Sadly there is little funny to say about Health and Safety. It is serious – and hugely important. For many, H&S might represent nannying and over-protectiveness. Top Gear liked to mock Hammond’s crashes. It is no joke for Mr Flintoff. We wish you a speedy recovery Freddy!
If you are tempted to start poking around a High Voltage installation, please please please take some training first. You know how much energy is in a tankful of petrol and how it might look if you released all of that energy with just a spark. An EV demonstrably has as much energy – Okay, maybe not quite as much if its range if only 200 miles not 400, but you know what I mean. An EV’s battery has enough energy to propel a 3 tonne vehicle for hundreds of miles. Do not risk channelling it in any unplanned routes.
There are some good training options around. We recommend the IMI’s series of courses, and Felten’s. We undertook many hours of training, which can be summarised in two rules;-
Rule 1: Try hard to never short live to neutral
Rule 2: Try really really really hard not to short live to neutral using your body.
Not only will all that energy give you severe burns at the points of entry and exit, but the electrical pulse will destroy your heart. Currents that pass through your chest – ie from one arm to the other – are extremely fatal. Though it is likely to be fatal in all circumstances. The degree of deadness is not of great concern once it exceeds 100%, you will still be deceased.
Anyone with an experience of car-tinkering is likely to have inadvertently touched a 12v battery live post to an earthed body. Makes you jump a bit doesn’t it? To illustrate the sparking available in a 12v 75Ah battery, we created this little video on Youtube. Now if you scale that up to the energy in an EV battery, you might have 400v and 750A. Individually, these are big scary numbers. Once you multiply them together the product is horrific!
As a bit of a sidebar, have you ever wondered why so many cows get killed in thunderstorms? No? Well I’m going to tell you anyway. Cows shelter under trees when it rains. When the lightning hits said tree, it travels down the trunk and then out through the ground in concentric circles. As the voltage spreads out, it reduces from millions of volts to nothing: the further you are from the tree, the lower the voltage is. The danger of electrocution comes to animals comes when they have feet that are different distances from the tree-trunk, as they have a higher voltage under one foot than the other. This potential difference then creates a current through watery flesh which kills them. Sadly for the cows, they have four feet, and so will inevitably have two of those four feet at different distances from the trunk. Humans can choose to stand with their feet at the same distance from the tree. In this case – in theory – they would be safe. DO NOT TRY THIS AT HOME!
Summary.
Health and Safety is important. DO NOT RISK YOUR LIFE ON HIGH VOLTAGE BATTERIES. If you do not know what you are doing, take training or pass the job to someone with experience and knowledge of High Voltage operations.