Display results as :

Rechercher Advanced Search


Latest topics
January 2019

Calendar Calendar

free forum

free forum

Use of a Voltage Detector as a Means of Quickly Finding Unearthed Metalwork

Go down

Use of a Voltage Detector as a Means of Quickly Finding Unearthed Metalwork

Post by terry gray on Tue Aug 21, 2012 6:25 am

Continuing with the theme of non-invasive testing, I very much recommend the idea of using a voltage detector (stick) as a quick an safe method of finding out whether or not a piece of Class 1 equipment is unearthed or extraneous metalwork has a charge on it. As you will know, these devices pick-up the electrostatic field from AC mains voltage at between 100 and 1000 V and when held near un-sheilded wiring or equipment they will signal the presence of AC mains voltage.

Another use of the device which isn't well known, is that if a peice of Class 1 equipment is un-earthed the voltage detector will signal the presence of the AC supply from approximately 25mm away, as there is nothing in place to sheild the electrostatic field. Of course, the equipment has to be energised to detect this condition, however, one should be aware that the item may also be charged with an AC voltage via a fault. Therefore, it will need to be safely isolated and a long lead R2 continuity test performed from a known earthed reference point before the item is touched or any remedial work done.

When carrying out periodic inspections in the past, I have come across 2 metal fluorescent light fittings which have had 230 Volts on the case due to a wiring fault. This is why the voltage detector used in this way is such a useful device. It does however have its disadvantages, in so much that it can give a false indication at times, however, when used by a competent person and checked that it works correctly before use, it can be a great boon when undertaking an assessment or periodic inspection.

The device I use is Di-log PL 107, as I find it has an ideal sensitivity for the purpose explained and I have also mounted it on a telescopic pole when cheking Class 1 fittings at height to avoid the use of access equipment with the added advantage that the device gives an audible indication.

terry gray

Posts : 16
Join date : 2012-02-29

View user profile

Back to top Go down

Back to top

- Similar topics

Permissions in this forum:
You cannot reply to topics in this forum