more electrical power out of a cucv system

[richingalveston]

just looking at ideas for more electrical power, I was checking on alternators and have found replacements for the 27si that can go to 200 amps or more.
They don't have isolated grounds so it does not help to get more 24v power but could provide more 12v power without sacraficing any of the 24v capacity.

If you replaced the drivers side alt. with a 200 amp unit and then split the output, one leg going to the passenger side alt to produce the potential 100 amps of 24 volt power
The second leg could go to the 12volt terminal block to which you would also connect an additonal battery (remove the connection from the front 24v battery)
This would give you a seperated 12volt system and allow total capacity of 100A @ 24v and 100A @ 12v. yes you would have 3 battteries.
This would also keep your 24v batteries equal to each other and get rid of the unbalanced battery situation.

I have not been able to find alts that have isolated grounds to replace the passenger side but if you can remove the 12v load to its own system you can utilize all 100 amps @ 24v. I would keep the starter and glow plugs on the 24 volt side but everything else can go to the 12v block

I realize the alts would not be interchangeable from side to side but that is not a big concern for me.

The cs130d can be built to output 200 amps and apparently you can get a special built ad244 that will do more than 300 amps
I don't need that much on the 12 volt side but if I can take all 100 amps of 24 volt power to an inverter that should power my AC unit.

the cs130d also provides 80% of its output at idle and 100% at high idle. not sure about the 27si output at idle still searching.

I welcome those with more electrical experience than me to help shoot holes in this setup.
Thanks
Rich

 

[reloader64]

A few (somewhat esoteric) questions come to mind.....

Will the belts slip under full load? And, will the engine idle under full load?

Serious question now-what will you be using 200-300 amps for?

Scott

 

[richingalveston]

looking to get all 100 amps out of the 24 volt system to go into an inverter for electric ac unit.
and 100 amps at 12 volt to run the truck 12 volt items. should not need all 100 amps at 12 volt unless i put a serious stereo system and that is not the plan

so using a 200 amp 12 volt alt. and the 100 amp isolated ground alt, you would get 100 amps at 24v and 100 amps at 12v.
you might get some belt slippage on the 200 amp 12volt unit but the 24 volt alt would be the stock cucv alt

the engine should not have any issues. not any different than putting a ac compressor with the two alts.

 

[DeadParrot]

You can get a 24v alt with high output amps. No need for isolated ground. Keep the 12v alt that ties to vehicle ground. The 24v alt runs the AC and tops off both batteries while the 12v alt supplies the 12v system and provides any charging the lower battery needs that isn't provided by the 24v alt.

 

[richingalveston]

does the 24v alt fit the cucv alternator mounts and will it work on a v belt. i looked at some but they were serpentine belt and much bigger.
I know the cucv amulances ran the rear ac off of an alt so i was wanting to get more info on that system.
thanks for the constructive input
rich

 

[DeadParrot]

Found this link for a 22SI @ 24V. http://www.delcoremy.com/find-a-part/product-details/19020382

Supposedly the 22SI is a physical drop in replacement for a 27SI except for isolated ground. That link shows a 28SI @ 24v @ 110amp as an upgrade. No clue on pulley and double check rotation direction. Maybe a alternator shop has a 28SI core you could borrow for fitment experimentation.

 

[richingalveston]

https://www.qualitypowerauto.com/catalog.php?item=551

this is one I have considered. I need to stay with two twelve volt alternators. If I were to put in a 24 volt and keep one twelve volt it puts more stress on the belts. If I had a serpentine system It would not be a problem. Using two twelve volt alts allows me to split the load between two belts instead of putting a heavy load on one and very little load on the other.
The drivers side alt will have more load, it will have half of the 24V load along with all of the 12 Volt load where as the passenger side will only have half of the 24v load.
If I have all led lights then the 12volt load will be fairly small. With just the ac running, the 24v load should be about 60% of the 24V capacity when the compressor is running. I think a 200 amp 12Volt alt on the drivers side and the 100 amp 27si on the passenger side is all that will be needed.

 

[MarcusOReallyus]

just looking at ideas for more electrical power, I was checking on alternators and have found replacements for the 27si that can go to 200 amps or more.
They don't have isolated grounds so it does not help to get more 24v power

The isolation can be added to most alternators.

If you replaced the drivers side alt. with a 200 amp unit and then split the output, one leg going to the passenger side alt to produce the potential 100 amps of 24 volt power
The second leg could go to the 12volt terminal block to which you would also connect an additonal battery (remove the connection from the front 24v battery)

What do you mean, "split the output"? Electrically, this makes no sense.

 

[richingalveston]

splitting the output of the drivers side alt by taking it to the 12 volt terminal block (it actually already goes there) and add a seperate 12 volt battery then also feeding it into the second alt (which it already does).

Therefore you can take a 200 amp 12volt alt. on the drivers side and have 100 amps available for the 12 volt bus and third battery (basicly all of the 12 volt items in the truck) and the other 100 amps available for the second alt wich then would give you the full 100 amps of 24volt power when needed and 100 amps of 12 volt power when needed.

Of course you remove the feed to the 12 volt bus from the first battery in the 24 volt system. You would also have 3 batteries.

By doing this you would have a true 100 amps of 24v and an additional 100 amps of 12 volt power instead of the current situation where you loose 1 amp of 24volt capacity with each amp of 12 volt power you use.

All that is needed to accomplish this is wire in a third battery to the 12 volt terminal block (neg going to 24v neg bus bar) and replacing the drivers side alt with one that can produce 200 amps at 12 volt.
This would also keep the 24volt batteries balanced.

 

[ken]

There are 24Volt inverters out there. I got a used one a few years back that is a 3000W. Its can easily run my 8000BTU window unit I have for the sliding rear window of my 1028. My window unit is only 850W. I wired it to the 24V buss on the firewall behind the batteries. I mounted the inverter behind the seat so the AC could plug in easily. I installed a VDO voltage gauge in place of the original and It never drops below 28V even when the AC kicks on. Even at 12V a stock 27SI would be 1200W. But mine put out 14.6V each. So In theory it would be 1460W. Multiply that times two at your at 2920W. More than enough power to run the truck/lights and almost any window unit AC. Now I do realize this is the redneck way of installing a AC in a CUCV but is sure works good. You might check into roof mounted AC for industrial equipment. Most are 24V and you could bypass a lot of work that way. There are units that are self contained so all you need to do is cut the hole in the roof and run the wires to the 24Vbuss on the firewall.

 

[richingalveston]

thanks for the reply, I am looking at the rv roof top ac units, I have not found any that were direct 24volt. most of those that are, are freezer units. I will look some more but the smallest rv roof top ac unit is 9000 btu with two speed fan and it only pulls 13.5 amps at 120v so yes I have believe the electrical system will handle the load. I am still looking for more options. I will search some more for 24v ac roof top units.
Thanks
Rich

 

[richingalveston]

I did search some more and found some 24V dc roof top air conditioners but they are pretty pricey and are not here in the U.S. so I think shipping would be expensive also. I also had some time to think about it and I beleive I am better off with a 120v unit with an inverter. I can then plug into the house or run it off a generator which is one of my main reasons for using a roof top unit and not getting a vintage air system or other. To use a 24V dc unit I would have to buy a converter to use the 24V unit while camping and they are more expensive.
The 120V unit and inverter is also the cheapest option. Total cost is approx. $1000 to $1200 depending on the inverter chosen. I can get the ac unit for $600.