Definitely not when wet - as happens in thunderstorms.
Agreed. Damp or wet sand conducts electricity via the film of moisture, but when my front garden was excavated to fix a blocked drain, I was surprised at just how dry the sand was 4 foot down (above the water table). After several weeks of hot sunny weather followed by a sudden thunderstorm, it takes some time for water to percolate down through the top 9 inches of soil into the sand below. When lightning strikes a nearby tree after a long drought, current follows the path of least resistance underground when the sand is still dry. For my house, these paths include the mains supply, metal gas and water pipes, plus telephone and various cable TV wires.
We ended up pounding in at least 4, sometimes 6 grounding stake encircling our radios, then bonding all rods together with solid 4 gauge grounding wire to create a good, and safe, common Earth ground plane.
When I visted an amateur radio site in Pennsylvania with a friend who is a radio ham, the site owner had blasted a large pit into the hillside with explosives and lined it with thick Copper strips and filled it with rain water, to get a decent earth for his transmitter. My single puny earth rod hammered into sandy soil is a pathetic attempt to reduce damage the next time there's a lighning strike close to my house. Having abandoned old fashioned telephone and wired internet in favour of full fibre-to-the-premises, that's one less entry point for high voltages caused by a lightning strike. I have two blown hardware firewalls, a blackened telephone answering machine, plus a failed Ethernet chipset in a laptop, which all died during previous strikes.
They aren't used in continental Europe, either. So where are those outlets commonly seen? UK? Parts of Asia?
It's quite normal to have at least two dual 13A
switched sockets in each room of a modern UK home, apart from the bathroom where it is against regulations due to safety concerns. My house which is 50 years old has single unswitched 13A sockets, because the construction company was penny pinching. They even installed cheap old-fashioned fuses in my mains consumer unit, instead of more expensive MCBs. My home's lighting circuits are protected by 5A fuse wire and the two 13A socket ring mains by much thicker 30A fuse wire. When a fuse blows, it's time to reach for a torch, the card with different gauges of fuse wire and a flat-bladed screwdriver, to replace the link in the ceramic holder. A fiddly job, especially at night. N.B. There are two 100A breakers protecting the whole unit and yes, I know I could have a modern consumer unit fitted with MCBs.
In addition, UK 13A-rated mains plugs contain a cartridge fuse, available in 2A, 3A, 5A, 7A, 10A and 13A flavours. This fuse protects the lead up to the appliance (lamp, toaster, kettle, computer, TV, monitor). For better protection, low current table lamps should have a 2A or 3A fuse fitted in the 13A plug. I can usually get away with a 7A mains plug fuse in 10A-rated IEC leads connected to ATX PSUs. 3kW fan heaters need a 13A fuse in the mains plug. Although you can select the fuse rating yourself, most people don't bother because prewired 13A-rated plugs are usually sold with the appropriate fuse value.
Better quality High Rupture Current mains fuses are frequently filled with fine-grain sand which surrounds the metal fuse link, to reduce the chance of high-current restrike through the conductive layer of vapourised metal, which may be deposited inside the fuse. This is one instance where sand is used as a protective safety feature in electrically powered systems.
2) Hybrid "shut-down" from Windows won't be happy with AC power loss (unless, user turned off hibernation from admin's command line after first OS install), because as default - Windows "shut down" is just a fancy sleep mode. Prepare to see "PC wasn't shut down correctly" error at least once per 3-4 "power ons" (assuming recovery menu wasn't turned off).
It took me years to work out why I was getting "PC wasn't shut down properly" error messages, when I booted up alternative versions of Windows (XP, 7, 10) from separate drives in an old PC, then returned to the main boot drive. It was only when I knobbled "Fast Shutdown" in Power Options and wiped hiberfil.sys with "powercfg -h off" for good measure, that everything returned to normal. I now disable these "annoying" features on all my Windows systems and don't care about potentially longer startup times.
3) As mentioned earlier , CMOS battery will wear off faster when computer isn't connected to AC (since it will be discharging and charging A LOT more),
I'm not entirely sure if the CMOS battery does get charged from the computer's PSU. The ubiqitous CR3032 is a "primary" cell and (in theory) it's not designed for recharging. Conversely, "secondary" cells (lead-acid, NiCd, NiMh, Lithium) are designed to be recharged. I'm not saying you cannot recharge a primary cell, having ignored the warning on NiCd chargers myself and "topped up" old Alkaline AA cells for prolonged life.
Instead, I'm asking if it's normal design practice on computer motherboards to recharge CR3032 cells. I've only encountered one mobo where this seemed to be the case. A multimeter showed over 3 Volts on a CR3032 in situ with the computer powered on, but when I switched off and removed the CR3032, it only read 0.7V which explained the wrong date and lost boot information. Any thoughts?
