{"id":5812,"date":"2023-07-15T20:12:45","date_gmt":"2023-07-15T19:12:45","guid":{"rendered":"https:\/\/www.andrewhope.co.uk\/Blog\/?p=5812"},"modified":"2026-07-21T21:19:59","modified_gmt":"2026-07-21T20:19:59","slug":"making-my-own-25-metre-single-socket-ip66-extension-cable","status":"publish","type":"post","link":"https:\/\/www.andrewhope.co.uk\/Blog\/making-my-own-25-metre-single-socket-ip66-extension-cable\/","title":{"rendered":"Making my own 25 metre single socket IP66 extension cable"},"content":{"rendered":"

My very own flexible 25M extension cable, single socket with an IP66 protection rating<\/strong><\/p>\n

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Disclaimer<\/strong>: This page contains affiliate links. Predominantly as an an eBay Partner Affiliate, Google Adsense and Amazon Affililate and as a member of other affiliate networks. If you choose to make a purchase after clicking a link, I earn from qualifying purchases and may receive a commission at no additional cost to you.<\/em><\/p>\n

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Safety Disclaimer<\/strong>: This article isn’t intended as a DIY guide, I recommend using professional services or purchasing products directly\u00a0 always rather than making yourself. I take no responsibility for any injuries that occur. I write this article merely to document the things I do for money saving, or for ideas. All devices that I use electrically will be protected by a plug in circuit breaker for extra protection<\/em><\/p>\n

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Why create one and not buy one?<\/h2>\n

Well, obviously theres no fun in just buying something, and this website is about DIY and money saving. Learning a skill means you have that skill for life. There are plenty of people who don’t even know how to wire plugs.<\/p>\n

Making my own cables, allow me to customise them. The problem with purchasing a pre-made kit, other than it being expensive, is that it doesn’t have the exact requirements I wanted. I can find a long extension which is either 50m – 4 gang, or something like 25m – 2 gang.<\/p>\n

I simply wanted a 1 gang extension. I also wanted something loose rather than on a wind up reel, as I find it easier to loop them quickly when needed. I purchased a 50 Metre reel of Electrical cable. I could make a variety of extension cables with the relevant socket housings just by cutting the able to length. I only wanted long cables for working on my car from the shed. So chopped the reel in half for two long cables to use.<\/p>\n

I “generally” have no need for using extension cables, however for the times when I want to run a cable to my car. Or having a long cable, I don’t want to be joining them together or unravelling a long reel. I’d rather have something that I can quickly grab when I need it.<\/p>\n

Does it work?<\/h2>\n

Yes, obviously. First thing I did was to plug it in and hook up a fan to make sure there was no problems.<\/p>\n

Technical Considerations when making your own extension<\/h2>\n

This isn’t really a section I’m knowlegeable about. However I understand most of the technicalities surrounding them. All cables have resistance in them, and generally if a cable is wound it has more resistance (this is why you are meant to unwind reels), otherwise it messes up their resistance and affects power carrying capacity (resistance in wire = heat). The more heat it carries the less it performs. I’m using my extension cable in a “free air” style setup, so there’s plenty of room for heat to escape.<\/p>\n

Amp rating and Voltage drop were the main factors that I had to consider when making my Electrical cable<\/p>\n

A flex cable that is 1.5mm2 in diameter across the conductors can carry a varying amount of power based on it’s fixings and the temperature of the cable. Generally speaking though, a cable this size is rated for 10A of ampacity, based on UK power that means I could power something up to 2300w in power which is fine for me. In terms of voltage drop the length of the cables I’m making (around 25m) have a voltage drop of around 30mV per meter. So I’d be losing around 7.5v in power supply over the full distance of the cable.<\/p>\n

So the realistic power is now 10A x 222.5v (2250w) which isn’t worth worrying about. As I mainly intend to use things like a Drill, Henry Hoover, and Pressure Washer (all around 1300w) at most I’m going to be using 6-7A of power which is fine for the cable exntesion that I need and it is sufficiently sized for my requirements.<\/p>\n

What are the standard wiring colours on modern cable?<\/h2>\n

There are 3 colours on Electrical cable of modern cables. In terms of wiring, there’s a simple method to remember for wiring sockets:<\/p>\n