Some daft questions...

[zetecuk]

The lights in our house always dim when turning on either of the showers. Is this normal or does it indicate a problem? The wiring is mid 70s and the fuse box is a modern looking one with RCD and MCBs.

Also... Is it "safe" to test an electric screwdriver thingy on a real live wire, to make sure it really does glow?

And why don't electric shower cases seem to be that waterproof?

 

[sterose]

"The lights in our house always dim when turning on either of the showers. Is this normal or does it indicate a problem? The wiring is mid 70s and the fuse box is a modern looking one with RCD and MCBs."

My setup is identical to this, house built in mid-70's, MCB's, and the rest.

The question is how much do they dim?
Are we talking, from light to pitch black, or is it just slightly.

My light dim a bit, but not really noticable unless you look at the light bulb.


"Also... Is it "safe" to test an electric screwdriver thingy on a real live wire, to make sure it really does glow?"

I dont know what you mean by 'real live wire' - I would assume that 'live wires' are what it's supposed to test in the first place...

 

[zetecuk]

Well I did say they were daft questions

 

[sterose]

zetecuk, i'm gald you are one of a few people on this forum who have a sense of humour.

The dimming lights question is not stupid however.
It is the extent of the dimming that matters.
If they dim just slightly, it's fine - if they dim lots, you have a slight problem.

But dont worry, as long as you are not in the dark, it will be fine - incidentally, how long has the shower been installed (if its been in years without problem, you will be fine).

 

[zetecuk]

No, they only dim a little - what causes it though? Its like the supply to the house can't handle the extra power? They brighten up again when turning it off. It has always done it though, with the old and new showers, upstairs and downstairs. Not had any problems, it just looks a bit dodgy, like the shower has been wired into the lighting circuit (it's not, I've checked!)

And the electric screwdriver thing, well basically I want to make sure it works, but I'm too scared to test it on a wire I know to be live!

 

[sterose]

Put some gloves on when using the screwdriver...

"Not had any problems, it just looks a bit dodgy, like the shower has been wired into the lighting circuit (it's not, I've checked!) "

Lighting circuit? No.
Basically (please correct me...), lights are sensitive to voltage drop - there are certain tolerances allowed before it becomes a cause for concern. Like I said, my shower has been in more than a year without problem, and the lights dim slightly. In fact, ive never used a shower that doesnt cause dimming of the lights.

 

[breezer]

zetecuk, the lights dim because of "voltage drop" (but we wont go too much into that) basically you are right in the fact that there is not enough "power" to run both at 100%


if you have a screwdriver with neon and you wish to test it you could put it onto a known live item, but i am not going to suggest any particular item. but only use a proper insulated "tester" and NEVER test it on a plug. and you will probably find that wearing a glove when "testing" will give you false readings

as for why are showers "cases" not that waterproof is because they do not need to be, they have to be electricaly isolated and water resistant

 

[flashbang]

Before undertaking any electrical work, I always stick my screwdriver tester into a known live wire to confirm it works...... I've never been blowed up!!!
It's quite safe, I know it seems a bit worrying when you have to put a finger on the other end of the driver to complete a circuit bit it doesn't hurt........ much!!
I can only imagine that breezer means by "NEVER test it on a plug" is because you would have to plug into a live socket, and the back of the plug would have to be removed in order to test it....! That would very likely hurt LOTS!!!
As long as you have a tester for mains, and NOT a 12v automotive continuity tester, they are perfectly safe.
BTW. My lights dim when the shower is operated too, and have done in every house I've lived in, I'm sure it's perfectly normal.
Flashbang.

 

[sterose]

zetecuk, the lights dim because of "voltage drop" (but we wont go too much into that) basically you are right in the fact that there is not enough "power" to run both at 100%


if you have a screwdriver with neon and you wish to test it you could put it onto a known live item, but i am not going to suggest any particular item. but only use a proper insulated "tester" and NEVER test it on a plug. and you will probably find that wearing a glove when "testing" will give you false readings

as for why are showers "cases" not that waterproof is because they do not need to be, they have to be electricaly isolated and water resistant

Yes, the glove thing was only a joke, it needs a connection the body to actually light up.

I dont see why you cant test it on a plug though...

 

[breezer]

as flashbang said, to test it on a plug you have to have it open, which means it can be touched, and supose it is in a non switced socket (some one will) how you going to unplug it?

 

[ban-all-sheds]

as flashbang said, to test it on a plug you have to have it open, which means it can be touched, and supose it is in a non switced socket (some one will) how you going to unplug it?

Very carefully...

 

[Sam Gangee]

If you are not confident about testing your neon screwdriver, connect a thin insulated wire to its end by pressing a ball of "Blu-Tack" onto it. Connect the other end of the wire to a ground point (cold water pipe or c/h radiator should be fine but NOT a gas pipe). Touch the screwdriver tip to a live terminal and see the neon glow.

 

[breezer]

personally i hate neon "testers" ever since i had to go and check a supply where a neon tester was used, and it said it was live, but the appliance wouldn't work. yes the live was live, but the joker who connected the neutral forgot to strip it.

 

[masona]

If you are not confident about testing your neon screwdriver, connect a thin insulated wire to its end by pressing a ball of "Blu-Tack" onto it. Connect the other end of the wire to a ground point (cold water pipe or c/h radiator should be fine but NOT a gas pipe). Touch the screwdriver tip to a live terminal and see the neon glow.

Can you get a neon tester with a crocodile clip + wire like they do for a car 12v ?

 

[breezer]

no, becasue of the mains voltage