On 08/04/2020 01:00, Roger Hayter wrote:
newshound wrote:

On 07/04/2020 10:24, simon mitchelmore wrote:
testing, I think the insulation test would be reduced to 250v
instead of 500v which if I remember right is permissible in the regs.
Seem to recall that's how most neon indicator lights in sockets get
blown is by L to N ring main wiring testing at 500v!

Why should a neon blow under those circumstances? Double the current
through the ballast resistor, but still bugger all energy.

I suspect it might be the resistor that doesn't like four times the
expected power dissipation.

Yes you could very well be right My recollection was that ballasts were
about 1 Megohm making it a quarter of a watt at 500 volts. But Google
tells me my resistance is high by an order of magnitude. I guess
ballasts are around 1/8 to 1/4 watt sized.