Thread: M2 Atx .. qmm wires?

Originally Posted by GreenBeauty

I have an m2 atx power supply.
On this m2 atx there are some 1qmm wires connected.

I want to connect my carpc in the car to my car power supply
But are the 1 qmm wires thick enough to work safe?

I think 10qmm is needed to have a safe connection in my car.
What do you think?
And why is the m2 atx power supply with < 1qmm wires connected?

Never heard of "qmm" measurement for wires, so please ignore my American bullheadedness as I use AWG measurements.

The m2-atx comes with 16awg wires for the power, battery, and accessory wires. This will be fine for standard use, with short runs of wire and the wire in 'open air' (i.e. not encases in spiral wrap or similar). By 'standard use', I mean you giving about 40% overhead on the wattage you use compared to its rated max.

However, if you are going to have long wires runs (i.e. power supply in the trunk), and/or encase the wire in something, and/or use the power supply close to its rated capacity, I would use larger wires. 12awg would be a better option, or better yet 10 awg since it's generally not much more expensive then 12awg. And you can still use common electrical terminals.

If you do use a larger gauge wire, DON'T use the wires included with the m2-atx. For example, don't connect your 12awg wire to the 16awg that comes with it. Instead, connect the 12awg wire all the way to the m2-atx.

Not everyone seams to agree with me when I recommend wire gauges to use around here, although I base recommendations on common standards for wiring, so take my advice however you want =)

hehe sorry..
Here in Europe we talk in "qmm / mm2" about the thickness of wires.
My power supply is in the trunk indeed.

So I must connect an 10awg wire all the way to the m2-atx directly.
Can I just unsolder the old power wire, and solder a new 16 awg wire to the M2 ATX ?

What I don't understand is... why is the M2 ATX made with 10awg wires..
I think this is very dangerous when you use a lot of usb devices?

ps. I think an 7 awg wire is maybe more suitable compare to price

Originally Posted by GreenBeauty

hehe sorry..
Here in Europe we talk in "qmm / mm2" about the thickness of wires.
My power supply is in the trunk indeed.

Didn't know vehicles over the pond had trunks? I thought they all had boots? lol j/k

Originally Posted by GreenBeauty

So I must connect an 10awg wire all the way to the m2-atx directly.
Can I just unsolder the old power wire, and solder a new 16 awg wire to the M2 ATX ?

What I don't understand is... why is the M2 ATX made with 10awg wires..
I think this is very dangerous when you use a lot of usb devices?

I think you got your wire sizes mixed up above; or the awg has you confused because it's so backwards. 10awg is thicker then 16awg. The wires that come with the m2-atx are 16awg. Let's see if I can simplify everything in one shot (so please excuse any repetition)...

Connect one end of a 10 or 12 awg wire to the battery, and run this wire to the boot where the m2-atx is. Then, crimp/solder on a female quick disconnect on the other end and plug this into the appropriate terminal on the m2-atx. IF, as it sounds above, you have soldered wires directly to the m2-atx terminals -- that is fine as well, just unsolder the original wire and replace it with you thicker wire.

Most likely 16awg is used by the manufacturer of the m2-atx for cost reason, as well someone probably did a study and balanced the cost with what size wire would be fine for most "average" uses of these power supplies. You are perfectly fine using 16awg wire, just with the caveats I first mentioned.

ps. I think an 7 awg wire is maybe more suitable compare to price

It might be in the UK, I'm not sure what is considered "common" sizes over there. Here in the US 10/12awg is not that much different in price, yet the jump to 8awg (the next thicker size) is almost double the price.

Ok I get it..
Maybe a stupiq question.. but how do you solder the wires in this connector?

Originally Posted by GreenBeauty

Ok I get it..
Maybe a stupiq question.. but how do you solder the wires in this connector?
[IMG]

Ah ha.. I didn't think you had the wires soldered to the terminals. For the red, white, and black wires provided in the m2-atx kit, they have crimp connectors on the end.

For your new wires, it's best to use the same crimp connectors. They will slide onto the three pins in the upper left part of your picture). You won't be able to reuse the ones that come with the m2-atx, as they are machine crimped on and don't come off easily.

In the US the ones you would need to buy are called "Fully insulated Female Quick Disconnects", or also "Fully insulated FQD". Maplin has them here (in packs of 10), though I'm you can find them other places I just don't know where in the UK. Yellow is for 10-12awg wire (what I recommend), blue is for 14-16awg (what the m2-atx comes with).

You COULD solder directly to the terminals on the board, but will take patience and steady hand (different metals will make it tougher, and you have a small space to work in). Solder the middle one first carefully, then solder on the outside of the top and bottom ones.

ok, just to clarify. 1qmm/1mm2 is 1 cubic millimetre/1millimetre square we use mm to measure cable sizes in UK.
although AWG sizes seem to be the same as our sizes for wiring car audio for example, i have 4 gauge cable running to my amplifier (4AWG)

i think this is correct