0
\$\begingroup\$

I'm not an electrician and I have some basic understanding of how voltage testing pens work. I haven't had an incident with them before but I'm still quite concerned about their safety mechanisms.

I do realize there are several types of testing pens but I'm using are relatively cheap and common and look like this:

Voltage Testing Pen

I have 2 questions:

  1. How safe are such common Voltage Testing Pens?
  2. How can I test the safety of those devices myself at home?
\$\endgroup\$
  • \$\begingroup\$ "How safe" is a very relative question. "How safe is it to drive a car?". The pen is pretty safe. \$\endgroup\$ – Damien Jan 21 at 2:54
1
\$\begingroup\$

That's what I'd call a neon screwdriver, it has a neon indicator that lights by mains voltages starting at around 70V

it's main advantage over the non-contact voltage detectors are that it's always ready because it does not have batteries that can go flat.

its disadvantage is that it is less sensitive and requires physical contact with the conductor to operate. the one I have here is stamped 100-500V

less than 100V you don't get reliable detection, past 500V there's a risk of electric shock if the insulation fails (ther insulation internal to the resistor is a point likely to fail if the safe voltage is exceeded).

enter image description here

Non-contact voltage detectors on the other hand sense the electric field in the proximity of live wires. it can detect voltage therough the insulation on the cable and its plastic tip. Its nternal electrionics amplifies the signal so it gives a stronger visual indiccation and a audio indication too. the one I have is rated 50 to 1000V, so not only is it more sensitive, but also it has better insulation, requires two AAA cells which last a long time.

For safe testing, test it on an outlet that's protected by an ELCB / RCD. with such a set-up a failure could be unplesant, but not life-threatening.

|improve this answer|||||
\$\endgroup\$
0
\$\begingroup\$

The voltage testing pen is reasonably safe if you use it properly. Number 1: be sure to touch only the insulated handle. Number 2: keep your other hand in your pocket so it can't make contact with anything (this avoids the chance of any current accidentally going through your body if the insulation should fail). However, there is no way you can test the safety of these devices without specialized equipment. You have to rely on the integrity of the manufacturer. If you are concerned only use testers from reputable manufacturers such as Fluke and Milwaukee.

|improve this answer|||||
\$\endgroup\$
  • \$\begingroup\$ you have to touch the brass button else it won't work \$\endgroup\$ – Jasen Jan 21 at 2:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.