What gauge wire from batteries to inverter

[opnspaces]

I am going to install an inverter in my trailer and am curious about what gauge wire I need to run from the batteries. To be honest I really don't have an application or device I want to run off it. I just want to do it for the "because I can" factor. I plan to mount the inverter against the front wall of the trailer so I don't imagine more that ten feet of DC wiring from batteries to inverter. Below is what I have to work with since I already own them.

A Zamp 2000 watt pure sine model ZP-2000ps. What gauge wire would I need to get optimal use from this? (Figure 10 feet from battery to inverter). This is the one I'll probably use as this is what I had in mind when I bought it.

or

a Zamp 600 watt pure sine model ZP-600ps. What gauge wire would I need if I decided to install this model instead. (Figure 10 feet from battery to inverter).



Is voltage drop a concern in this kind of setup, or is that mostly a concern with solar installs?

Thanks

[SoundGuy]

GordonThree wrote:
If you're just building the system and haven't bought anything yet. Go for higher voltage. 8x golf cart batteries (or a lithium pack) gets you a nice 48v system. This lets you use lighter cable, and everything else is much more efficient. An inexpensive DC-DC converter provides 12v for small loads like pump, lights, etc.

The OP said in his opening post - "I am going to install an inverter in my trailer and am curious about what gauge wire I need to run from the batteries. To be honest I really don't have an application or device I want to run off it. I just want to do it for the "because I can" factor." Now you want him to jump to EIGHT GC-2s or even lithium packs?!! Good grief. :R

[Bill_Satellite]

opnspaces wrote:
I am going to install an inverter in my trailer and am curious about what gauge wire I need to run from the batteries. To be honest I really don't have an application or device I want to run off it. I just want to do it for the "because I can" factor. I plan to mount the inverter against the front wall of the trailer so I don't imagine more that ten feet of DC wiring from batteries to inverter. Below is what I have to work with since I already own them.

A Zamp 2000 watt pure sine model ZP-2000ps. What gauge wire would I need to get optimal use from this? (Figure 10 feet from battery to inverter). This is the one I'll probably use as this is what I had in mind when I bought it.

or

a Zamp 600 watt pure sine model ZP-600ps. What gauge wire would I need if I decided to install this model instead. (Figure 10 feet from battery to inverter).



Is voltage drop a concern in this kind of setup, or is that mostly a concern with solar installs?

Thanks

Use #2 wire (yes, big fat cable) and you will be glad you did. Many places can make a cable of any length with whichever type end connector you need.

[BFL13]

I have my inverter, converter, and solar controller all snuggled up to the two AGMs inside the rig under the sink area. IMO it is ok with AGMs (true or not--I am doing it and that's that! 🙂 )

The inverter needs to be handy to where I can swap between having the shore power cable into the inverter and shore power cable out to a pedestal or portable gen. The converter does not get plugged into anything when the shore power cable is plugged into the inverter.

The inverter has two each pos and neg terminals. 3 foot #4 cables for all, across the two 100AH AGMs balanced. I have zero issues with running the microwave for several minutes at a time a few times a day.

It was also easy in the 5er to get the inverter close to its batteries. If I had a TT, I would be looking at AGMs so I could keep them inside like I do with the Class C, which would allow the inverter to have a short wire run to the batts inside the TT.

[GordonThree]

Even if someone was giving me 10 gauge wire for free, I'd thank them for their contribution and still buy some 4/0 welding cable.

Do it right the first time, welding cable isn't very expensive.

There's no penalty for using heavier cable than necessary. And when it comes time to run a large load, heavier cable means less drop, which means your inverter isn't working quite as hard. Turning 13v into 120v is easier than 11v into 120v.

2oldman's suggestion is SPOT ON. If you're just building the system and haven't bought anything yet. Go for higher voltage. 8x golf cart batteries (or a lithium pack) gets you a nice 48v system. This lets you use lighter cable, and everything else is much more efficient. An inexpensive DC-DC converter provides 12v for small loads like pump, lights, etc.

[pianotuna]

opnspaces,

Zamp is pricey compared to some other inverters. Unless you have it already I'd suggest something else.

The inverter needs to be as close as humanly possible to the battery bank without being in the same compartment.

My wire run is about four feet--and that is LONG for a 3k unit.

[3_tons]

GordonThree wrote:
10 feet is 5 feet too many for a 2000 watt in my humble opinion. Remember round trip, whatever your wire length is, double it, since you have a positive and negative wire, and the electricity flows through both. Voltage drop is a very real concern especially under heavy load.

For my 2800 watt 4000 watt surge inverter I used 4-ought #0000 welding cable, 12 feet total round trip which includes 6 feet for the cable linking four batteries in parallel.

Keep your DC cables very short and use an extension cord at the output to get AC where you need it.

X 2

[MEXICOWANDERER]

Here's a real world tip about voltage drop influence...

Coffeemaker 950 watts

24 oz brew 55F water

At 120vac one minute fifteen seconds

At 100vac two minutes thirty (five?) seconds

Microwave. 8oz russet potato

Seven minutes

Eleven and a half minutes


" Need 4x #10 to make #4 "
Double wire drop three sizes 2x10 9-8-7 (seven gauge)
Works with AWG. SAE wire gauge doesn't cut it...

[GordonThree]

10 gauge is speaker wire, not suitable for an inverter. Where did 10 gauge come from?

Why is the inverter being installed so far from the batteries?

[time2roll]

If the tag says 13 amps load you can count on close to 130 amps from the 12 volt battery. (amps x10)
Best to stay away from parallel wires unless the inverter has dual input terminals. Get the right stuff. I posted a link above.

As far as equivalent wire you need to convert to circular mils to add the cross section of copper. But again try to stay away from parallel.
Cross section area is on this ampacity chart:
http://www.genuinedealz.com/voltage-drop-calculator
Need 4x #10 to make #4

[SoundGuy]

opnspaces wrote:
wow, thanks for the education everyone and thanks Soundguy for the chart. It looks like I better figure out realistically how long my run will be so I can if I really want to do this and how much it will cost.

Soundguy said he doesn't pull more than 70A. What would cause that kind of load?

We normally camp on electric sites but I installed an inverter for those times we may lose shore power. In those cases I can still power our toaster which draws a measured 696 watts or our coffee maker which draws 505 watts. At a nominal 12 volts that's ~ 58 amps & ~ 42 amps respectively. The question though in your case is, aside from heavy wiring necessary to make the most of a 2000 watt inverter what do you intend to use to power the inverter, 'cause a single battery sure isn't going to do it? :h

[opnspaces]

wow, thanks for the education everyone and thanks Soundguy for the chart. It looks like I better figure out realistically how long my run will be so I can if I really want to do this and how much it will cost. Based on the replies I have a few more questions if you don't mind.

Soundguy said he doesn't pull more than 70A. What would cause that kind of load? I can't imagine anything in my trailer that would pull a large load except maybe the microwave. How do I figure out the draw from it. Do I divide 120/4=30A?
The tag says 120V A.C 60Hz 13.0A single phase
Power Consumption 1.5KW
Maximum Output 1000W*, Water load 275ML
Normal operating voltage 4.0KV

Are two 10 gauge wires in series the same as one 5 gauge? Or is it more like the same as a 7 gauge because of losses?

[SoundGuy]

opnspaces wrote:
A Zamp 2000 watt pure sine model ZP-2000ps. What gauge wire would I need to get optimal use from this? (Figure 10 feet from battery to inverter).

By optimal use I'm guessing you actually mean "maximum" - if so, a 2000 watt 12 vdc input inverter would pull ~ 167 amps at full load. :E If you're "guessing" 10' from the battery to the inverter that means a 20' run so this chart tells us to carry that load over that length of cable you would need to use at least really heavy 0 AWG cable, better still 2/0 AWB. You really want to do this when you have no specific need in mind? 🙂



Case in point - I mounted a 1000 watt PSW inverter in my trailer's front pass through storage compartment and have 6' of 4 gauge running out to the tongue mounted battery. For full load this isn't heavy enough wire gauge but the most I ever pull at any given time with this inverter is no more than 70 amps. You might consider what you really intend to use this inverter for, then wire it for that application.

Some use an inverter "whole house", meaning the inverter's output feeds the entire trailer, either via a transfer switch or simply by plugging the trailer's main service cable into it. I did that myself initially but later wired in dedicated duplex receptacles in key locations inside the trailer, and one outside, so I can access the inverter output directly by simply plugging into those receptacles. Pics are in my gallery. 🙂

[GordonThree]

I'm using a 400 amp Class T fuse. They call it a catastrophic failure fuse. I went class T because I wasn't comfortable with the interruption rating for the much cheaper ANL fuse. Somewhere I calculated a catastrophic discharge of my battery bank could be beyond the interrupt rating of ANL.

My Magnum manual recommends doubled 4/0 cabling for longer runs, but they really discourage it.

[wolfe10]

Be aware that 10' from batteries to inverter is 20' of wire when you are calculating gauge needed.

Those little electrons have to make the round-trip!

[2oldman]

Some of us have gone to 24 or 48 volts to lessen line loss and use thinner, more flexible wire.

opnspaces wrote:
Is voltage drop a concern in this kind of setup, or is that mostly a concern with solar installs?

Not sure what you mean there...solar wiring is a different subject.