12 volt 2000 watt inverter charger recommendations

[Sunking]

Yeah they mention in the manual "may not meet all NEC or local codes" and I thought that was odd they were even pointing it out but still giving you those numbers.

That is put there by the lawyers so you cannot sue them because you Joe Consumer are ignorant. Consumers are not smart enough to read between the lines and see the RED FLAG warning; "may not meet all NEC or local codes" is one heck of an understatement. If you knoew what it really takes would quickly realize the terminals are not big enough and nothing is designed to do what it claims. Kind of hard to sell a POS if you admit it it s POS and dangerous.

[gbynum]

Yeah they mention in the manual "may not meet all NEC or local codes" and I thought that was odd they were even pointing it out but still giving you those numbers.

And as SK and others have pointed out, the "NEC or local codes" are to protect the wire. Voltage drop at 120 or 240 Volt (absolute which is what heats wire) is a far lower % than at 12 Volt. You need to be more conservative with lower voltage systems, not less.

[somekevinguy]

Terminating the wires. And stripping them with out using a knife and cutting critical strands. I have thermal strippers that melt the insulation away. They stink a lot, but never nicks the wire.

Oh OK. I've had all the stuff to terminate wires up to 4/O for 30 years but maybe I'm not your average consumer.

[Mike90250]

.......Why do you say a consumer is already pushing it working with 4 awg? Is because of terminating wire that size or another reason?

Terminating the wires. And stripping them with out using a knife and cutting critical strands. I have thermal strippers that melt the insulation away. They stink a lot, but never nicks the wire.

[somekevinguy]

The wire insulation rating is part of what determines the amount of amps it can handle. When you run more than 3 wires in an enclosed raceway (pipe, conduit, trough) you have to lower (or de-rate) the amps rating. Some wire insulation is only good in dry conditions other is rated for dry or wet.

If you can cool the wire in open air it can withstand higher amps then it is rated at, for brief periods. Then it gets hot and can melt the terminations or insulation.

Some manufacturers state you can run a lot more amps through a wire then it is intended because they think it will be for only a short time and they aren't held to meeting NEC standards just their companies insurance limitations.

Yeah they mention in the manual "may not meet all NEC or local codes" and I thought that was odd they were even pointing it out but still giving you those numbers.

[SunEagle]

Yeah like I said Magnum is specing 4/0 with a 400 amp fuse and 2/0 with a 300 amp fuse which I know doesn't agree with NEC. I thought they were one of the more reputable companies. I'm wondering why they do this? Do the NEC charts just assume longer runs than these super short runs of 5 feet or does run length not even matter for thermal limits and then you have to go even even bigger from there for voltage drop based on run length?

The wire insulation rating is part of what determines the amount of amps it can handle. When you run more than 3 wires in an enclosed raceway (pipe, conduit, trough) you have to lower (or de-rate) the amps rating. Some wire insulation is only good in dry conditions other is rated for dry or wet.

If you can cool the wire in open air it can withstand higher amps then it is rated at, for brief periods. Then it gets hot and can melt the terminations or insulation.

Some manufacturers state you can run a lot more amps through a wire then it is intended because they think it will be for only a short time and they aren't held to meeting NEC standards just their companies insurance limitations.

[somekevinguy]

The problem is the load may be much lower then the amperage a 4 awg can handle for most of the time and higher a very short period of time. That allows the 4 awg to work but it will get hot. But with an inverter that can accept a much higher load for a longer time and then the amps will increase and can exceed the 4 awg rating by a lot.

When you design your wire size you need to consider the highest amps it may see and then protect it with the proper fusing. If you don't use a wire big enough to handle the amps going through it then the wire gets real hot and burns up.

Yeah like I said Magnum is specing 4/0 with a 400 amp fuse and 2/0 with a 300 amp fuse which I know doesn't agree with NEC. I thought they were one of the more reputable companies. I'm wondering why they do this? Do the NEC charts just assume longer runs than these super short runs of 5 feet or does run length not even matter for thermal limits and then you have to go even even bigger from there for voltage drop based on run length?

[SunEagle]

A wire manufacturer told me 1/0 was good for 300 amps on their website but I thought that was pretty ridiculous myself and I don't even know anything.

Magnum only specs 2/0 wire for 300 amps and 4/0 for 400 amp in free air less than 5 feet in their manuals. Is Magnum full of chit? I thought they were a reputable manufacturer.

Why do you say a consumer is already pushing it working with 4 awg? Is because of terminating wire that size or another reason?

The problem is the load may be much lower then the amperage a 4 awg can handle for most of the time and higher a very short period of time. That allows the 4 awg to work but it will get hot. But with an inverter that can accept a much higher load for a longer time and then the amps will increase and can exceed the 4 awg rating by a lot.

When you design your wire size you need to consider the highest amps it may see and then protect it with the proper fusing. If you don't use a wire big enough to handle the amps going through it then the wire gets real hot and burns up.

[somekevinguy]

BS half truth. NEC and all electrical codes have minimum wire gauge standards vs current. Example a 50 amp circuit requires a minimum 6 AWG wire. You cannot use anything smaller. At 100 requires a minimum 4 AWG, and at 200 amps require 2/0. Whoever told you 1/0 is good for 300 amps is full of chit and should be ignored and shot. 300 amps requires 4/0 AWG.

A wire manufacturer told me 1/0 was good for 300 amps on their website but I thought that was pretty ridiculous myself and I don't even know anything.

Magnum only specs 2/0 wire for 300 amps and 4/0 for 400 amp in free air less than 5 feet in their manuals. Is Magnum full of chit? I thought they were a reputable manufacturer.

Why do you say a consumer is already pushing it working with 4 awg? Is because of terminating wire that size or another reason?

[littleharbor]

That would depend on what stranding is used. Example a 4/0 Class A stranding would require a cheater bar and a gorrilla from the zoo contracted to bend and form. Class H Super Flex a high school girly boy can work with it.

I dismantled a system that had, I'd guess 1/0 19 strand cable going to the batteries. I thought that was really stiff and that pre-bending it before making the connections would be a real b***h, but absolutely necessary to get the lugs properly oriented.

[Sunking]

How difficult is it to bend cable that large when making your connections?

That would depend on what stranding is used. Example a 4/0 Class A stranding would require a cheater bar and a gorrilla from the zoo contracted to bend and form. Class H Super Flex a high school girly boy can work with it.

[Sunking]

In vans and RVs a lot of people are doing like 2 or 3 foot round trip runs though so you can get away with smaller wire.

BS half truth. NEC and all electrical codes have minimum wire gauge standards vs current. Example a 50 amp circuit requires a minimum 6 AWG wire. You cannot use anything smaller. At 100 requires a minimum 4 AWG, and at 200 amps require 2/0. Whoever told you 1/0 is good for 300 amps is full of chit and should be ignored and shot. 300 amps requires 4/0 AWG.

[Sunking]

If its unsafe, why are these companies selling these products? Thx.

Because they can. You can buy ganja, tobacco, beer, alcohol, cars, motorcycles, and the number 1 killer of kids and young adults is cell phones. It is none of those companies job to educate the public.

The real issue is current. The general public is taught high voltage is what makes electricity dangerous which is true, but only 1/4 the whole picture. However high voltage is not defined in public terms, but anything less than 600 volts is Low Voltage. It is super easy to protect the public from voltages, all it takes is Insulation, Barriers, and Distance. Roughly 1-inch for every 1000 volts.

Power or Watts is the heat portion of electricity. and Ohm's Law defines POWER = VOLTAGE x CURRENT. So 100 watts of power can be delivered with 100 volts @ 1 Amp, or 1 Volt @ 100 Amps. On paper and theory, either way works. However in practice it does not quite work that way. Rather at 100 volts or 1 volt the Insulation does not change, but the cross-sectional size of the conductor changes by a factor of 100. At 1-Amp with 100 volts pushing it only requires a 30 AWG wire not much larger than a strand of hair, at 100 amps the size of your thumb. At 500 Amps the size of your wrist.

So why is high current dangerous? Well so far I have covered 3/4 of electrical elements of Power, Voltage, and Current. There is another element called Resistance, and every conductors (wire), connection, and semi-conductors have resistance and is what is used to control electricity. FWIW an Insulators has extremely high resistance, most up to Infinity up to a point. Air is an insulator. As I stated POWER = VOLTAGE x RESISTANCE, but Ohm's LAW states VOLTAGE = CURRENT x RESISTANCE, that would means then POWER = CURRENT x CURRENT x RESISTANCE. A good example you may have noticed is when you run a high power gizmo like a blow dryer, toaster, vacuum cleaner, too many Xmas lights, the cords get hot especially where the PLUG is plugged into a wall socket. That connection has higher resistance than the wire does. That 1500 watt Blower Dryer operating @ 120 volts only pulls 12.5 amps, and with a loose connection can get hot enough to burn you.

So here is the deal to handle 500 amps at low voltage requires a very large conductor, a minimum 750 MCM which is the size of your wrist and requires a lot of surface area between connection points maintaining a thousand pounds of pressure. That is why the Terminal above is so large with 2 x 5/8" bolt holes that require 40-foot pounds of torque. That terminal also require some very expensive tooling, a 14 to 16 Ton Hydraulic Press, training, and experience to install the terminal correctly to keep the connection resistance low. No way a DIY can do it. Now look at the terminals on that Inverter. It is not made to handle that kind of hardware or the weigh and stress a 750 MCM cable that weighs 7 pounds per foot.

About a large of a cable a Consumer can work with is 4 AWg and that is still pushing it and asking for trouble. A 4 AWG can only safely handle 100 amps at most for a very short distance up to 10 feet @ 12 volts. That would be 1000 watts max @ 12 volts, 2000 watts @ 24 volts, and 4000 watts @ 48 volts.

Now you know why utilities use such high voltage up to 1,000,000 volts and with only 100 amps is 100,000,000 watts of power, enough for a small city.

[somekevinguy]

In vans and RVs a lot of people are doing like 2 or 3 foot round trip runs though so you can get away with smaller wire. Magnum only recommends 2/0 for their 2000 watt up to 5 feet and I've seen wire manufacturers say you are good with 1/0 for 300 amps. I don't know anything though. That's just what manufactures and everyone else besides this forum says so it's probably all lies from millennials and hippies and stuff.

[littleharbor]

Yes. I think you got it. The cables on my inverter are a fair amount larger than 4/0 which reduces the loss in the wires

How difficult is it to bend cable that large when making your connections?