Connecting 400W 12-230V Inverter: Fuse Size (33.3A), Cable Thickness for 400W & 100W Loads

Hello.

I am going to connect a 230V converter with a capacity of 400W to the cigarette lighter socket (12V).

(If I'm not mistaken then):
If I load it like that, then the 400W to 230V will give ~ 1.7A

And now the questions:

1. Will it be ~ 33.3A for DC 12V then? Do I have to put in such a fuse?
2. What thickness should the cores of the cable supplying this current to the inverter be when the load is 400W?
3. What thickness should the cores of the cable supplying this current to the converter be when it is loaded with 100W? 4x thinner enough?

1) That is 40A or more. Because the momentary jumps on the converter probably 600-800W can be (unless you have already given the temporary ones, not the long constants).
2) 2.5mm2 is enough for me - for this, of course, a solid cigarette lighter socket because it is very important because otherwise it will heat up a lot.
3) This point is nonsensical - you either install them in reserve or not at all. Unless you are asking for some other reason?

You will actually use up to 400W or only max 100W? What will you connect to it?

Thanks for the answer.

Ad1. These 400W are its continuous capacity, the jump is 650W.
Ad2. I did not replace the socket, the original fuse is 15A, i.e. up to 180W, I can probably connect it safely without replacing the socket.
Ad3. I am going to connect to 90W at the peak, but I also wanted to know how thick (not handy, stiff and heavy) would be needed if I ever wanted to use its full 400W.

So what lived for 100W? How is it calculated?

Buy yourself a 12V laptop power supply and do not combine it with an inverter, because I suspect you need it for that. The factory installation of the lighter (provided that it is of good quality and was not used as a lighter) will withstand up to 150W at 12W, which is about 100-120W at the inverter output.

http://lumier.pl/kalkulator/

Yes, it is supposed to be for a laptop, but I already have an inverter, and all laptop car adapters that I meet either do not have a Lenovo tip (rectangular) or are very expensive.

Thanks for the link.

You could buy an older Lenovo and buy a square adapter.
Yes, I have it at home.
And you bought the converter, the power supply has only 90W, so with a power reserve of 200W, it would be enough, and on 1.0 mm2 cables it would pull without any problems.

I bought an inverter a long time ago (before I had a laptop), so I decided to use it instead of buying an additional power supply. I did not only have a wire that supplies it with electricity from the cigarette lighter socket (because the set included cables with battery clips) and hence my question.

tbik wrote:

the original fuse is 15A, i.e. up to 180W, I can probably connect it safely without replacing the socket

You're wrong. First of all - the fuse is selected with some margin - it can be assumed that about 20-30%. It cannot be assumed that the fuse current value is equal to the maximum useful current in the circuit. Second: there are usually other receivers on the fuse that also consume electricity. Although the principles of constructing such circuits aim at connecting devices on the same fuse that are not likely to be used together (or there is no more than one device with continuous power consumption connected to one fuse), in the given case it can be almost certain that the circuit current will be exceeded. Third - be aware of the nature of the lighter's operation - it is a temporary consumption, allowing a certain degree of higher current. The same current consumed continuously may damage the installation even though it will not blow the fuse (!).
At this point, it's time for a small parable: A tire compressor was plugged into the cigarette lighter socket (the same hand-made, slightly larger than the market ones, but the fuse did not blow), which was in constant use for about 10 minutes. The operation was interrupted (fortunately!) By a smoke coming out of the cigarette lighter socket. This symptom can be ignored, because it is not difficult to make a poor contact in a tarnished lighter socket. When checking the socket, it turned out that the insulation of the cable leading to the socket had melted. The fuse is still intact, with its original value!
So now consider why the inverter comes with battery grips. What was the problem with installing a much more convenient cigarette lighter plug?

Thanks for the warning and information. I will definitely use it.

As for "What was the problem with installing a much more convenient cigarette lighter plug?" in my opinion it was easier (and probably cheaper) to put on a (large, comfortable) frog than a small (and probably more expensive) lighter plug.

Generally, it would be appropriate to pull the installation with a modular connector and a 40A fuse directly next to the battery under the inverter. 4-6mm ^ 2 cable (10-12AWG). The cigarette lighter socket is a very insecure connector that likes to get hot. Especially if the socket was used for the cigarette lighter.

tzok wrote:

Buy yourself a 12V laptop power supply and do not combine it with an inverter, because I suspect you need it for that. The factory installation of the lighter (provided that it is of good quality and was not used as a lighter) will withstand up to 150W at 12W, which is about 100-120W at the inverter output.

Show such a power supply but of certain quality? Besides, where would it get power if not from a lighter with such a power supply?

It is better to use the original power supply through converters than to buy some pseudo 12V power supply, i.e. in fact converters, only it is not known what quality.

If you were to actually use non-stop, you pull the wires inside, but you make a special socket for which you connect converters because in fact, the quality of lighters is not special, although 100W or less, if good quality, will do the trick. Although a dedicated connection will certainly heat up less than through the cigarette lighter socket - you would just have to figure it out and make a 230V ala socket or something like that for 12V.

This is how it has a 14VDC to 230VAC converter, followed by a 230VAC to 19VDC power supply ... instead it would be better to use a 14VDC to 19VDC converter. Such a connection would have higher efficiency, and therefore lower power consumption from the 12V socket. Lenovo offers such power supplies, there are also many replacements. Nevertheless, it has already been explained that the author does not want it because he already has this converter.