Clive Pounds asked:
A friend of mine was going to use a metal knife to free some stuck toast from the toaster. He’s always been told this is a huge no, no, but he said it would all be fine because he had rubber-soled shoes on. So is it true that rubber-soled shoes will protect you from an electric shock?
Dave: - I think the simple answer is it is possible they would protect you from an electric shock, but it’s not something I would ever recommend because it’s only “possible”. If you have a big, thick rubber sole then you're quite insulated from the ground, and if there’s no path for electricity to flow through, you won't get a big current going through you, so you'll be fine. It’s essentially a similar reason to why birds can sit on an electricity cable. They might be sitting on a very high voltage, but there’s no path for electricity to get down to earth through them so they’re absolutely fine, there’s no current flowing.
So, as long as you're just standing on your shoes you're not touching anything else, your feet aren’t wet so they're not creating a short path around the rubber soles to the ground, and you're not accidentally touching anything metallic - If you were touching the outside of a toaster which might be earthed then you might get a horrible current going through the knife, up your arm, then down the other arm, then you might be okay. But there’s so many things that could possibly go wrong, so unplug the toaster first.
Ben: - I think that sounds like a sound advice, and that by and large, don't stick metal things in electrical appliances.
It depends which way the electrical current is travelling. Insulating footwear can help to reduce the shock to ground if one hand is touching a live wire. However if the other hand is holding the metal body of a earthed toaster they will not help you because the current will pas from one hand to the other via the heart. This is the most dangerous sort of electric shock. Electricians who regularly have to work on live wiring using insulated tools are taught to always keep one hand in their pocket when working live and only use one hand to work with to avoid this risk. Soul Surfer, Tue, 27th Jul 2010
I agree with Soul Surfer. A current flowing from one arm to the other is extremely dangerous, even if your feet are well insulated from ground.
I think the toaster electrics are separated isolated from the case which leaves it at a floating potential not ground, there is no third prong for grounding the case.