How to Wire a Plug
Internationally, there are around 14 different standard plug sockets used internationally, at a variety of voltages and frequencies.
In SA, officially, we have a 230V 50Hz system and have 4 standard plug types (and one discontinued one).
Type M – Standard 3 Prong
Type C – 2 Prong
Type F – Round 2 Prong (UK – Schuko)
Type N – New 3 Prong
Type D – Small 3 pin, was typically used for lights and limited to 5A.
Step 1
There may be many reasons you want to wire a plug. You could want to remove the 2 prong plug because you don’t have an adapter. Your plug may be broken. Whatever the reason, the first step is to decide what plug you are going to use.
First step in any electrical work is to always make sure that all the power sources have been isolated. In this instance that is easy as we just need to make there the plug has been removed from the wall.
Step 2
Remove the old plug. In most cases you can just snip it off with your side cutters.
Step 3
Measure and strip off the outer insulation of the cable. This can be done with either side cutters or a box knife.
Step 4
Now you can measure and trim the conductors in the cable to the correct length. The Live and Neutral (the brown and blue wires) will be the same length and the Earth wire (Green or Yellow or Yellow/Green) will be longer. In the case of the Type N all three conductors will be different lengths. Once cut to length, you can strip the ends of the conductors off to expose the care copper. You only need to strip off enough to fit into the connector in the plug.
Step 5
Now you need to make your connections. At this point it is important to connect the correct wire to the correct pin. There is an easy way to remember this:
Look at the plug from the back, so that the pins are pointing away from you in a triangle with the point at the top.
So,
Brown is Live. This can be shortened to BR, which also can mean Bottom Right. The plug will also more than likely have a mark that says “L”.
Blue is Neutral. This can be shortened to BL, which also can mean Bottom Left. The plug will also more than likely have a mark that says “N”.
Then the third wire (if there is one) is the earth. This connects to the top pin. The plug will also more than likely have a mark that says “E”.
Insert the stripped wire into the screw connector and tighten. It’s important to make sure a good connection is made. A loose connection can result in a heat building up and this can be a fire hazard. Just don’t over-tighten and damage the connection.
And that it, insert or fasten the wire into the wire holder, close up the plug, and you are done!
Congratulations, you just changed a plug!
Materials and Tools
Everything you need for this can be found in your basic toolbox. If you don't have a basic toolbox, check one out here:
https://chrisdoesstuff.co.za/the-basic-toolbox/
You will need:
A new plug to wire
A side cutter
Screwdrivers (flat and Philips)
Utility knife
Optional:
Wire stripper.
The History
You may think “Why so many different kinds of plugs?”, so first, a bit of history.
The IEC (International Electrotechnical Commission) first started trying to standardise electrical distribution systems in the 1930’s, but it wasn’t until 1986 that the first standard standard design for a round pin plug intended for use in 250V systems was published as IEC60906-1. Later, in 1992, a standard for a flat pin plug intended for use in 125V systems was published as IEC60906-2.
Discussion around a new plug standard for South Africa started back in 1993 and a new standard (the Type N) had been published in SANS 164-2 (which is the South African National Standard for Plug and Socks for use in Households and Similar Processes) by 2006.
In 2012 the new plug had been included in SANS 10142-1 (the Wiring Code). In 2016 it was announced that the new plug standard would become semi-mandatory and in January 2018 it became mandatory that any socket point in a new installation (essentially a new circuit) would need to contain at least 1 Type N. This means you don’t need to go and change all your existing sockets! The new Type N is an addition to the current standards and only required in a new installation.
To date, only 2 countries have adopted the new IEC standard. South Africa and Brazil (however Brazil still deviated from it by supplying both 230V and 127V using the same socket).
Now, you probably weren’t even aware that we have a new plug standard and likely have never seen one. I’m in the electrical industry and even I was taken by surprise when the new standard was introduced. The question must be asked: “Why? Why the change?”.
Well there are a few reasons:
The new standard is safer. This is probably the most important point. The big 3 prong plug we all know isn’t particularly safe. It’s possible to touch the metal pins while inserting and removing the plug which could lead to electrocution. There is a false sense of security in that it has a switch, but this doesn’t mean you can’t get shocked. And the large holes in the socket are big enough to be a risk to children sticking the fingers or something else into them.
The new Type N plug and socket address these issues. They are designed in such a way that you cannot come in contact with the pins while inserting and removing the plug and you can’t stick anything in the live holes as the shutters that cover the holes have to be pressed at the same time to move out the way. As a bonus, the Type C 2 pin plug also fits in a Type N socket which makes it a lot more useful as you don’t need a bunch of adapters for things like cell phones.
One other major factor in the change is cost. The new Type N plug requires only a 5th of the brass for the same or better current carrying as the old standard Type M.