Inverter location DILEMA!!

[Sgt Hulka]

(Note I am converted to pure 12v) I mounted my 3000 watt inverter under the passenger seat on my M1009, relocating the jack and lug wrench. I ran power to it from the blocks on the passenger side wall of the backseat area. I have it oriented with outlets facing the door. Used it during a blackout here in California to power two refrigerators the other day...

 

[Keith_J]

Wouldn't have made any difference, as far as I can tell at least. I've stripped the interior down to bare metal. There are NO wires rear of the dash, unless they're hidden inside the body somewhere with no outlet into the cabin. There are no capped harnesses, cannon plugs, or even "I wonder where that goes" open holes in the cab. I'm not sure what my M1009 was used for in the past, but it's possible extensive radio work wasn't it.

As for mounting it under the hood and running extensions, I don't want to do that because it has a USB slot on the face, and that's PERFECT for plugging in an iphone charger without having to screw with that dumb little plug-in cube thingie.

If you have a real M1009, the alternators are wired in series and are each 12V, making the 100A, 24V charging system.

By running the inverter off only one battery, you are asking for trouble. The voltage depression off the one battery will force both alternators to charge which will over-charge the other battery.

 

[Napoleon_Tanerite]

If you have a real M1009, the alternators are wired in series and are each 12V, making the 100A, 24V charging system.

By running the inverter off only one battery, you are asking for trouble. The voltage depression off the one battery will force both alternators to charge which will over-charge the other battery.

any good way to draw 12V in a balanced manner? Perhaps tap a 24v and use a resistor similar to how the glow plugs work, or am I asking for excessive heat doing something like that?

I still haven't installed this thing, I've yet to find a good location.

 

[Ken_86gt]

Using a resistor will not work for you. This only works for the glow plugs if the power dissipated by the resistor matches the glow plugs- this is why if one glow plug goes bad the rest are soon to follow as the voltage will no longer be balanced. The alternators are matched to each battery, there will not be any issues with charging as long as the alternators work.

Since you have a 1200W inverter, the lowest possible current draw at full load would be 100 amps at 12V. It will draw more as it is not 100% efficient. As noted above one alternator is rated at 100 amps, which is at the limit.

 

[Keith_J]

any good way to draw 12V in a balanced manner? Perhaps tap a 24v and use a resistor similar to how the glow plugs work, or am I asking for excessive heat doing something like that?

I still haven't installed this thing, I've yet to find a good location.

Put it on the SECOND battery. This way it will draw on the relatively unused battery. As long as both alternators are working properly, this will be a safe balanced load.

You MUST run a line from the intermediate battery connection (it is at 12 volts with respect to ground as the negative, never touching ground. And a lead from the 24 volt terminal on the firewall.

You need 8 AWG wire, no longer than 10 feet. Any longer up to 14 feet and you need 6 AWG. 4 AWG will get you to 20 feet.

 

[Ken_86gt]

You MUST run a line from the intermediate battery connection (it is at 12 volts with respect to ground as the negative, never touching ground. And a lead from the 24 volt terminal on the firewall.

If you do what he is saying you are basically running your inverter independent of the vehicles body ground- you are setting yourself up for possible short conditions as the entire inverter will have to be isolated from ground. You will not be able to mount it to the vehicle without electrically isolating it. This method would seem to me to be the most difficult method. It does not do anything really to help you. Connecting the inverter off of the normal 12V battery would be significatnly safer. Perhaps I missed something in your thread- are you needing 1200W of power all of the time? If not, it won't matter much. If you are really concerned about having enough power why not convert your alternator to a high output one?

 

[Ken_86gt]

After reading this thread again I see that you may want to run a 950Watt air conditioner. I doubt that a 1200W inverter will start that load. Most motor loads require 6-9 time the rated current to start up. Will that inverter deliver that much? I suspect that you would need a much larger one. If you really want power why not install a 120V 4000W belt drive generator on the engine.

 

[AllenEM]

Fabco Power - Hydraulic Driven Generators HYDRO - 350X

 

[Dodgeman1941]

Hi Keith,

Not to argue with you, but the alternators and the batteries opperate seperatly on the normal cucv's like the m1009. The first alt charges the first bat and the second alt charges the second bat. That is what is nice about this charging sysem vs the 24v system in the other MV's like the M35. That is why they can get away with pulling the 12v from the first bat. You can't pull 12v off from a m35 because it charges the 24v as a whole and can not break it into seperate, useable 12v sources w/o making the demand unbalanced that is why alot of Fire Departments struggle with M35's.

 

[Keith_J]

Yes, all but the 200 ampere CUCVs have split leg 24 volt systems. But that A battery alternator gets the most load, the B alternator only has to charge the battery after starter and GP loads. Which is why it is better for a 12 volt driven inverter since any loads here will not cause dimming of the lights and other issues.

The inverter must be mounted isolated from the chassis ground.

 

[cucvTater]

Excellent read from several posts. I am looking at doing something similar. I plan to take out the bench seats from my 1028, add buckets, fridge and large power inverter on back cab wall.

 

[motormayhem]

Im installing one as well but just a small one and am putting it under the dash and then installing an outlet under the 24v jumper up front and one where the ash tray is.

 

[notsosanestan]

what type of 24 volt inverter would be good to mount on the passenger side fender well where i could connect it to that radio power

 

[Sgt Hulka]

You'll need a "converter" ahead of the "inverter." If you intend to run 12V equipment...

 

[notsosanestan]

i dont get what u mean? im under the impression that a 24v inverter converts 24v into 110v just like a 12v one.

thinkin about getting this http://www.dcacpowerinverters.com/itemdesc.asp?ic=ML900-24

 

[motormayhem]

i dont get what u mean? im under the impression that a 24v inverter converts 24v into 110v just like a 12v one.

Correct, just wire it to the 24 power rail and it will work. No idea on what inverter, but you wont need a converter.

 

[Sgt Hulka]

I was presuming a 12v input inverter...