Fluke 334 strange reading

[flywright52]

Using a Fluke 334, I was troubleshooting a 480V 3 Ph circuit today, checking each of the legs to ground (chassis). I pulled the fuses and checked two of the legs and got a normal ("OL") reading to indicate the leg was not shorted. On the third leg, my meter was alternating between "OL" and "0" (zero). I have never this seen indication before and could not find it in any of the literature. Anyone seen this and know what it means?

 

[JFletcher]

Corner grounded delta?

 

[GoldDigger]

My guess is that the ohmmeter function is being confused by phantom or leakage voltage on that one leg.
Are you using autorange for the ohm measurement? Can you force an ohms range with that meter?

 

[flywright52]

My guess is that the ohmmeter function is being confused by phantom or leakage voltage on that one leg.
Are you using autorange for the ohm measurement? Can you force an ohms range with that meter?

It was on ohms range. It could be that the cabinet had some phantom voltages. I sent a question to fluke. We'll see if they answer.

 

[mike_kilroy]

U get that when u use ohms scale on circuit with voltage.

Change to ac and dc volts and u will see it.

 

[Cow]

If you're checking for ground faults, try a megger instead. Regular meters don't have the voltage behind the test to punch through any potential issues like a megger can. I use a Fluke 1507.

 

[ptonsparky]

The pulse of a nearby electric fence can have that affect, esp when they use the building GES as their ground. So can a coasting motor, as in a fan motor being slowly turned in the breeze.

 

[flywright52]

Thanks for the replies. A Fluke support technician confirmed that was the reading when voltage was present in a resistance measurement.