Help with new Fluke T140 Voltage Tester

[Elidor]

Good afternoon all.


Have just acquired a new Fluke T140 voltage tester but am a bit conserned about how it’s working. First thing i noticed is that when the L2 (+) probe makes contact with either L, N or E there is a buzzer sound and the LED “Single Pole Phase Test” is illuminated. This LED and the associated buzzer continues to be present when both probes are used and the voltage reading is taken. Im not convinced it should be making this noise as i don’t recall the testers used in the college behaving in this way.

What is this “Single Pole Phase Test” exactly? The feature appears to be described in the manual as a means of identifying a conductor yet the last point in the manual states that its not appropriate to use this method and that a double pole voltage test is always required. Im confused why this feature is there if the device itself recommends it should not be used?

 

[Johnny-G]

If it's buzzing when you just touch that probe to L,N or E then there must be voltage on all 3 as it basically identifies 'live' conductors assuming it's working correctly of course.
It's no good just using the one probe for double pole tests, as, funnily enough, you need to identify both poles and whether there is a circuit

 

[Elidor]

Im testing it on a ceiling light. When the switch is in the ON position the unit confirms voltage between L & N and L & E and no voltage between N & E as expected. In the OFF position im not getting any voltage accross any terminals confirming the circuit is dead yet the buzzer still sounds and the LED “Single Pole Phase Test” is illuminated when the L2 probe makes contact with any terminal. Is this normal? What exatly is the unit detecting and how?

I'm very new to the trade and naturaly a very curious person hehe

 

[Johnny-G]

If you are still connecting both probes then that's indicating continuity.
If you are just using the L2 probe then, as I mentioned earlier, it is detecting voltage.

 

[Elidor]

* UPDATE *
Thanks Johnny for your comments, the point i was making was there should be no voltage and if there was I would expect the unit to tell me but the the unit reads No Voltage on the LED scale or the LCD display. After some investigation with a another standard multimeter type there is an unusual voltage figure of 66.9v. I dont understand why the T140 doesnt show this value on the LED or digital display but it does give a LED and buzzer warning which is what triggered the thread as i wanted to establish whether the unit was faulty.

I have since tested the T140 unit on another circuit and it does appear to be functioning correctly / how I asume it should so the unit seems fine. The wierd problem i have now is why there is such an unusual voltage reading on the lighting circuit when its off lol.

Anyone encountered anything like this before?

 

[chrisreid186]

i've had weird voltages on tncs when the main earthing conductor was loose, have you done a zs test?