“never plug extension cords into extension cords” is probably the most common piece of electrical related advice I’ve ever heard. But if you have, say, 2 x 2m long extension cords, and you plug one into the other, why is that considered a lot more unsafe than just using a single 4 or 5 meter cord?
Does it just boil down to that extra connection creating another opportunity for the prongs to slip out and cause a spark or short circuit? Or is there something else happening there?
For that matter - why aren’t super long extension cords (50 or more meters) considered unsafe? Does that also just come down to a matter of only having 2 connections versus 4 or more on a daisy chained cord?
Followup stupid question: is whatever causes piggybacked extension cords to be considered unsafe actually that dangerous, or is it the sort of thing that gets parroted around and misconstrued/blown out of proportion? On a scale from “smoking 20 packs of cigarettes a day” to “stubbing your toe on a really heavy piece of furniture”, how dangerous would you subjectively rate daisy chaining extension cords, assuming it was only 1 hop (2 extension cords, no more), and was kept under 5 or 10 metres?
I’m sure there’s probably somebody bashing their head against a wall at these questions, but I’m not trying to be ignorant, I’m just curious. Thank you for tolerating my stupid questions
Others have pretty much mentioned it. Too thin of conductors for the total length required which can overload the cable and heat it up. If you’re just charging your phone it’s unlikely to cause a problem but the more amps you pull the riskier it gets.
Here’s a helpful chart…
Edit: Even at harbor freight (cheap hardware store) a 50ft 12 gauge extension cord is about $40 and weighs 7 pounds.
I’ve always found gauge to be especially odd, because the number gets smaller as you go bigger, so at one point you can’t go any further even though you can go fatter.
16 AWG – 1.3 mm^2
14 AWG – 2 mm^2
12 AWG – 3.3 mm^2
10 AWG – 5.2 mm^2
For us from the civilised part of the world ;-)
However, as in Europe we have 230 V system, approximately half the cross section, as stated in the table above, is sufficient.
Edit: This is how the above text should be displayed:
Both are measurements of cross-sectional AREA and are defined in terms of square millimeters (mm^2), not mm.
Is it just me or is anyone else perturbed that the cable sizes in this infographic are all the same gauge?
It doesn’t make sense. Temperature difference does not depends on length.
Adding length creates more resistance which creates more heat. Thinner conductors can’t handle it as well.
And more surface area for heat dissipation. https://lemm.ee/comment/17115060
They cancel out.
