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View Full Version : Those of you with INVERTERS.........



Maverick
03-21-2003, 23:22
My Cobra HG PI2000 inverter showed up today. Its 2000 watt continuous and 4000 watt peak. I am going to mount it on the front of the rear under seat storage box in my ex-cab behind the drivers seat. My question is would it be OK run the ground cables to one of the seat bolts instead of running them to the engine compartment? This inverter uses 2 ground and 2 positive cables. Would it be OK to hook both positive cables to the red junction box instead of to each battery? What would be a good in-line fuse (how big?) to install with this set-up? There is no recommendation in the instructions. Thanks.

Diesel Freak
03-22-2003, 00:00
Maverick, are you certain that thing is capable of 4000 watts??!! WOW! 4,000 watts is nearly 300 amps! Amps=watts/volts. Using 13.8 volts to figure from. For that kind of power you should pull direct from the battery and you need to use very large cable. Your continous load will be about 150amps, so you should use a 75 to a 100 amp fuse on each of the power lines. I have a 1,750 watt inverter, and the instruction say to run the power and ground direct to the battery for best performance. Do you need to have that much power available? I've found from past experience to just power a 21" TV & DVD, my little 300watt inverter does a great job, plus I get over twice the battery life compared to the big inverter. I will tell you that the batteries in our pickups won't stand up to well to pulling that kind of amperage off of them they're just not designed to put out a continous 100amps or so, plus your alternator will be workin it's butt off to keep up. I had an array of golf cart batteries in my 5th wheel when I was using my big invertor and still didn't get a heck of alot of run time at full load (microwave etc.)

Hope this helps! :D

GBurton
03-22-2003, 00:09
Hi Maverick

WOW, that's an inverter!
Let

TimofCharlotte
03-22-2003, 00:14
I've not installed one of these, but for purposes of figuring the running amps, I would think it would make more sense to calculate the watts/volts using 120 volts (AC) not the typical 12-14 DC volts generated in the truck electrical system. That would bring the current levels down to a more reasonable (yet still fairly high) 33 amps, more than enough to run alot of stuff with.
How much did you pay for it?

[ 03-21-2003: Message edited by: TimofCharlotte ]

[ 03-21-2003: Message edited by: TimofCharlotte ]</p>

pinehill
03-22-2003, 01:54
GBurton has provided the correct numbers for load current sizing on the DC side, the side you need to be concerned about.

Another consideration is heat dissipation. That inverter, at anything approaching 2Kw, will get quite hot, so locating it under a seat will be a problem unless you fan cool it very efficiently.

After installing this humongous unit, you'll be able to install a hot tub in the truck bed and heat it electrically. ;)

IndigoDually
03-22-2003, 10:00
I'd buy a couple of sets of Wally World jumper cables and cannibalize the cable from them to make Your hookups. At least these cables are paired up already, just don't get the polarity mixed up.

John

Maverick
03-22-2003, 10:35
Thanks guys.

The reason for getting this unit was the excellent price. $319 with a $80 rebate for $239. Thats a great deal.
I dought I will ever run it at full peak but you never know. Cobra supplys the inverter with dual 4 ga. cables that are 6 ft long. I think they will be to short. They say the longer run of wire would require going to maybe 2 ga. wire. They also stay away from aluminum wire as it has 1/3 more resistance than copper wire. I think Indigo has the right idea here. I have some good 4 ga copper jumper cable that I can use. The close bushing idea is good and will go Brown Electric today. GBurton, I will try to find a huge fuse there also. Pinehill, this unit has dual fans built in and will be on the front side of the storage box. I will have good air flow in this area. Good idea with the hoy tub also! :eek: Sounds like my biggest broblem is getting a fuse to work.
I am also getting the dual alternater set up. Parts have been ordered and should be here anyday. Hopefully this helps refresh the batteries alittle.

richp
03-22-2003, 16:32
I would second emphatically the need to keep your cables as short as possible and be sure to be amply fused. You don't want several hundred amps of red-hot, heavy duty copper wire under the seat of your truck all of a sudden.

I run a 1500 watt (3000 surge) inverter in my fifth wheel trailer and cannabalized an old set of jumper cables for my feed, which I was able to keep about two feet. I located an appropriate in-line fuse from a solar energy source in Arizona (sorry, can't find the receipt anywhere). I also put (and would urge you consider) a positive battery cutoff switch on the positive side of the feed to the inverter -- ideally somewhere where you can get to it easily. Some of these inverters pull a small load even when they are turned off at the switch on the inverter itself.

For what it's worth.

Rich Phillips

trout49
03-22-2003, 18:38
I think this might be the solar electric place in Arizona. They sell inverters up to 3000 watts.

http://sitelevel.whatuseek.com/query.go?slice_title=This+Site&query=inverter&B1=Search&crid=4a5b370f38e27131

I'll bet they could answer any question you might have.

ski
03-22-2003, 21:29
Just to add my .02, I would also add a capacitor in the loop from the battery (or each one !) I have been involved in many "voltage draining" audio installs involving many amplifiers and other devices, the cap keeps the load constant.

Marc

Maverick
03-22-2003, 21:46
Thanks for the link Trout.....they sell the brand I bought so they should be able to help me out. They call it a "catastrophe fuse" and I can get it in 200 to 450 amps.
I just installed a set of Luverne stainless tube steps on my 2500HD. Looks nice. Next up is the dual alts, inverter, and LCD TV. Need the inverter so I can play Playstation Nascar Thunder 2003 while going 80mph on the interstate. :D

chevmeister
03-22-2003, 22:01
for the fuse try chrutchfield or any stero place that sells high power equipment i have a 200 amp fuse and fuse holder that i got through crutchfield, they can get you all the power hook up stuff
Fuse
http://www.crutchfield.com/cgi-bin/S-GOMHXZ2IvW7/ProdView.asp?s=0&c=11&g=717&I=575RP7320&o=m&a=1&cc=01&avf=Y
Fuse holder
http://www.crutchfield.com/cgi-bin/S-GOMHXZ2IvW7/ProdView.asp?s=0&c=11&g=716&I=575RP7153&o=m&a=1&cc=01&avf=Y
Wire
http://www.crutchfield.com/cgi-bin/S-GOMHXZ2IvW7/ProdGroup.asp?c=11&s=0&g=718&cc=01&avf=Y
you want 1/0 gauge

oyazi
03-22-2003, 23:29
I'm in the midst of putting a 1200W continous in mine. I've installed a Blue Sea Systems Maxi Fuse block from West Marine on the eng compartment firewall near the aux battery. 175A fuse was selected and have another 200A fuse on hand. They run 8.50 apiece and available up to 350A. I purchase the longest battery cable I could get at Wally world and ran it from the primary battery to the aux battery and then to the fuse block. Then found some super flexible 2AWG welders cable at our local welding shop and ran it from the maxi fuse block, under the truck to a Blue Sea Systems PowerPost+ battery connection post with distribution bus. Its at that point I will tie onto for inverter power ~ someday bye n' bye. Our plan is to have power to the rear of the truck. I've no interest in placing the inverter inside the cabin and of course the eng compartment is out. I'm thinking there will be adequate power for infrequent and brief MW usage. Will probably never see it to its 2400W surge spec. Right now, I'm a lil low on round tuits :D

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