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2017 Silverado HD large inverter (3kw) install

51K views 74 replies 15 participants last post by  jdwarren  
#1 · (Edited)
I didn't see too much detailed information on installing a large inverter in one of these trucks, so I rolled the dice and just went about it the best way I could determine. I think it turned out reasonably well. It's not the cleanest install imaginable, but it's easily removed for vehicle trade-in or sale purposes. Note that I did this install late last year, and have since driven over 5,000 miles with absolutely zero electrical issues, so I think it's a sound installation.

I chose the AIMS 3kw inverter-charger because AIMS is a well-reputed manufacturer of this sort of equipment, and I wanted the charging capability because I am considering building a large power pack for my camper, and I wanted to get familiar with how these things function. Better to spend an additional $300 now then blow it on a $3,000 inverter later. However, for most vehicle inverter applications, the charging isn't really necessary unless you want to be able to run your vehicle's accessories off AC.

I also wanted auxiliary outlets in the truck bed, so I made sure I chose an inverter with hardwire terminals. In retrospect, I should have put the outlets and inlet closer to the tailgate so they could be accessed easily without climbing into the bed. I could move them, but I'd have to either run new wire to the inverter or install a junction box somewhere to make the connection because the existing wire isn't long enough.

The bed outlets are a standard 20A GFCI outlet and a NEMA L5-30R. I chose the latter to make this installation mirror what you'd find on a 3kw generator. For my RV I have an L5-30 > TT-30 adapter, and a TT-30 > 14-50 adapter, so I can connect my 50-amp plug to the inverter via the bed outlet and utilize the full 3kw (the draw on the 20A outlets should not exceed 2.4 kw). You could just as easily use a TT-30 outlet, though, if your only application is an RV.

Now, for the numbers. My truck has dual alternators, 220A and 150A, for a combined maximum output of 370A. I also had the high-idle software added to my truck by the dealer so I can raise the idle speed to about 1200RPM via the cruise control button, which would be a good idea if a large continuous load is to be placed on the charging system at idle. 370A * 12V = 4.4kw, so 3kw should be well within the system's capabilities, although I admit to being unfamiliar with the magnitude of thermal losses due to the DC/AC conversion. 3kw / 12V = 250A, so I needed cable/terminals/fuses that could handle this huge current. The 4/0 welding cable is actually right around its limit at that amperage, but it's readily available (as are terminals, fuses, etc.) so I decided it was the best solution. 3kw/120V = 25A, so I went with 10-gauge SOOW (flexible) cable for the AC connection to the auxiliary outlets and inlet. This cable can handle about 30 amps for non-continuous loads or 24 amps for a continuous load (80% of intermittent load capacity), which is close enough to the theoretical maximum 25A that I can draw from the inverter continuously. More cautious types could go with 8-gauge.

I thought long and hard about where to locate the inverter. Putting it in the bed would totally eliminate the issue of routing cables into the cab, but the inverter would then be exposed to the elements without constructing some elaborate (and space-consuming) enclosure. I decided to play it safe and located it under the rear passenger-side seat. The particular inverter I chose is very tall, and I was just barely able to install it such that it does not interfere with the seat or the foot room in front of it. It is not the most aesthetically pleasing location but hey, it's a truck. Also, this inverter's ventilation holes are on its sides, so I don't think the fact that the top of it is covered is a problem. I knew I would have to drill a hole somewhere, and I wanted it to be easily concealable, so I did it in the back of the cab below the rear seat. I used a hole saw and installed a 2-1/4" clamp connector to protect the cables; note that the one I linked to above is only 2" (can't seem to find the 2-1/4" on Home Depot's website). It was extremely difficult routing the cables through the connector; if I were to do it again, I would go with two smaller holes and clamps. I was able to screw the clamp down on the cables enough that I didn't feel like I had to use any sealant, but I guess you could use silicone or something to totally eliminate the air gap.

Some of you may be wondering about the dedicated neutral wire. For the amount of current that this system needs to be able to handle, I did not want to roll the dice on the resistance across all the body/frame/engine/alternator connections, especially since many of these connections are exposed to the elements and may be subject to increasing resistance through time due to corrosion, dirt, rock salt, etc. The other thing that may be odd-looking is the bond I installed between the two alternators' positive terminals. I did a continuity test from one alternator to the other with the truck in its original configuration and found that there's no resistance between the two (it's one continuous system), but I realized that the current path from one alternator to the other routes through small (relatively speaking) 2-gauge cables to each battery and then to the starter. So if I made the connection to only one alternator, the current path from the other alternator to the inverter connection would be alternator 2 > battery > starter > battery > alternator 1, all through those smaller cables which have no overcurrent protection and could become very hot if I were drawing a full 3kw from the inverter. Plus, the voltage drop could make the system unable to provide the full 3kw at all. Therefore, I bonded them together with a small length of the welding cable.

Aside from the hole I had to drill in the cab, the only really annoying part of the installation was routing the huge cables out of the engine bay. I had to remove the passenger-side battery to install the fuse block anyway, so while I was in there I pushed the cables through a small gap between the sheet metal that constitutes the fender. I then removed the wheel well shroud from outside (it's held in by little Torx screws) and was able to route the cables on the inside of this shroud down to the back of the passenger side front wheel well and have them pop out right next to the frame rail. From there I routed them over the running board anchors and secured them with zip-ties. I covered the exposed positive cable with wire loom as an extra added protection against the possibility of the insulation being compromised from road debris or some unforeseeable catastrophe. To secure the inverter to the floor I just used two 2-1/2" self-tapping hex-head screws from Home Depot and drilled right through the carpet and into the metal floor below (after checking under the cab about a dozen times to make sure I wasn't going to hit anything).

The install works about as well as I could have hoped. I am able to run a pair of 1500-watt space heaters off it simultaneously. I don't even have to use the high idle; as soon as the truck's electrical system detects the voltage drop (at that load, the alternators can't supply the needed current at idle so the batteries begin to deplete) it increases the RPM on its own. One thing I have not yet tested is starting my 15k BTU/hr air conditioner, which is an important test because the space heaters are resistive (as opposed to inductive, like the AC's compressor) loads and, as such, their starting current is no higher than their running current. Update: the inverter has no problem starting and running my 15k BTU/hr air conditioner, even while simultaneously powering my 1200-watt water heater, DC power converter, and refrigerator.

I may have forgotten some details, so if you have any questions feel free to ask. Rather than answer in a reply, however, I'll probably just add the relevant information to this initial post so that anyone reading this in the future will be able to find all of the info in one place.

Edit 1: A note on circuit breakers and fuses. I tried a 300A circuit breaker and it tripped under a load that I estimate to be about 230A. At that point I decided to go the simpler route of a fuse and block, and just deal with replacing the fuse in the (extremely unlikely) event that I ever blow one. Breakers can degrade over time, and my understanding is that they're designed to "fail safe," so they'll trip at lower, rather than higher currents than their rated capacity. I don't have detailed or technical knowledge of circuit breakers, so it would be interesting to hear others' experiences in this area.

Edit 2: For reference, the length of my cables (neutral and hot) is about 20 feet, for a total length of 40 feet from the hot side of the alternator to the inverter and back to the neutral side. Less is always better, as wire has finite resistance. Remember, P = (I^2)*R (where P=power [watts], I=current [amps], and R=resistance [ohms]). This means that your power loss due to a given resistance is going to be much greater if that resistance is on the 12 VDC side as opposed to the 120 VAC side. How much greater? Well, for a given value of P and R, the current on the 12 VDC side (upstream of the inverter) will be 10 times greater than the current on the 120 VAC side (downstream of the inverter). 10^2 == 100, therefore the heat (or power) dissipated across the same value of R (assuming a corresponding impedance on the 120 VAC side) will be one hundred times greater. Coupling this with the understanding that the cable or wire used to transmit the power has its own resistivity (resistance per unit length), it's easy to see why you're always better off locating the inverter as close to the DC voltage source as possible in order to minimize the length of cable that the low-voltage DC current has to flow through. You can always just use extension cords or hardwire some auxiliary outlets on the 120 VAC side. This is a much better solution than locating the inverter far away from the alternator(s).

Edit 3: If you are going to install something like this, I recommend doing a "bench test," in which you wire up your inverter with the correct-length cables, fuse block and/or breaker and anything else and load it under your worst-case scenario conditions, but before actually drilling any holes or routing cables. A poster below proposed the use of bulkhead connections instead of drilling a large hole in the cab; if you do this, make sure those bulkhead connections are used in your bench test, as those connections have finite resistance. Also, do not use bulkhead connections for any 120 VAC circuits! Doing so poses a major electrocution hazard.

Edit 3A: There is a discussion about the safety of using bulkhead conductors for 120 VAC somewhere between posts 10 and 20 of this thread. I maintain my recommendation -- in the strongest possible terms -- against doing this, but if you have a strong fundamental understanding of electromagnetism you may be capable of doing the requisite analysis to safely deviate from standard practices and implement this design.

Edit 3B: I've done some more thinking about the use of bulkhead conductors for 120 VAC circuits. I still think it's a bad idea, but it's not necessarily suicidal/homicidal provided that you are using GFCI for all your circuits and the inverter's ground terminal on the AC side is bonded to the vehicle chassis. This gets a lot more complicated if you are using an inverter-charger that may be connected to shore power, because you need to make sure that your inverter has an internal relay that breaks the chassis-neutral bonding when shore power is supplied. If it doesn't, then an open neutral connection on the shore power side could result in the vehicle chassis being energized at line voltage. In that scenario, if the inverter circuit is not GFCI-protected, you're basically asking for someone to be electrocuted. If what you just read doesn't make perfect sense, just drill the damn holes for your 120 VAC cables and insulation. ;)

Edit 4: A note on AC cable/wire selection. You could use Romex for the auxiliary connections, but solid-core cabling like Romex needs to be secured such that it's never really subjected to any kind of physical movement. The one advantage (aside from cost) to using Romex is that it's easy to connect to hardwire terminals. What I wound up doing was using outdoor-rated flexible SOOW cable, and then inside the auxiliary outlet and power inlet gangboxes I connected the SOOW to the outlets/inlets using a very short (three inches or so) length of 10/2 Romex and wire nuts. I did this because the stranded SOOW cable is difficult to insert into the hardwire terminals on the outlets/inlets. The gangboxes got pretty crowded, though. You could skip this and tie the SOOW in directly, but you need to be extremely careful about individual strands of the wire not seating fully and remaining exposed, as this nearly guarantees a ground fault (electrocution hazard!) or short circuit.

Edit 5: You will need serious cable cutters to cut 4/0 effectively and without creating a mess. The cutters I link to below will work, but something larger would probably be better. For stripping insulation I just used a sharp box cutter and was very careful not to cut any of the strands.

Edit 6: Here is a handy voltage drop calculator. My parameters are:

Wire Material: Copper
Wire Size: 4/0 AWG
Voltage: 14 (approximate alternator voltage)
Phase: DC
Number of conductors: single set of conductors
Distance: 20 feet (it specifies one-way distance, not round-trip)
Load Current: 250A

I get a voltage drop of 0.49V, which sounds about right as compared to my practical measurements. You can measure voltage drop at a specific inverter load by measuring V_alternator - V_inverter. V_alternator is the voltage measured across the alternator's positive terminal and its metal housing. V_inverter is the voltage measured across the inverter's positive and negative terminals. Both measurements need to be taken while the inverter is under load; i.e., the values will be different for different loads. Do this during your bench test. If your voltage drop is significantly greater than what the calculator predicts, take a look at your connections and any other resistive devices in the current path (fuse/block, bulkhead conductors, etc.) and see how bypassing them affects the drop. Of course, you can't bypass the fuse/block for the full install, but if you find that it's adding significant resistance you will realize ahead of time that there's some debris or other issue that needs to be addressed before you go any further; these issues are much easier to diagnose with all the wiring and other hardware exposed than post-install. Remember, if V_inverter drops below some specified cutoff voltage (probably 10.5 V), the inverter will shut itself off. And don't forget that resistance under load means heat dissipation, at a rate of I^2*R.

Below are links to some of the hardware I used for the install:

AIMS 3kw inverter-charger: https://www.amazon.com/gp/product/B00NZCRFRQ/ref=oh_aui_detailpage_o02_s01?ie=UTF8&psc=1
16-ton hydraulic crimper (the 10-ton is not large enough for the terminals I used): https://www.amazon.com/gp/product/B00GXQ2E5E/ref=oh_aui_detailpage_o01_s00?ie=UTF8&psc=1
ANL fuse block: https://www.amazon.com/gp/product/B000K2K7TW/ref=oh_aui_search_detailpage?ie=UTF8&psc=1
300A ANL fuses: https://www.ebay.com/itm/300A-AMP-A...ted-High-Quality-Fuses-6-Pack-Car-Audio-Blade-/173191129908?hash=item2852feeb34
4/0 terminals: https://www.amazon.com/gp/product/B00030CYU6/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
4/0 flexible welding cable (black): https://www.amazon.com/gp/product/B00KD27670/ref=oh_aui_detailpage_o02_s00?ie=UTF8&psc=1
4/0 flexible welding cable (red): https://www.amazon.com/Gauge-Premiu...F3T2BK5B12QHTF0Z&pd_rd_w=CI1XU&pd_rd_wg=igc4s&psc=1&refRID=EBQAF3T2BK5B12QHTF0Z
Heat shrink (red): https://www.amazon.com/gp/product/B01F2LG3JS/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
Heat shrink (black): https://www.amazon.com/gp/product/B01F2LGF5U/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1
3/4" wire loom (red): https://www.amazon.com/gp/product/B00TE1SCQU/ref=oh_aui_detailpage_o06_s01?ie=UTF8&psc=1
10/3 SOOW cord: https://www.homedepot.com/p/Southwi...oot-10-3-600-Volt-CU-Black-Flexible-Portable-Power-SOOW-Cord-55809799/204632922
15-amp power inlet (outdoor rated): https://www.gordonelectricsupply.co...BRBMEiwAmKSB8yYhMgcbfabQHNAQbLEU_3qj2oGwrS3G3vLhgB7sYfZ0Zmsd5hn4CRoCJMkQAvD_BwE
2-inch clamp connector (EXAMPLE -- see discussion above): https://www.homedepot.com/p/Halex-2...om/p/Halex-2-in-Non-Metallic-NM-Sheathed-Cable-Clamp-Connectors-05120/100127021
Cable cutters: https://www.homedepot.com/p/Pro-sKi...etj85Y1zKRneqqgkiAhkz4-2oOwdZrQNAaAgrvEALw_wcB&dclid=CIHVwZW8gNoCFYS9swodiUcOgQ

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Update: The install looks a lot cleaner with these Maxliner floor mats covering the cables routed under the back seat.

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UPDATE: I've since relocated the in-bed inlet/outlet to make room for my auxiliary fuel tank. This has the added benefit of making the inlet/outlet accessible while standing behind the tailgate. I definitely should have done it this way from the outset.

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#4 ·
Now I'm wondering if your RV AC will start and run.I have a 13,500 btu and was told a Micro Air Easy Start wired to AC unit will start and run off 1 Honda 2000 gen.You said AC is important so if you never heard of this maybe something to look into to start your AC unit.But I'd like to know if it's needed with your setup.Nice write up!
 
#5 ·
Thanks. I think what you're describing is a start capacitor that can be charged up at the continuous rate of the power supply and then discharge at a much faster rate to start inductive loads like compressors (or motors, more generally). My 15k BTU/hr AC will start and run on a 3kw generator even when connected with a crappy 16-gauge 100-foot extension cord, so I am pretty sure my inverter can handle the load, especially since it's rated for 6kw instantaneous (20-second, I believe) draw. The only question is whether my truck's batteries and alternators can supply that instantaneous juice without the voltage dropping below the inverter's cut-off voltage. Once the weather warms up I will try it and update the writeup accordingly.
 
#6 ·
Thanks Nate for bringing this to my attention. I haven't been over here on DF for a while.

I am installing a 1500w inverter in a semi truck to run a fridge and microwave. I would like a bigger one but I already have this one. I am using the same size welding cable you are but I have solder on ends instead of the crimp on. I was just going to come off the batteries and go straight into the sleeper. I see you went to the alternator.

Why didn't you just go off one of the batteries?
 
#8 ·
Two words: voltage drop.

I'm not planning on drawing any significant power unless the truck is running (and I don't suggest you do either, unless you have a separate battery pack and an isolator, a much more complicated system), so if I were to connect to the battery instead, the current would have to flow through the alternators' connections to the battery. As I pointed out in the OP, that connection is made using small 2-gauge cables; not nearly large enough to supply 250A continuously in a safe manner.

1500w/12V=125A, and at that huge current, even if you don't exceed the safe capacity of the 2-gauge cables, the voltage drop across them will probably be such that your inverter's low-voltage safety shutoff will be tripped. You can completely eliminate that problem by tying your inverter directly into the alternator(s).
 
#7 ·
#9 ·
I saw these too and considered going this route, but I wanted to minimize voltage drop. The bulkhead interface (especially the exterior one which is exposed to debris, moisture, corrosion, salt, etc.) will have some finite resistance associated with it. Now, I didn't try them so it may be so small as to be negligible, but I was comfortable drilling the hole so I went that route and totally avoided that issue. Note that if you want auxiliary outlets in your bed, I discourage you in the strongest possible terms from using bulkhead connectors to get 120VAC out of your cab. That would be a major electrocution hazard.
 
#12 ·
There are two main considerations when selecting the wire gauge for a particular application. The first is safety related and has to do with how much current the conductor can carry before heating excessively. When I was putting my home wiring together I was required to use a much larger gauge wire than the power company used on the overhead service. The power company installer said they were allowed to use smaller wire because it is air cooled and so not as likely to overheat. I suspect the fact that it doesn't touch anything either means it can run hotter without concern. In any event, the heating effect is related to the square of the cross section of the wire so heating drops pretty quickly with larger wire.

The second consideration is power loss or as some put it, voltage loss, along a length of wire. The calculation for this is relative to the diameter of the wire, the length of the wire and the current carried. More current or more length mean more voltage drop for a given diameter. This is related to heating but is a separate issue.

I don't mean to step on any toes here and you should do what ever makes you comfortable but the ideas expressed here are pretty conservative. You certainly will not go wrong with big fat wires but the same rules that apply to homes don't apply to trucks. It is the same thing about air cooling. If you have your wiring running under carpets or in enclosed spaces then home rules may be most applicable but if your wiring runs in the open then you can back off a bit on the gauge sizes from a safety standpoint.

I like breakers. Properly chosen electromagnetic breakers in a well designed box are what run most homes in this country. I've had to replace a breaker or two because they failed but they are pretty reliable overall. Fuses are reliable too but when they fail it is much more complicated to replace a fuse than to reset a breaker. It always seem that when it is time to replace a fuse there isn't one at hand.

I don't see the electrocution hazard associated with bulkhead connectors. With all of the kids sticking paperclips in sockets you would expect to see reports of massive deaths every night but it just doesn't happen. It is unpleasant to get zapped but the fact is that 120V is pretty safe. In Europe they use 240V and even they aren't dying in droves. There might be a small hazard to the vehicle due to the potential for a short but again it doesn't happen in houses very often so I don't see it as suicide in a truck.

If I did this, and I might, I would put the inverter under the hood, keep the high amp cables very short and run the 120V from there.
 
#13 ·
The voltage drop issue, aside from the (arguably negligible, as you pointed out) dangers due to resistive heating, is that most inverters are set up to cut off if the voltage across them drops below 10.5 VDC. So over-sizing the DC wiring -- again, not with regard to safety from a resistive heating standpoint -- can help with this. Precise measurements of resistivity (and hence resistance) for specific wire gauges might not be a bad idea, but are beyond the scope of my writeup.

As for breakers vs. fuses, I like the breaker idea, but I would definitely measure the resistance across the breaker and compare it to a fuse before making a decision. The impedance in a breaker may be negligible at 120 VAC but the corresponding resistance at 12 VDC means an order-of-magnitude higher voltage drop, or a two-orders-of-magnitude higher power loss due to resistive heating.

Regarding bulkheads for 120 VAC, having the (bare) 120 VAC conductor within a few millimeters of the vehicle chassis in an environment prone to moisture (especially since a water-salt solution -- with its reduced resistivity -- is not an uncommon finding in winter) or full submersion just does not seem like a good idea. I don't know exactly what the result would be of having a 120 VAC energized bulkhead conductor submerged in such close proximity to ground, and I won't speculate (this brings up the matter of whether to bond the inverter's ground to the vehicle chassis, which I did not address). But unless you've actually implemented this design and verified its safety I don't think you should endorse it. On the other hand, if there's a way to completely insulate the 120 VAC conductor in a watertight fashion, I will retract my skepticism.

Finally, I can't speak for other vehicles, but I challenge anyone to find a suitable place to mount a 3 kilowatt inverter in the engine bay of an L5P Silverado or Sierra. Mounting the fuse block was hard enough!
 
#16 ·
Question for the OP.

Wondering what type of "camper" you are using this with? Is it cab over, travel trailer or 5th wheel? Also why not just use a 3K generator? If you were running it strictly off a bank of batteries and didn't the noise I get that, but the truck makes noise any way, although probably less than a generator, and possibly less fuel.

Not criticizing your choice, at all, just wondering why you did it the way you did.

Also on pushing stranded wire into terminals, twist them together and solder the 3/8" or so you need to make it solid.

Nice job and nice write up, and I agree with you on isolating the 120v. It's not voltage that kills it's amperage, and 5ma across the heart will stop it.

If someone doubts, grab the + and - terminals of a 12v truck battery with one hand on each. Then report back, if able.

As for kids not dying when sticking a paper clip in an outlet? First off it's a 50-50 chance of hitting the hot wire vs neutral or possibly the ground depending on the clip. Second of all they may not have a good path to ground, which is what kills, it's the current path through the heart to ground.

In EITHER case it's not worth the risk, period, to not know you have a short to chassis, and find out when the wife or kid steps out, holding onto the truck, into a puddle of water.

I would like to see the rig set up and in use though. I have a 2K inverter setup on my 5th wheel but it is battery supplied (4-6v 232ah batteries) and cannot draw near the power you can, but I can use mine in after and before generator hrs and total silence.
 
#17 ·
I kind of just wanted to see if I could do it and get the full 3kw, and in that sense it was a success. I don't think I'll use the functionality enough to justify a 150 pound space-consuming generator, plus I'd like to be able to run my 1200 watt air compressor for inflating high pressure tires and high volume rafts. Both of those applications are short bursts of high current draw, so I figured the inverter would be useful.

As for the 12 VDC battery: I've grabbed both terminals of car and truck batteries many times to illustrate exactly the opposite of what you stated. ;) 12 VDC is not nearly enough voltage to induce current through both of your arms and torso; at that voltage the resistance of your tissue is effectively infinite. At higher voltages, electrical breakdown can occur, and this often results in electrocution. But it's not like voltage and current are separate and independent parameters of a system; current flows as the result of applying voltage. V=IR, but it turns out that R itself is actually a function of V, so it can get pretty complicated. But 12 VDC does not pose an electrocution hazard, although it can still burn you via resistive heating (it can even be used to weld, in a pinch).

Oh, and it's a travel trailer. And another cool capability would be running the AC in the camper while we are on the road, so our animals can ride in there while us humans occupy the truck.
 
#19 · (Edited)
Haha, no kidding. But I'm also planning on "eventually" doing something like this on a much larger scale for the next camper (which will be a large fifth wheel) involving a 12 kw 48 VDC inverter-charger (split-phase 120/240 VAC output) and a bank of AGM batteries. This power pack will require the same amount of DC current, so now that I've worked with the 4/0 cables and terminals I'll be a lot more confident going into that $5k+ project.

One application of the truck inverter I'm really looking forward to, though, is running my Porter-Cable air compressor for inflating rafts for river trips. Inflating two five-person rafts with a shitty little DC pump is painful and extremely time consuming. I suspect that my 2-CFM @90 PSI compressor will do it much more rapidly. The compressor is also great for inflating truck and trailer tires (100 ft extension cord gets it to the trailer axles with room to spare).
 
#20 ·
This is what I installed in my truck. https://www.ebay.com/itm/Puma-12-Vo...-Oiless-12V/252693385387?epid=2254404946&hash=item3ad5b310ab:g:LgkAAOSwA3dYXKjJ
Mine is a 1hp, they no longer sell. Rated 1.5cfm at 90 psi. 12v DC and is on a 40 amp circuit, powered from the battery through a relay, controlled by a lighted witch on the dash.

This is the second time I have done this with the same model compressor. The first was in 2002 on an '01 Jeep Wrangler we had. The motor has a 100% duty cycle and will air up an 80 PSI tire (265/75R16) from flat to 80 in about 2 min.

Just flat out pump and last a long time. Have not worn one out yet. Mine is mounted under rear drivers side door, tucked inside inner frame rail, tank and all, but separated from each other. Mine fills the 1.5 gal tank in a little over a min at 125 psi, where I have it set to cut off.

My batteries in my 5th wheel inverter setup are (4) US2200's in series parallel to 12v, for a total of 464ah. or 232ah usable going by the 50% rule. If I ever upgrade these it will be to lithium's. One single 200ah lithium will do what 4 lead acid batteries will do, safely, and last a lot longer. And for the RV it will weigh about half or less of the lead batteries.

After getting used to my Tesla Powerwall at 13.2KW powered by our 4.5KW solar panels, on our home, I am spoiled for lithium and their usable ah.
 
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#21 ·
This was the Jeep install. And the truck install. I did a thread on the truck install, but I had the pics on photobucket and they dumped everyone, and I never re-posted the pics.

I did a write up on the Jeep when I did it, and it was on a web site I used to run (handirifle.com, wonder where I got my name?) and the company I got it from off Ebay, used to refer folks to it for their builds. I since closed down the site and gave up the name, so that article is gone. I still have it, but just isn't on the web.
 

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#24 ·
Got the inverter in my truck done. Used 1/0 welding cable. Used a 150 amp fuse link. I had the guy at the welding supply store crimp on a couple ends for me. They were junk. Slipped right off. So I used some solder on ends.
I hooked them straight to the batteries. Drilled holes through the floor. Then slid the cables through rubber grommets. Lots of dawn dish soap and they slid right through.

I went to the batteries because they are right there. I have 4 of them. I only needed 6 ft of cable. The fridge don't pull much juice. I just have a little 1500 watt inverter. Only running a mini fridge and a microwave.

Thank you for your advice. Even though I didn't follow all of it. I used the same fuse link you did. It mounted real nice.
 

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#25 · (Edited)
Looks great! Have you load tested it yet?

Edit: What did they use when they initially crimped the terminals on? If crimped terminals are done correctly (using a hydraulic crimper like the one I linked in the OP), there's no freaking way they're coming off.
 
#26 ·
I honestly don't know what he used. I was short one solder on end and they didn't carry them so I asked him to crimp on a couple because I don't have the proper tool for that. He rang up my ticket and went into the back room. I heard some pounding and pretty soon he came out with my cable. Apparently they don't have the proper tool either. I ended up finding enough solder on ends to finish the job.

As for testing, I turned on everything I'm going to be using and it seemed to work fine. I have a space heater that will max out the system. I haven't tried it after the install. I did try it as a bench test before I even started. 1500 watt ceramic heater worked just fine. Put out plenty of heat but I only ran it for a few minutes. I want to start up the truck and let a heater run for an hour or so while watching and see what happens. I will probably never pull that much juice at one time in real world application. Just the mini fridge and occasionally the microwave wave to heat up a hot dog or 2. I am taking it to a electrician friend of mine next week to help me wire up the generator. Run some outlets and a 30 amp camper plug off it. I am going to have him test it for me also. Just to make sure it s putting out what it should.
 
#29 ·
Inverter install

First I would like to thank you for such an informative write up. I followed you install to the tee! I installed a 3000/6000 Tech-on pure sine wave inverter under the driver side rear seat. I ran the 4/00 cable in the exact same route. I even removed the right front inner wheel well to get the cable in the engine compartment. I tied the alternators together. The Tech-on inverter also has a hard wire connection for the 110 volt side. I took the 110 volt and ran it through a two outlet GFI and under the bottom of the truck to the left rear frame rail by the bumper. Hubbel makes a very nice water proof plastic electrical outlet enclosure (30 AMP 120V twist lock) that I mounted to the frame rail with Tapcons and fender washers. I pull a 24' enclosed race car trailer. Inside is a small air compressor, refrigerator, Dish TV, coffee pot, 15000 BTU A/C plus lights and other small electrical devices. I made a 110V twist lock pigtail from an oven/range cord to go from the trailer wip to the outlet under the truck. To my delight the inverter powers it all! Thanks again for a great how to with pictures and all!
 
#31 ·
First I would like to thank you for such an informative write up. I followed you install to the tee! I installed a 3000/6000 Tech-on pure sine wave inverter under the driver side rear seat. I ran the 4/00 cable in the exact same route. I even removed the right front inner wheel well to get the cable in the engine compartment. I tied the alternators together. The Tech-on inverter also has a hard wire connection for the 110 volt side. I took the 110 volt and ran it through a two outlet GFI and under the bottom of the truck to the left rear frame rail by the bumper. Hubbel makes a very nice water proof plastic electrical outlet enclosure (30 AMP 120V twist lock) that I mounted to the frame rail with Tapcons and fender washers. I pull a 24' enclosed race car trailer. Inside is a small air compressor, refrigerator, Dish TV, coffee pot, 15000 BTU A/C plus lights and other small electrical devices. I made a 110V twist lock pigtail from an oven/range cord to go from the trailer wip to the outlet under the truck. To my delight the inverter powers it all! Thanks again for a great how to with pictures and all!
Awesome! Now show us some pics!
 
#30 ·
Power Tech On is what I have in my 5th wheel. Mine is 2000/4000w pure sine. The first one I got would not run anything over 800w so after much discussion with the company, I sent it back and they replaced it free. First one was defective. Second one runs anything I want below 2000w.

We use it to run the wifes blow drier, our Sat TV, the DVR, our microwave (1550w). Love it.

Glad yours worked right off the bat. Show pics if you can.
 
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#38 ·
This one doesn't look bad: https://www.amazon.com/Xantrex-PROWatt-Inverter-Model-806-1220/dp/B002LGEMOQ

I've used an oscilloscope on my AIMS inverter and the damn thing sure looks like a sine wave. That's about all I can say.

Personally, I would just get the right inverter for the job once even if it's expensive. In all seriousness, I think my install cost about $1200 by the time it was all said and done. That includes wire (50 feet at $5.00/ft), outlet boxes, specialty tools (16-ton crimper, big-ass cable cutters, etc.), hardware (terminals, fuse block, etc.), and so forth. Not to mention the hours spent measuring, weighing the pros/cons of where to mount, making cables, installation, etc. For a project like this a few hundred dollars' difference just isn't that big of a deal if it results in better reliability or functionality.
 
#39 · (Edited)
Most trucks have a nice open space between the bed side and fender. I think that would be a good place to put an inverter but it would have to be easily removable for service because there wouldn't be much room to reach up inside there.

A few trucks have an air conditioned glove compartment that would be ideal.

You could build a platform to go between the rocker panel and the transmission tunnel in the back seat and mount the inverter on the underside of the platform but it would need circulation fans.

A bunch of older Hondas had the ECM in a panel under the passenger's feet. It worked good for the ECM but for an inverter you would need to provide air circulation.

Under the seat has a lot of potential. If your truck is like mine there is even a duct there to provide air flow. You would need to go into the heater box and arrange that hot air never went into that duct but it could be done.

As far as under the hood mounting goes, finding room and cooling would be tough. I wouldn't rule out mounting to the under side of the hood itself. The front of the cooling stack has potential except the inverter would have to be waterproof or other provisions would have to be made.

There may be space under the driver's seat portion of the cab. Airflow under the cab would be plentiful but again waterproofing might be an issue.

I wouldn't entirely rule out mounting in an overhead console setup. Running cables up the passenger A pillar and back down the C pillar would be a bit of a problem and having a sharp object near people's heads poses an accident risk but it could be done.

In short, there are a lot of options for mounting an inverter. I see no problem with using the frame as a ground for the inverter as long as the connections are well made. The battery would need an additional ground strap to carry the additional 250 - 500 amps if the inverter is allowed to run while the engine is cranking. If the inverter is isolated during startup even that wouldn't be needed. The starter uses about 400 amps so the OEM ground is good for at least that much.

Of course you could use a separate ground strap but I think that is overkill.

One of these days I'll do this. Then I will have a story to tell.

To run my house during a blackout, they happen all the time here, I need about 1 KW (surge to 2 KW)for the well, .5 KW for the furnace blower, 1 KW for the freezer and fridge, 1.5 KW for the range, .5 KW for the lights (all LEDs) and maybe 1 KW for everything else. So 5.5 KW for just about everything in the house at once. Probably 5 KW would handle it. I have just justified getting what I want but really I just want it without justification.
 
#41 ·
It's all plumbed. Just waiting for the not so old electric range to quit. We have had a gas range before and it was nice.

We switched from an electric furnace to a gas furnace and our electric bill went down $250/mo. on average while the gas bill went up $40/mo. in the winter. Still Idaho Plunder and Loot sends me letters every couple of months saying I need to reduce my power usage. They want to sell Idaho power to California for three times the price.
 
#42 ·
This past week I repositioned the auxiliary outlets and inlet in order to accommodate an in-bed auxiliary fuel tank. I had to re-route the cables from the inverter in order to get the receptacles all the way to the back of the bed. Some pics below.

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#43 ·
That is a nice install and well laid out.

I learn something from every install that I look at.

If you ever want to get rid of that romex section in the outlet box, what I do is crimp ring terminals onto the stranded wire and screw them down directly to the plug. Since you have a dual outlet, this would be slightly trickier.
 
#44 ·
Just curious - did you see any indication of an ACR, battery A / B switch, or any other kind of active separation of the two alternators from the battery (s) ?

It would be interesting to put a clamp meter on the system and watch current flow.

On many vehicles, the alternators at idle / high idle are only able to produce a modest fraction (20 - 30%) of nameplate rating.

These trucks seem to have a fairly sophisticated system for managing idle rpm, but it is possible under high loads that some of those amps might be coming from the starter battery.
 
#46 ·
Just curious - did you see any indication of an ACR, battery A / B switch, or any other kind of active separation of the two alternators from the battery (s) ?

It would be interesting to put a clamp meter on the system and watch current flow.

On many vehicles, the alternators at idle / high idle are only able to produce a modest fraction (20 - 30%) of nameplate rating.

These trucks seem to have a fairly sophisticated system for managing idle rpm, but it is possible under high loads that some of those amps might be coming from the starter battery.
Sorry for not seeing this earlier.

Firstly, there is no separation/isolation/switching with regard to the batteries/alternators. They are all in parallel and act as one big system. I've been running my truck with the alternators bonded together for well over a year and over 20k+ miles without so much as a peep. Inverter output is just as strong as when I first installed it; it easily sustains the rated 3kw. By accident I once drew 4.3 kw and it was humming along nicely until the 300A fuse blew; that was annoying.

Secondly, at idle, you're right that it can't sustain a continuous 3kw draw from the inverter. But modern cars' and trucks' charging systems are smart enough to detect a voltage drop and will compensate accordingly. I tested this on my truck by powering two 1500-watt space heaters from the inverter simultaneously with the truck at idle. I measured the voltage across the inverter and watched it slowly drop, and once it got down to 12.5V or so the engine automatically increased its idle speed, at which point it went back up to around 13.5V.

Basically, the truck is smart enough to deal with this. If you're really concerned you could use the high-idle functionality.
 
#47 ·
Update. It appears a loose connection developed on the input side of my fuse block which caused resistive heating and a complete meltdown of the plastic base.

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At the bottom of the above photo you can see the plastic base and it actually looks as if the stud on the right side (which would have been the input side) heated up so much that it basically liquefied the plastic and the weight of the cable pulled it down, eventually dislodging it completely from the base. With that end flapping around and the heat conducting through the fuse (which never blew because it doesn't seem like there was an actual short, and certainly not downstream of the fuse in any case -- the intact fuse can be seen just above the plastic base in the pic) the stud on the output side of the block eventually broke free as well.

Yesterday the temperature never got above 30F so I pulled the front of the truck into the garage and cranked up a space heater and got to work. Start to finish on the rehab was about six hours. The improved install has cable anchors on both sides of the fuse block (good thing I have ANL fuse blocks laying around because I had no idea there was a problem with this until I popped the hood to check the coolant tank and was greeted with this misery). The anchors and fuse block are secured to the truck with VHB tape and screws. The new fuse block has lock washers over the flat washers; I don't think the old one had lock washers which may have contributed to the loose connection that caused the heating.

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Additionally, I found that some of the insulation on the factory alternator connection had worn away, causing an intermittent short circuit. See below.

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I taped up the terminal and modified the connections I made to the alternators to make sure that they bend up and away adequately so as not to come into contact with the factory cables.

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Lastly, the white/translucent zip-ties I used inside the engine bay had become totally brittle and shattered into a thousand pieces when I started the teardown. I think these black ones are more resistant; time will tell.

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On a potentially blasphemous note I'm wondering if an install like this actually needs a fuse at all. Sounds crazy, right? Hear me out. 4/0 is not going to experience dangerous heating even up to 500A or so. Of course, the short-circuit current in a car battery is probably on the order of thousands of amps (and our trucks have two of them, so double it). But realistically, a short-to-ground is going to have significant resistance because it will probably occur when insulation on the cable wears away and some of the conductor comes into contact with a painted or dirty piece of the frame or body work; this will likely cause a short circuit but it will have relatively high resistance (and will probably be intermittent rather than continuous) such that it's not likely to result in a 300A fuse (which is the size I used for this install) being blown. When you figure that all the connections between the body work, frame, and batteries will also have some resistance, it seems unlikely that any reasonably likely short-to-ground scenario would result in a 300A current. Then again, I'm not about to test that hypothesis. ;)

Anyway, if the above logic is sound, then the fuse block is actually just adding another potential failure point. The loose connection meltdown described above would never have occurred without the fuse block. The only real issue is that while the inverter is connected to the alternators with 4/0, the alternator-battery connection is 2 AWG or something, which doesn't have nearly the same ampacity and could potentially experience dangerous heating in a short-to-ground scenario. If I was going to do this install without a fuse I'd replace those 2 AWG battery connections with at least 2/0 to each battery.
 
#57 ·
Anyway, if the above logic is sound, then the fuse block is actually just adding another potential failure point. The loose connection meltdown described above would never have occurred without the fuse block. The only real issue is that while the inverter is connected to the alternators with 4/0, the alternator-battery connection is 2 AWG or something, which doesn't have nearly the same ampacity and could potentially experience dangerous heating in a short-to-ground scenario. If I was going to do this install without a fuse I'd replace those 2 AWG battery connections with at least 2/0 to each battery.
Two words: Fusible Link