Adding a generator

[Mick and Maggie]

I have been looking at those small portable 3kva generators (Diesel and Petrol) on eBay. We want one for use with a compact washing machine that we are going to add to the boat. I was going to add a separate supply feed from the generator just to the washer. The idea being to set up the generator on the tow path whilst the weeks washing is done. But then I started thinking about this a bit deeper and I wondered if anyone had ever converted the generator off one of these devices to be mounted in the engine bay and powered by the boat engine whenever needed. That way we could do a wash on the fly whilst moving.

 

I wondered what the issues might be around such a conversion.

 

Regards

 

Mick and Mags.

[blodger]

I think travel power mains alternators have been used successfully on canal boats but have not heard of anyone cannabalising a gennie and adding it to their engine to do so.

Many utilise an inverter of sufficient wattage to run the washing machine whilst the engine is running and driving sufficient capacity alternator(s). I do with the 'studio' Candy, even heating the water as it does not seem to draw from the hot connection for whatever reason.

[Robbo]

I have been looking at those small portable 3kva generators (Diesel and Petrol) on eBay. We want one for use with a compact washing machine that we are going to add to the boat. I was going to add a separate supply feed from the generator just to the washer. The idea being to set up the generator on the tow path whilst the weeks washing is done. But then I started thinking about this a bit deeper and I wondered if anyone had ever converted the generator off one of these devices to be mounted in the engine bay and powered by the boat engine whenever needed. That way we could do a wash on the fly whilst moving.

 

I wondered what the issues might be around such a conversion.

 

 

Like a 240volt alternator?

Edited September 8, 2010 by Robbo

[Chris Pink]

The first argument against a 240V alternator is cost, the 3kVA generators are pretty cheap.

 

I have seen diesel generators installed in engine bays, can be a bit of a squeeze but there are no intrinsic problems with installing a diesel set, all you really need is a filtered, pumped or gravity fed diesel feed and an lagged outlet for the exhaust. Some kind of elastic mounting will also be beneficial. You will need to ensure airflow if the set is air-cooled.

 

On the other side, you are reducing the versatility of the generator, it will no longer be portable.

 

The issues with a petrol generator and safety make it a non-starter.

[Robbo]

The first argument against a 240V alternator is cost, the 3kVA generators are pretty cheap.

 

Although expensive a 240v alternator wouldn't be as much as a standalone diesel generator. Installing should be easier as well especially if space is an issue. A diesel generator of course would be better, mainly due to not having to run the main engine and I believe (although have no experience) the sine wave is better?

[nb Innisfree]

Adding a 230v alternator requires the engine to run at a constant speed, too complicated considering the need to vary speed while cruising/locking and differing electrical loads. The other way is to augment with lots of electronic stuff like an inverter, easier to fit an Electrolux travel pack which has all this designed in. Simpler still to just have a large 12/24v alternator charging batteries and a separate inverter, completely flexible as regards engine speed.

Edited September 8, 2010 by nb Innisfree

[hughc]

If you have a PRM box fit a trolling valve which allows the engine to run at a constant speed whilst the prop. speed is varied.You can then gear an alternator to run at 1500 or 3000 RPM connected to the engine via a clutched belt drive. Regards, HughC.

[Robbo]

Adding a 230v alternator requires the engine to run at a constant speed, too complicated considering the need to vary speed while cruising/locking and differing electrical loads. The other way is to augment with lots of electronic stuff like an inverter, easier to fit an Electrolux travel pack which has all this designed in. Simpler still to just have a large 12/24v alternator charging batteries and a separate inverter, completely flexible as regards engine speed.

 

 

I thought the whole idea of a alternator was to provide a steady feed at no matter what revs it ran (above a certain revs of course)!

 

I agree though if the OP is cruising a lot then a inverter does seem the better solution than a generator or alternator. If not cruising a lot and space allows I would go for the diesel generator.

[bag 'o' bones]

Problems with engine mounted 230 volt alternators:

 

the engine needs to be running at a reasonable speed for the alternator to produce max power. So only any good when the boat is moving

 

Running the engine at tick over will not power the alternator sufficiently

 

Placing a electrical load on a engine at tickover will probably cause inefficient combustion causing engine problems eventually

 

For the engine to run at an optimum speed under load it would have to be disengaged from the gear box which is impossible on our boat and most others I imagine.

 

You would have to rig up some sort of speed up device when under load.

 

You would have to rig up some sort of regulator device.

 

The above is thinking out loud. thoughts based on my observations of a 4kw genset i'm using at the moment. I could be completly wrong of course!

Edited September 8, 2010 by bag 'o' bones

[deletedaccount]

Problems with engine mounted 230 volt alternators:

 

the engine needs to be running at a reasonable speed for the alternator to produce max power. So only any good when the boat is moving

 

Running the engine at tick over will not power the alternator sufficiently

 

 

This is not my experience. It works fine at tickover for me.

 

(like I say every time this thread comes up)

[Gibbo]

A few seem to be getting a bit confused here.

 

A 230 volt alternator has to be run at a constant speed. 1500 or 3000 RPM. If it runs at a different speed the output frequency will be wrong and things will start to go bang. They are nothing like a normal 12/24 volt alternator.

 

There might be some mileage in trying the same thing with an "inverter generator" because they don't have to run at constant speed. That's effectively what the Travelpower is.

 

Running the engine at tick over will not power the alternator sufficiently

 

It will if it's installed properly with the correct size pulleys. The problem is that many companies don't install them properly.

 

Properly installed they produce full power at engine tickover. By definition, if it won't do this then it was installed incorrectly.

[bag 'o' bones]

This is not my experience. It works fine at tickover for me.

 

(like I say every time this thread comes up)

 

I see where your coming from but like I mentioned my observations are based on a geneset which whilst can run at a slow speed it requires a certain amount of engine revs to get the electricity flowing. The only thing I can think of is on a narrow boat the alternator is geared differently via the belt

 

A few seem to be getting a bit confused here.

 

A 230 volt alternator has to be run at a constant speed. 1500 or 3000 RPM. If it runs at a different speed the output frequency will be wrong and things will start to go bang. They are nothing like a normal 12/24 volt alternator.

 

There might be some mileage in trying the same thing with an "inverter generator" because they don't have to run at constant speed. That's effectively what the Travelpower is.

 

 

 

It will if it's installed properly with the correct size pulleys. The problem is that many companies don't install them properly.

 

Properly installed they produce full power at engine tickover. By definition, if it won't do this then it was installed incorrectly.

 

But am I right in saying that boat engines don't like running at tickover speed for long durations especially when under load?

[nb Innisfree]

I see where your coming from but like I mentioned my observations are based on a geneset which whilst can run at a slow speed it requires a certain amount of engine revs to get the electricity flowing. The only thing I can think of is on a narrow boat the alternator is geared differently via the belt

 

 

 

But am I right in saying that boat engines don't like running at tickover speed for long durations especially when under load?

 

Long periods of running at tickover if temp hasn't reached optimum isn't really recommended, modern industrial engines are quite tolerant of this but they really need to be run under load at highish revs for some of the time with an occasional burst of max revs. Though our alternator will give nearly full output at tickover (1100rpm) the engine's not really happy especially when cold so I put extra revs on until it's warmed up a bit and charge rate has dropped off a bit.

Edited September 8, 2010 by nb Innisfree

[bag 'o' bones]

From what I can make out fitting a 230 volt alternator to a narrow boat engine isn't satisfactory whichever way you look at it, hence why most boats use the 12 volt inverter set up instead.

[RLWP]

If you have a PRM box fit a trolling valve which allows the engine to run at a constant speed whilst the prop. speed is varied.You can then gear an alternator to run at 1500 or 3000 RPM connected to the engine via a clutched belt drive. Regards, HughC.

 

Does that actually work Hugh? I thought the trolling valve allowed the clutch plates to slip for occasional usage, so used like this all the time won't it wreck the plates?

 

Richard

[deletedaccount]

In neutral (where I leave it to charge batteries/run the travelpower) my engine runs at about 800rpm. I'm guessing this is a bit slow, right?

[Mick and Maggie]

Thanks for the feedback.

 

We have a 1600 watt victron available to provide 230v AC - but a compact washing machine such as the Zanussi 1300 or the Candy would be a bit to much for the device.

 

My reason for using an alternator from a generator tied to the engine was because I have seen a number of them for sale on eBay. One or two have had engine problems but the generator was said to be ok. They come up from time to time and sell for 30-60 pounds for one in the 2.5/3 Kva range.

 

From what I have been able to find elsewhere on the net, it would seem that there are two forms of the portable generator – One is done as direct AC and using a single pole from a three phase alternator, speed is pretty well fixed at around 1500 rpm to create a 50hz output. However, the waveform is not a pure sinewave and can cause problems for electronically controlled devices.

 

The second form is not engine speed dependant and uses a single phase alternator rated between 100 and 120 volts AC output, which is then converted to DC. The waveform and output voltage conversion back to 230v AC are done through an electronic control panel. However, the waveform is a much better approximation to the correct waveform. The engine speed can vary quite a bit. However, at the lower engine speeds current output (Amperes) is somewhat limited.

 

However, I am tempted to go the usual stowed away until needed diesel generator route.

 

But thanks for the replies so far.

[Robbo]

We have a 1600 watt victron available to provide 230v AC - but a compact washing machine such as the Zanussi 1300 or the Candy would be a bit to much for the device.

 

Depending on which model Victron you have, you can add another and put them in parallel to provide more watts.

Edited September 8, 2010 by Robbo

[hughc]

Does that actually work Hugh? I thought the trolling valve allowed the clutch plates to slip for occasional usage, so used like this all the time won't it wreck the plates?

 

Richard

We have used the trolling valve whilst towing for short periods to avoid going in and out of gear in congested situations or waiting for locks.It is also useful in shallow water allowing the engine to run at a reasonable speed independent of the water depth or channel width.The valve used is ported differently to the standard PRM one and they assured me that as long as large amounts of power were not required for long periods there would be no damage to the box.The PRM 260 is the smallest box on which this valve can be used and when fitted to larger craft they are used for long periods whilst fishing. The engine should be limited to 1200rpm whilst the valve is in use so this may, depending on the load needing to be taken off, mean a fairly powerful engine. We use a Ford BSD3 which gives 42 BHP at 2200 so roughly 23 BHP at 1200 at full throttle.If the sums work out and you are confident about tackling the fitting then it seems to me that this may be a much cheaper and more reliable system than a Travelpower.It is obviously cheaper than a separate generator and the trolling valve can be switched out when the boat is stationary.Regards, HughC.

Edited September 8, 2010 by hughc

[nb Innisfree]

In neutral (where I leave it to charge batteries/run the travelpower) my engine runs at about 800rpm. I'm guessing this is a bit slow, right?

 

It depends on what size pulleys you have, 4:1 would probably give you plenty of charge but it depends if your engine is happy at that speed, if it runs smoothly without leaping about on the mountings then ok. Personally I would put extra revs on until it has warmed up a bit. I use our ammeter to decide on optimum speed when stationary.

 

Depending on which model Victron you have, you can add another and put them in parallel to provide more watts.

 

Can't be certain here but I think if you have a Multiplus you can parallel an ordinary Multi and both will then work as a Multiplus

[RLWP]

We have used the trolling valve whilst towing for short periods to avoid going in and out of gear in congested situations or waiting for locks.It is also useful in shallow water allowing the engine to run at a reasonable speed independent of the water depth or channel width.The valve used is ported differently to the standard PRM one and they assured me that as long as large amounts of power were not required for long periods there would be no damage to the box.The PRM 260 is the smallest box on which this valve can be used and when fitted to larger craft they are used for long periods whilst fishing. The engine should be limited to 1200rpm whilst the valve is in use so this may, depending on the load needing to be taken off, mean a fairly powerful engine. We use a Ford BSD3 which gives 42 BHP at 2200 so roughly 23 BHP at 1200 at full throttle.If the sums work out and you are confident about tackling the fitting then it seems to me that this may be a much cheaper and more reliable system than a Travelpower.It is obviously cheaper than a separate generator and the trolling valve can be switched out when the boat is stationary.Regards, HughC.

 

Thanks for that. I'm really surprised, but there you go. Always something new to learn here

 

Richard

[WotEver]

Can't be certain here but I think if you have a Multiplus you can parallel an ordinary Multi and both will then work as a Multiplus

I note from a press release I received the other day that Victron are now doing a 10kW Multiplus, and you can parallel up to six of them in single or three phase configuration. So if you want a nice workshop on your floating battery farm you can have a 60kW 3 phase setup.

 

 

Tony

[Graham Bowers]

Adding a 230v alternator requires the engine to run at a constant speed, too complicated considering the need to vary speed while cruising/locking and differing electrical loads. The other way is to augment with lots of electronic stuff like an inverter, easier to fit an Electrolux travel pack which has all this designed in. Simpler still to just have a large 12/24v alternator charging batteries and a separate inverter, completely flexible as regards engine speed.

 

Hi Chris :-)

I'm still in "planning" mode, so is your 24V alternator marine / expensive or lorry / affordable please?

Oh, and do you use a special controller?

Graham

[nb Innisfree]

Hi Chris :-)

I'm still in "planning" mode, so is your 24V alternator marine / expensive or lorry / affordable please?

Oh, and do you use a special controller?

Graham

 

Hi Graham

 

It's a Leece Neville 100 amp, £300! Got it from Middletons of Manchester. Bit pricey but butch enough to do the job, runs and charges ok off 2:1 pulley ratio, double v belt never needs adjusting. It's manual excitment but I find that an advantage being able to delay until engine is started and running. Disconnected both our controllers (Adverc & Sterling pro Dig)and haven't noticed any difference!

Edited September 8, 2010 by nb Innisfree

[Guest]

Hi Graham

 

It's a Leece Neville 100 amp, £300! Got it from Middletons of Manchester. Bit pricey but butch enough to do the job, runs and charges ok off 2:1 pulley ratio, double v belt never needs adjusting. It's manual excitment but I find that an advantage being able to delay until engine is started and running. Disconnected both our controllers (Adverc & Sterling pro Dig)and haven't noticed any difference!

Now there's a shock