Polarity of 12 Volt Plugs and Sockets

Well I may get some argument here, but the way you suggested is correct. The way I was taught many years back was if you look at the pins from the front then draw a line up from the vertical pin through the horizontal pin you get a cross or positive sign. However I have seen a few wired opposite to that. As long as yours is both wired the same you will be right.

There are two possible ways you can wire up a 2 pin connector - and that why there a two "standards" for polarity of the T connector.

A very good reason to avoid the T connector and use the Anderson Connectors. The Grey connectors have polarity moulded into the body and the Red/Black Powerpoles have obvious polarity.

roll me in pig fat and poke me with a stick, but there is a standard in Australia for 240v AC sockets and its a three pin setup. Doesn't your shaver have one of them on the end of its lead?

In the three pin case the top lefthand is the active and righthand is the neutral and the bottom vertical pin is the earth.

I have the two pin Horiz / vertical plugs installed in my vehicle but for 12v only and wired as you suggested.

Have pulled apart some 12v and also a 240v plugs and sockets for a look to see if there are (+) and (-) marks in there for reference points.
There was no reference points for (+) and (-) wires on either sets, however there was a reference point for the 'green' wire on the two 240v plugs.
That's not to suggest it's not written in an obscure 'book' somewhere?

Mainey . . .

I've always gone with...

hold the plug so that it makes a "T"

Positive is bigger then negative, therefore positive on top.


This is how all my gear is done, but I have found that some people do it the other way.


cheers

Dave

Mike is right in saying use Anderson Plugs or Power Poles they are genderless and are easy to identify for positive and negative and you can now get a Chassis mount flush fitting that takes two sets of either 15A 30A or 45A Power Poles that can replace Cig sockets in vehicles.
There is also a 30A distribution panel that takes power in and gives 4x fused outlets plus a double USB outlet.
Ian

G/day PiSA,I don`t mean to throw a spanner in but,most 240/12 Transformers in c/vans have a 2 pin on the 12v end and the positive pole is the Vertical pin ,don`t know about inverters, Maybe with transformers it`s an unwritten rule but all the vans i`ve had have been vertical positive for 12volt .Hope this helps.

Regards,

Hi Peter

I would recommend using Anderson plugs as suggested. I don't know what size your inverter is but it may require heavier cable than the ELV socket / plug you are using can take.

Make sure to increase your cable size to combat voltage drop over distance otherwise your inverter may go into low voltage protection half way through your shave.

Regards

Derek from ABR

This post is about the "Polarity of 12 Volt Plugs and Sockets"

Peter needs to run his 240 volt shaver from an inverter.
He has bought the SOCKET to wire *into the battery* and the PLUG to wire *into the Inverter* this is a 12v (nominal) cable not 240 Volt.

Peter is asking about connecting the earth (neg) cable to the Vertical pin on the Plug/socket and the positive (pos) to the Horizontal pin.
As I read the post these are 2 x single cable connections, with the (+) to (+) and (-) to (-) at each end of each individual cable, they will NOT interchange current with each other as they are individual cables, just like an 'extension' cable is.

As I read it, it's not relevant to 240 Volt connections because the cable is 12 Volt (nominal) between the Battery and the Inverter!

The lead out of the Inverter is definitely 240v and a conventional 240v power board can be plugged in to the Inverter 240v outlet socket to supply power to the shaver and various other 240v accessories. Image Could Not Be FoundMainey . . .