CHECKING HOUSEHOLD ELECTRICAL EARTH AND EQUIPMENT PROTECTION

[Dal]

If I run a switched PSU from a UPS with smoothing, all is well right?

[RetroGamerUK]

Ok Simbo I you're right, I bow to your infinite knowledge of everything, I and every other electrician in fact the I.E.E. are obviously wrong.

[spiny]

road worthy hahahahahahahahaah


rusty bits of rotted subframe junk
like most of the power grid for sure...!

it people 'collecting' old cars kill the most on the road now

the worst accidents are caused by people with 'road worthy ' cars
hence the many scrapage schemes

total nads, as usual.

[1024MAK]

Well the company that I am employed by uses spurs for most of it's power feeds. Some are many miles long (but at a higher voltage than 240V). Not only that but most of these supplies are "earth free" as in the supply wiring has no intentional connection to earth. The metal equipment covers and parts are however earthed for equipment over 110Vac.
We use a very varied mix of equipment, including motors, relays and electronics including microprocessor and computer equipment.
Some of this equipment has been in operation since 1970. We do have failures (locating and fixing these is my job) but most are caused by poor connections or cables (or contractors) that have degraded (or been hit by other department staff / machinery).

As far as electrical safety goes, this is the reason for the earth connections in electrical wiring - if a live conductor comes into contact with a metal case part, a fault current will flow and blow the fuse (or cause the MCB to trip out). "Modern" electronic equipment takes advantage of this, using the earth as a drain wire.

As to regards lightning strikes - if a metal cable going in your home suffers a direct strike anything connected to it will be toast! If your home gets hit anything that the current flows through will be damaged. And earthed items are the lightnings favorite path to earth!
Even a nearby strike can cause much damage and a surge protector is only a limited defense. I do recommend using surge protectors, but just don't expect them to protect against such high energy sources!

[simbo]

a ring main in any ac system supply residential
differs from the system most retros expect as supply

the whole point of post like this is dont spur off a ring
is to wake people up to the new laws that are europe wide
i have become aware of myself
so if you use an extenssion from a normal ring main
use an anti surge filtered type extenssion for old pc and switchmode {analogue}
its a pitty so many so called electricians dont offer to wire a seperate filtered computer only 4 way sockets
pre filered

instead they say your right or wrong
instead of making a few quid offering this service...

so stupid ....