AVI (Approved Voltage Indicator) - Common Misconceptions

[1Justin]

For I2C : My Dilog AVI has an 18K input impedance. High enough normally of course (if no other leakages), but too low for it to be driven anywhere close to 230V by a Martindale proving unit (which can only drive about 3mA, - hence about 60V on testing the AVI).

 

[telectrix]

i reallyneed to check the input impudence of my AVO 8.i forgot what it was back in 1982.

 

[PEG]

I find it hard to believe,that several electricians suggest the test described,by the OP...one numb one...but plural?

The fundamental requirements,are to both understand how the test equipment functions,and how to use it,to discover whether safe or not.

Experience of the various scenarios,where line voltage can occur,would make ALL the necessary combinations of testing,second nature.

Line/neutral reversed,a live neutral,live earth,or all live...are all possible or probable occurrences,and all testing should indicate such.

The gentlemen advising otherwise,have possibly never inspected a connected burger bar,by first putting one probe on the yard surface,and the other on it's brightwork

 

[ipf]

If you're testing for isolation it should be isolated. If so, why worry about an rcd tripping.
It should all be dead, so test it all.
Fault finding may be different.....but it should have tripped, anyway.

 

[dmxtothemax]

my papa used to say - Never try to argue with a fool, they will only force you down to there level, then beat you with experience !
Some people just don't want to listen for what ever reason, you just learn not to even try with those sort of people !

 

[PEG]

Just an appendage,to my previous post,which mentioned correct understanding of a test instrument,would be to remember that an AVI is not only used to check for safe isolation.

It is as handy,though not it's primary use regarding this conversation,for proving a voltage present.

A quality AVI,with maybe resistance and DC capability,can be a fine,compact troubleshooting device.

I have an old TPT220,which stays in the glove box,or hand luggage...and it's paid for itself a hundred times over

 

[static zap]

Some people just don't want to listen for what ever reason, you just learn not to even try with those sort of people!

I still feel the urge to get them to notice -some effort was used...and wonder why ! (or/Not)
Safe .. negligible volts anywhere !