On 06/04/2020 12:26, George Miles wrote:
But when an electrician gives the circuit an insulation test they cannot isolate the USB socket so what do they do?

Or do they need an isolating switch?

Simpler and easier not to have any.

[george]

On Monday, April 6, 2020 at 11:26:53 AM UTC+1, simon mitchelmore wrote:
Does anyone know if the USB charger is permanently energised (when fitted as part of 13A sockets) or whether it's turned on via a micro switch when the USB plug is inserted (I'm guessing the former)?

I know the current draw of a USB charger is tiny when open circuit but, being 'old school', I always remove the USB lead plug when not charging our phones but this may be the cause of several USB leads becoming faulty. Maybe I should leave the USB leads connected permanently and relax?

I'd guess they are designed to tolerate 500 volts or so from a megger?