Looking For Input On 24 Volt Systems

[Lug_Nut]

Automobiles and motor homes have a 12 volt electrical system. Conversion buses have a 24 volt system. Maybe high line rigs like the LADB, KADB, EXDP and MADP should be 24 volts. I realize this is more a chassis issue, so K-2 or at very least K-3 Spartan chassis's.
As this is a topic I'm going to write on in early August, I thought it would be great if I could get some helpful input on the subject.

Especially the K-3 with its soon to be 650 HP. The starters would operate at half the amperage and the cables would only be again half the size. After all, large engines generally come with 24 volt starters for that reason. My boat, for example is 24 volt. The engines and starters only come that way, it's 24 volt or pneumatic driven, no 12 volt choice at all.

So what are the advantages?

* All the wiring for the DC equipment is generally half the size.
* Inverting only requires half the DC amp input. (pretty substantial 150 amps 12 DC input to drive the microwave. 75 amps for the 24 volt.)
* Onboard equipment could be more specialized (a bonus for the manufacturer)
* Possibly better cold weather starts.
* Cooler running altenator for high amp loads.

Disadvatages

* Need more or bigger batteries for substantial amp hrs.

So, can anybody add to this or have any ideas?



Peter

[Lug_Nut]

Automobiles and motor homes have a 12 volt electrical system. Conversion buses have a 24 volt system. Maybe high line rigs like the LADB, KADB, EXDP and MADP should be 24 volts. I realize this is more a chassis issue, so K-2 or at very least K-3 Spartan chassis's.
As this is a topic I'm going to write on in early August, I thought it would be great if I could get some helpful input on the subject.

Especially the K-3 with its soon to be 650 HP. The starters would operate at half the amperage and the cables would only be again half the size. After all, large engines generally come with 24 volt starters for that reason. My boat, for example is 24 volt. The engines and starters only come that way, it's 24 volt or pneumatic driven, no 12 volt choice at all.

So what are the advantages?

* All the wiring for the DC equipment is generally half the size.
* Inverting only requires half the DC amp input. (pretty substantial 150 amps 12 DC input to drive the microwave. 75 amps for the 24 volt.)
* Onboard equipment could be more specialized (a bonus for the manufacturer)
* Possibly better cold weather starts.
* Cooler running altenator for high amp loads.

Disadvatages

* Need more or bigger batteries for substantial amp hrs.

So, can anybody add to this or have any ideas?



Peter

[BOB E]

I custom built my own truck conversion. It's 43' long, therefore requiring a lot of long wiring runs. The cab & chassis is 12V however, I decided to go 24V DC to power the motorhome.

The advantages I contemplated were: less line loss in long (wiring) runs, more efficient inverter operation, more efficiient component operation, reduced heat in wiring & components.

I found most 24V components were comparable to 12V in price.
Items like solar panels can be configured for 12 or 24V operation, I wired most of my DC lights in pairs (series) as the fixtures I selected were 2 bulb or 4 bulb so this was easy.
LED lights required an additional 150 ohm resister to provide the correct voltage drop.
A few components were not available in 24V (such as the Big Foot levelers & slide-out motor) so I wired them through the 12V truck chassis system.
These are intermittent duty, and the truck battery bank consists of 4 group 31's, so there is plenty of amperage available to operate them.
The motorhome battery bank contains (8) six-volt golf cart batteries which seem to run everything quite nicely.
I installed a 120V AC high efficiency refrigerator, microwave convection oven, coffee maker etc, . . . all of which run off of a 3600 watt inverter/smart charger when we dry camp. Also installed 4 Seimans 100W ea solar panels. On most days, it is't necessary to run the generator.
I do need the gen to run the air conditioning.

I also carry a 2400W Yamaha inverter-generator and use it to recharge to motorhome batteries on cloudy days.
We only use the (chassis mounted) 10KW diesel gen if it's extremely hot.
Even though it made the elerctical system somewhat more complicated, I feel it was worth it to go 24V. I don't think a 12V layout would have provided enough wattage to run the refrig & other appliances without adding more solar and (believe it or not) I'm running out of space on the roof!

[Route 66]

Duplicate thread.

Other thread HERE.