Discuss Mains Tester screwdriver in the Electrical Forum area at ElectriciansForums.net

Welcome to ElectriciansForums.net - The American Electrical Advice Forum
Head straight to the main forums to chat by click here:   American Electrical Advice Forum

PJK

-
Reaction score
12
Hi I am hoping for some advice and to see if anyone is aware of this issue.

I was using a mains 240volt mains tester screwdriver ( the clear type, no battery, you just put your finger on the end cap to see if the screwdriver lights up, indicating 240v present). I was getting an indication on the earth wire of a light switch. When connected to the back box earth terminal the RCD did not trip and the RCD is working correctly. I used a Meger1552 to test the cables insulation and tested between all lines, switch wires and earth, no problems indicated. I tested the voltage reading on the earthwire and it was nil. I rewired the switch to the ceiling rose (it was easy to do) with new cable. The earth of the new cable also read an indication on the mains tester screwdriver yet it was definitely not shorting and was not connected at either end etc., Seems I was getting some sort of feedback through my body which caused the screwdriver to light up. Full PIR done on the installation and everything is fine.
Any comments would be welcome.
 
A phase tester is the most dangerous "tool" there is. Get rid of it and use an approved voltage indicator. There is absolutely no place for phase testers. They should be banned and their manufacture should be illegal.
 
A phase tester is the most dangerous "tool" there is. Get rid of it and use an approved voltage indicator. There is absolutely no place for phase testers. They should be banned and their manufacture should be illegal.


I totally agree
I also think that neon screwdrivers shouild not be included in a proffesional screwdriver sets

I think it gives a false approval to the DIYer or apprentices

Richard
 
I totally agree
I also think that neon screwdrivers shouild not be included in a proffesional screwdriver sets

I think it gives a false approval to the DIYer or apprentices

Richard

Indeed. That is one of the biggest problems - and not to single out any particular make of insulated screwdrivers as many reputable brands seem to include them.

I notice they tend to advise not using them as a screwdriver - it would be more sensible advising that they aren't used as phase testers!
 
I agree with the above comments that neon screwdrivers are not reliable indicators. They can also be dangerous. If the resistor in series with the neon inside is damaged or shorted or gets wet then you'll get 240v on your pinky.

I'm guessing PJK that it lit up on the incoming cpc. That would usually mean that the other end was not connected to earth or is broken somewhere. It will pick up a voltage by capacitance from the adjacent live conductors. A volt meter will still show 0V. Did you do a continuity test from the MET? Is the supply end connected to earth?
 
I agree with the above comments that neon screwdrivers are not reliable indicators. They can also be dangerous. If the resistor in series with the neon inside is damaged or shorted or gets wet then you'll get 240v on your pinky.

I'm guessing PJK that it lit up on the incoming cpc. That would usually mean that the other end was not connected to earth or is broken somewhere. It will pick up a voltage by capacitance from the adjacent live conductors. A volt meter will still show 0V. Did you do a continuity test from the MET? Is the supply end connected to earth?

As I found out about 30 years ago if you also get hold of anything connected to earth then you also get a belt as well.
 
Totally agree with all above. My assessor nearly failed me for having one.
What about the non-contact type, happy with it so far or am I being lulled into a false sense of security?
 
IMHO a waste of tool box and pocket space i havent and never have owned one. Th touch free voltage indicators are a bit better but mustnt be relyed on there good indication only but before works starts get the proper lamps and proving unit out and check!!!!
 
IMHO a waste of tool box and pocket space i havent and never have owned one. Th touch free voltage indicators are a bit better but mustnt be relyed on there good indication only but before works starts get the proper lamps and proving unit out and check!!!!

couldn't agree more when i was a lad helping my uncle he gave me one of they volt stick none touch voltage checkers, unbeknownes to me the battery was dead and i got a right belt!! he did it on purpose to teach me a lesson lol or so hhe said. I reckon he just didnt want my dad to lay him out at the time lol
:D
 
The continental view is that fuses can blow and give you a false indication of a safe conductor. The Steinel design has a high internal impedance so a fault in the instrument can't cause a short. If you use a fused instrument then you absolutley have to prove the instrument afterwards on a known source. I think you should on any instrument to prove dead.

An HSE guy told me once that the Steinel is effectively GS38 so long as it has the small tips and good leads etc. The true GS38 with the fuses in the probes gives you total protection in case you get a short across faulty leads eg if your lead scrapes against some sharp earthed metal and the probe is on a live terminal.

I had a boss once who nearly blew his face off by connecting an AVO across 415V busbars on the ammeter scale.

Stay safe. You're a long time dead. It feels like longer if you're maimed. Happy new year.
 
You MUST prove the voltage indicator before and after testing for voltage anyway so I can't see the problem.
 
I agree with the above comments that neon screwdrivers are not reliable indicators. They can also be dangerous. If the resistor in series with the neon inside is damaged or shorted or gets wet then you'll get 240v on your pinky.

I'm guessing PJK that it lit up on the incoming cpc. That would usually mean that the other end was not connected to earth or is broken somewhere. It will pick up a voltage by capacitance from the adjacent live conductors. A volt meter will still show 0V. Did you do a continuity test from the MET? Is the supply end connected to earth?

Thanks for that,n you have explained the false reading issue clearly. Full PIR conducted and earth continuity to MET is fine.
Cheers
 
Totally agree with all above. My assessor nearly failed me for having one.
What about the non-contact type, happy with it so far or am I being lulled into a false sense of security?

I disagree.

I think a volt stick is useful as an indication.
but it can't replace a contact tester.
even these aren't trusted as we buy proving units

Iif you find something dangerous and want to take a photo showing something was left live and dangerous
 
Back in my apprentice days i used one to test a cable in the loft it showed dead and when i touched it almost put my foot through the ceiling as it WAS live ! ever since i have never used one only for kids to undo batt covers when they replace them.
 
Last edited by a moderator:

Reply to Mains Tester screwdriver in the Electrical Forum area at ElectriciansForums.net

OFFICIAL SPONSORS

Electrical Goods - Electrical Tools - Brand Names Electrician Courses Green Electrical Goods PCB Way Electrical Goods - Electrical Tools - Brand Names Pushfit Wire Connectors Electric Underfloor Heating Electrician Courses
These Official Forum Sponsors May Provide Discounts to Regular Forum Members - If you would like to sponsor us then CLICK HERE and post a thread with who you are, and we'll send you some stats etc

Electrical Forum

Welcome to the Electrical Forum at ElectriciansForums.net. The friendliest electrical forum online. General electrical questions and answers can be found in the electrical forum.
This website was designed, optimised and is hosted by Untold Media. Operating under the name Untold Media since 2001.
Back
Top
AdBlock Detected

We get it, advertisements are annoying!

Sure, ad-blocking software does a great job at blocking ads, but it also blocks useful features of our website. For the best site experience please disable your AdBlocker.

I've Disabled AdBlock