Cummins 6B generator options

[stone beach]

On my relatively small boat I am considering whether to upgrade the existing main engine alternator and run everything I need from the house batteries through an Inverter or to instal an additional 120v auxiliary generator driven from the main engine with additional belts etc

Of course installing a gen set would be best but short of space

Can anyone point me at equipment readily available for the alternatives please

 

[Capt.Bill11]

Honda portable generator that you keep on deck perhaps.

And remember any 120v generator you drive off your many engine has to turn at the correct speed to product 60 hertz. So you can only produce AC current at that one speed.

Unless you use something like an engine driven inverter system.

 

[N4712]

We had a Sea Power engine driven generator, it was a big POS.

 

[Aquabelle]

If you have a small boat, a large alternator on the propulsion engine with all charge going to the House bank initially, coupled with as big an inverter (or inverter/charger combination) as you need, would be my vote over a genset, anytime. Unless you plan to run air-con when away from the dock...then a genset is your only choice & then I'd go with the portable Honda or equivalent

 

[Billylll]

If you have a small boat, a large alternator on the propulsion engine with all charge going to the House bank initially, coupled with as big an inverter (or inverter/charger combination) as you need, would be my vote over a genset, anytime. Unless you plan to run air-con when away from the dock...then a genset is your only choice & then I'd go with the portable Honda or equivalent

The problem with the Honda units is they will only run a single 12,000BTU typical marine air condition unit. I have found you need close to 5kw to run larger AC units and still be able to keep up with the DC chargers house loads. I'm all for a quiet 1800rpm diesel generator that is sized close to 5kw or more depending on your # of AC units and additional AC loads like the house bank charger. Now the ideal generator would have at least 40-50 amps of DC available as well as the 5kw AC component.
Bill

 

[stone beach]

Dont want to comment much on the various opinions ... I am really just looking for some pointers for the equipment readily available for the alternatives.

By this I mean details of suppliers for the higher output (replacement) engine driven generator & regulator, make / model details etc. I noted the slipping belt details from frydaze recent post, dont need to discuss that aspect.

If anyone has a mains generator added to their main engine then make / model details would be helpful and if anyone has added drive belts to their 6B non drive end some details would also be interesting...but, for the reasons Capt Bill11 gives in post#2, I probably will not be going that route

Aquabelle's method in post #4 is more how I envisage it

 

[DavidM]

You have a Cummins 6B, right?

The Cummins uses a Delco as its OEM or maybe a Leece-Neville and has a 2" single foot mount. These are available at up to 180 or so amp ratings with connectors for an external regulator which you will need for good output. The Balmar ARS5 regulator would work fine.

So with potentially (and I say that because engine rpms and alternator temps will reduce this) 180 amps of power at 12 volts then you have 2,000 watts of power generation available.

You obviously understand about the belt wrapping solution which you will need with 180 amps of load.

A second alternator will be expensive and it won't be a 120V unit for the reasons stated above- rpms and frequency. You could fabricate a mount for a second alternator and drive a 12V, large case, high output alternator. Balmar makes them and maybe Leece-Neville as well. But the fabrication work, the alternator and the regulator will cost several thousands of dollars.

You can buy the standard case, 180 amp Leece-Neville alternator on line but it will take some research to find the right one that fits your Cummins mount. Or you can pay more and buy the alternator from Balmar. You can buy the Balmar alternator or regulator from Defender or similar.

Come to think of it, I would buy a Balmar alternator and regulator. They understand marine applications and can get you the right pulley to work with your serpentine belt. Their alternators put out more real power than even heavy duty truck alternators such as the Leece-Neville.

But do you really need that much power. Are you doing this to run DC loads at anchor, in which case running your propulsion engine at anchor with a light load on it isn't a good idea.

Most power boaters can run their at anchor loads from a decent sized bank of batteries and then recharge them while underway a few days later. With the standard Hitachi 80 amp alternator on my boat, I get along fine this way with only 200 amphours of house battery capacity. I have never anchored more than 2 days at a time and my cruising time of 4-5 hours is enough to recharge fully afterwards. If I needed more output or less cruising time I would go with the Balmar alternator and regulator, but so far haven't needed it.

David

 

[Aquabelle]

Stone Beach: I have a Leece Neville 160A alternator on my stbd 6BTA5.9 370hp engine...photo attached. It required a simple locally made bracket, does not overheat even when working hard and is a fraction of the cost of a Balmar. This is described as a 'mid case' alternator; if you go as large as 180A bracketing becomes more complex/costly. It is externally regulated by a Balmar MC614-12 which is user-programmed to de-rate the alt by 15%. The 160A alt works with a smaller Bosch 120A alt on the port engine to charge a 920aH house bank....I wouldn't recommend the Bosch as it needs to be de-rated by 25% to stay at a safe temperature under all conditions. But the Leece Neville 160A would be a real option for you I believe

 

[bshanafelt]

you might check the archives about this.

You can fit a large frame alternator with an adapter for a j-180 mount sold by cummins. $40

This will fit in the same spot as your stock alternator although will be somewhat larger - make sure there is clearance in your engine room.

You may have to buy a new belt if you have to re-route. $40


You can buy brand new 180-200 amp large frame truck alternators on ebay for around $250 USD.
Use a Balmar regulator ARS-5 or better for $150.
Use a Balmar digital duo (or other ) to charge your start battery with surplus juice. $150

new cables of course to carry all those monster amps about your boat. $$

Don't forget to fuse things $$

you should also get temp sensors for both the alt and battery bank $$

What you will have in the end is a very robust DC charging system that will do a bang up job of keeping your batteries happy.

 

[Aquabelle]

+1 to the above! great summary

 

[timjet]

Call Tony Athens at SBMAR.COM
I believe he makes a kit for the 6B's that includes the brackets and 160 amp alternator.

 

[Capt.Bill11]

http://www.victronenergy.com/upload/documents/whitepaper-Engine-driven-inverter-system.pdf

 

[stone beach]

thanks to all for information & "leads"

 

[bligh]

dont forget solar panels and a battery bank as an option.