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Posted By Topic: E M Radiation

Dec 03 2019 10:11

Hi There
I have a customer who has two seperate 15a charging
stations for there electric cars and they have become concerned about the effects of em Radiation because of the increase in current now flowing through there switchboard which is in the centre of there house .
They are only using what anybody could use on a Domestic 60a Supply, so cant see that it would be a concern .
anyone with any understanding on these matters ?

Dec 03 2019 11:10

Yes there are magnetic fields (NOT "radiation") around a.c. wiring when it's carrying current.
They are tiny, because the fields around A & N almost completely cancel each other out. And they follow the inverse square law, so they will be undetectable without very special equipment.
There's way more field around a fridge magnet than a typical household cable, as can be proved by holding a compass near each.

Anyone who worries about these should stop using a cellphone, which IS emitting "radiation" and is typically right next to their brain while transmitting.


Dec 03 2019 14:21

They should also avoid the sun, the most dangerous source of radiation we're typically exposed to. If they don't want to bathe in its glorious DNA mutating rays they'd better have good curtains - you might be able to sell them some.

Dec 03 2019 14:26

Also never fly in an airplane the radiation is a lot more at 32000 feet

Dec 03 2019 14:34

Anything warm is an emitter. :D

If it is emitting strong enough, a hotplate, and you are close enough, touching it, then it burns.

There is also "high-energy" emissions, like an electrical arc, or the sun, or radio-active decay that throw out what's called ionising radiation. These fall further into two categories of EM based and particle based.

EM based have to be ultra-violet (UV) or higher, eg: X-rays. Anything below UV (visible and RF) is not ionising and can only cook via intensity.

Generating X-rays requires something like 30,000 volts in a vacuum. I'm not sure what that means for 220 kV distribution lines.


Dec 03 2019 22:42

If they are seriously worried about EMR and have money to spend, install screened cables. The VFR motor cables would be best but cost heaps, neutral screen twin (with the screen as earth) or armoured cable will reduce emissions to a negligible level if correctly earthed.
But you can't argue with the tinfoil hat people.