Re: Electric Field Detectors, again

[omara]

Referring to my previous question (thread238-22832) on voltage detectors vs. electric field detectors, I finally found what I was looking for.

An electric field detector for use of utility personnel to alarm them in case of inadvertently energized equipment was produced by Avo, the Megger Osprey LA501 (for distribution level voltages) and the LA502 (for transmission level voltages). It is now available from Osprey Limited (UK) and is called the Live Alarm 5060D (distribution networks), 5060T (transmission systems) and 1625-R (for 16.6 and 25Hz railway systems).

MY QUESTION:
Does anyone have experience with using any of these devices, especially as an additional safeguard for distribution linesmen? How reliable were they? Were there so many false alarms from surrounding sources that linesmen did not use them? Were they able to survive field working conditions? Did you have to get the manufacturer to adjust their sensitivity?

THANK YOU FOR ANY FEEDBACK.

 

[jbartos]

Suggestion. It will be better to visit

http://www.avointl.com/

for their literature and recommendations since the safety is involved.

 

[busbar]

An added phrase to the OP’s definition of "inadvertently energized" may be “not recognized to be..." or "not safely determined to be deenergized.”

It seems like the differences in “voltage detectors vs. electric field detectors” may be marketing or regional terminology; both seemingly based on the generally accepted concept of non-contact AC-voltage detection. Non-contact AC-voltage detectors have an effective and proven operating history for a decade or more, but like any safety appliance require formal training and extensive, intimate, end-user field experience to be effective—particularly for false-positive readings and the ability to treasonably determine the {admittedly sometimes subtle} differences in indication and sensitivity. Because of the extreme variability in real conditions, assignment of a hard number {id est, "V/m" capability} may be viewed as purely bureaucratic, and entirely “CYA” to some mid-level administrator that is virtually clueless about the device’s operation and limitations, short of some printed text he may have reviewed.

In no case are non-contact testers intended to be used by less than fully trained/qualified field personnel. A critical part of that craft training is clear and demonstrated recognition of tool limitations, especially where it becomes a daily, root life-or-death issue.

Increase in user safety far offsets occasional non-productive or delaying false indications, that should be clearly understood and anticipated. A user should employ another method in its place, or use alongside another method wherein that person has established confidence in whatever other device; otherwise the worker should be barred from the immediate task at hand and limited to lesser duties for the sake of themselves, their peers and families. The no-questions, “never candy-assed here” “tough dude” stance should have been gone well before the turn of the century.