existing equipment,

get hold of victrons booklet on generators & inverters, as combined you can get capability of high total loads, along with good generator efficiencies, by providing low load use from the inverter.

 

[henryf]

Yet another vote for Onan. So pleased with ours. Nice and quiet.

Keep it serviced properly (including impeller) and it'll give good service.

Henry

 

[Deleted User YDKXO]

Vote for Kohler fro me. Had them on my last 3 boats and never had a moment's problem with them except one time but that was inflicted by an idiot service technician. Only thing I would say is that avoid generators powered by high revving (3000rpm) single cylinder engines which are far noisier and more vibey than the low revving (1500rpm) 3 and 4 cylinder engines fitted to better gennies

 

[DougH]

Kohler or Onan (no experience of Cummings), good servicing and back up agents all over the Med.

7 kva may be more than you need but your needs could easily develop to require more power.

No need to go higher as you quickly learn to manage your power consumption to what the set is capable of producing on a continuous basis.

Remember a 7 kva set will only produce 7 kva for a short period not continuously.

Another good reason to choose a good set is that the generator will probably do more hours than your engines, especially if you are intending to be a live aboard.

You will love the Med Life.

PS Make sure you have one with underwater exhaust and if possible ok to run when underway as it can be very hot in August.

 

[jfm]

Kohler or Onan (no experience of Cummings),

Cummins and Onan are the same thing Doug. The brand is "Cummins Onan"

Remember a 7 kva set will only produce 7 kva for a short period not continuously.

I dont think that's correct and there is no engineering reason why it should be so. The ratings are generally continuous. Separately, when installed in a hot engine the output can be ~10% off the rated output because the diesel engine just cant develop the power when inhaling 45degree air

 

[Watson47]

boatmike .... After conducting a good deal of research, I was swayed by the DC generation argument & opted for a Fischer Panda AGT6000 (6kw), directly connected to my battery banks, together with a Victron Multiplus 23/3000/70 Inverter to provide the 230V supply. It is a very efficient system.

A brief summary by Fischer Panda on the methodology ...

"As an alternative to AC marine generators, Fischer Panda’s AGT marine generators provide the capability of a directly driven highly efficient DC charging solution onboard. Instead of supplying AC power directly
to the consumers, the AGT 6000 generator charges an on-board battery bank and the consumers are supplied power indirectly from the battery bank through inverters onboard. Where less AC power or high inductive motors
are not required onboard, the AGT 6000 offers a great solution to charge the batteries efficiently and quickly. Using less fuel, less noise, less maintenance and giving you ease of mind. The AGT 6000 is designed to run on auto-mode and monitor your battery bank, keeping the batteries correctly charged and ready to go. The AGT generators, depending upon the performance, voltage and amperage, can weigh up to 50% less than a conventional generator
and are up to 30% smaller in size."

I found Fischer Panda in Dorset top people to deal with. MD Barry Fower spent a LOT of time on my enquiry .. ! Excellent service.

http://www.fischerpanda.co.uk/marine_dc_generators.html

A Generator Test Report by Victron may also be of use to you in establishing the best generator for your needs;

http://www.victronenergy.com/generatortest/

PM if I can be of any further assistance.

 

[MapisM]

Yet another vote for Onan. So pleased with ours. Nice and quiet.

+3

 

[jimmy_the_builder]

Yet another vote for Onan.

Er, I think that makes me +4, I've got an Onan 4kw which I bought from Ace of this parish; very nice indeed. I also had the same model on my P42 previously. Dometic advised me that the 4kw Onan would be able to drive the 16000btu aircon. (They were at pains to point out that not all 4kw generators from all manufacturers would necessarily be up to the job.)

Cheers
Jimmy

 

[DougH]

Cummins and Onan are the same thing Doug. The brand is "Cummins Onan"

I dont think that's correct and there is no engineering reason why it should be so. The ratings are generally continuous. Separately, when installed in a hot engine the output can be ~10% off the rated output because the diesel engine just cant develop the power when inhaling 45degree air

Strewth John I did not even know how to spell Cummins properly, certainly did not know they were now one entity.

You are of course correct in your reasons for the reduction in rating output, it is just that I did not go into the finite details as the OP was only looking for general information.

 

[jfm]

boatmike .... After conducting a good deal of research, I was swayed by the DC generation argument & opted for a Fischer Panda AGT6000 (6kw), directly connected to my battery banks, together with a Victron Multiplus 23/3000/70 Inverter to provide the 230V supply. It is a very efficient system.

A brief summary by Fischer Panda on the methodology ...

"As an alternative to AC marine generators, Fischer Panda’s AGT marine generators provide the capability of a directly driven highly efficient DC charging solution onboard. Instead of supplying AC power directly
to the consumers, the AGT 6000 generator charges an on-board battery bank and the consumers are supplied power indirectly from the battery bank through inverters onboard. Where less AC power or high inductive motors
are not required onboard, the AGT 6000 offers a great solution to charge the batteries efficiently and quickly. Using less fuel, less noise, less maintenance and giving you ease of mind. The AGT 6000 is designed to run on auto-mode and monitor your battery bank, keeping the batteries correctly charged and ready to go. The AGT generators, depending upon the performance, voltage and amperage, can weigh up to 50% less than a conventional generator
and are up to 30% smaller in size."

I found Fischer Panda in Dorset top people to deal with. MD Barry Fower spent a LOT of time on my enquiry .. ! Excellent service.

http://www.fischerpanda.co.uk/marine_dc_generators.html

A Generator Test Report by Victron may also be of use to you in establishing the best generator for your needs;

http://www.victronenergy.com/generatortest/

PM if I can be of any further assistance.

Hmmm. That sounds like FP sales talk. FP have a position in the market with high revving variable speed diesel engine gensets which is an inferior technology and you will never find any seriously-specced yacht, nor indeed any power station with such gear. Electricity generated by a spinning prime mover is intrinsically AC. Fischer Panda, because of their chosen technolgy, have to rectify the AC that their machines produce to DC because they make variable rpm gensets. That is inferior engineering. The rest is FP sales talk to make a good story our of basically inferior engineering. Sure their sets can be lighter becuase they rev the balls off the engines (3500rpm etc) to get the power. Proper 1500rpm gensets have physically big diesels becuase their power is limited by the 1500rpm speed, but that's just what you want for a quiet long life installation. You wont find any super yachts with Fischer Panda technology on board

 

[MapisM]

J, if I understand what Watson47 said, he wasn't talking of generating 240V AC by mean of a high revving diesel engine instead of an electronically controlled 1500rpm one.
He's talking of having instead a DC low voltage generator (either 12V or 24V, not sure about what he has), meant only to recharge the batteries, which in turn provide the 240V AC needed for the onboard equipment via inverters.
I'm not sure if that affects your technical objections on spinning prime movers being inherently AC - maybe not so much - but actually there are some advantages in such solution, though so far I've only heard of it as a backup, where a plain vanilla AC genset is already installed.
Also because I don't think it would be such a great idea to run some equipment as A/C, oven and cooktop through the inverters, anyway...

 

[Latestarter1]

Strewth John I did not even know how to spell Cummins properly, certainly did not know they were now one entity.

You are of course correct in your reasons for the reduction in rating output, it is just that I did not go into the finite details as the OP was only looking for general information.

Cummins has been involved since 1986. Joint holding with good old Hawker Siddley until they ran into financial trouble, and Cummins purchased Onan outright in 1992.

All tied up with Newage, Worlds #1 alternator manufacturer. Newage was hugely innovative British company with a number of technical firsts. However typical of Britain and technology became a financial pass the parcel in the 1960's and wound into the Charterhouse Group even linked with British Leyland building marine engines at one point. When everything started to fall apart Onan purchased chunk of Newage to secure what they perceived as the best alternator technology.

Cummins created a very large group incorporating Markon, Newage in the UK and later AVG in Germany and was a little coy about fronting the Cummins name as they are major suppliers of alternators to the likes of CAT.

Cummins also purchased Petbow in Ramsgate, old established UK assembler of gensets and noted for their control gear technology. Renamed CPG. Became Cummins Power Generation when Cummins stopped being so coy about group company identities, Fleetguard, Holset, etc.

Onan benifits from being a member of just about the largest generator technology group in the World. In the US recreational market Onan and Kohler vie for #1 spot with Northern Lights and Westerbeke not far behind, they are all darn good sets.

Fischer Panda enjoy almost joke status in the US marine market and certainly have nothing to offer over the big four.

 

[jfm]

J, if I understand what Watson47 said, he wasn't talking of generating 240V AC by mean of a high revving diesel engine instead of an electronically controlled 1500rpm one.
He's talking of having instead a DC low voltage generator (either 12V or 24V, not sure about what he has), meant only to recharge the batteries, which in turn provide the 240V AC needed for the onboard equipment via inverters.
I'm not sure if that affects your technical objections on spinning prime movers being inherently AC - maybe not so much - but actually there are some advantages in such solution, though so far I've only heard of it as a backup, where a plain vanilla AC genset is already installed.
Also because I don't think it would be such a great idea to run some equipment as A/C, oven and cooktop through the inverters, anyway...

I fully understnad that. Fine as back up maybe, though you might as well just have two proper generators, but I don't see any "some advnatages" that you mention. Am I missing something?

It's a classic Fischer Panda solution where you generate AC at 12 or 24v with a variable speed diesel engine, then you rectify that to DC, then you invert it back to 230v AC to run your 230v loads. Urgh. It gets max power by thrashing the engine to 3500rpm and it revs up when you put the kettle on, and anyway is no good except for light loads. Latestarter comments above . Yep I know I'm being harsh on this product line but for someone contemplating a fresh installation as OP boat milke is, it is appropriate to tell the side of the story that you wont get from a FP salesman

 

[boatmike]

Just talked to Fischer Panda. Their DC sets are more expensive anyway so I think I will stick with AC. Incidentally their sales guy did not try to push DC and agreed that in my case a small AC set was the sensible choice. Having worked on superyachts most of my life I know and respect Onan and would only go to Fischer Panda if they were a good deal cheaper. They are obviously lighter and smaller and I won't rule them out but favour sticking to the devil I know and also agree that 1500RPM sets are preferable if I can afford one and can shoe horn it in somewhere. So thanks guys for confirming my thoughts. Very much appreciate the input. BTW can someone suggest who to talk to on the south coast preferably as an Onan agent please?

 

[david_bagshaw]

Berthons @ lymington supplied ours, quite some years ago. (self installed)