Megger Test Feeders

[mstrlucky74]

When you Megger a feeder, where do you test? Both ends? Thank you.

 

[Rewire]

When you Megger a feeder, where do you test? Both ends? Thank you.

We check for continuity then meg from one end

 

[kwired]

We check for continuity then meg from one end

If you don't have continuity (in the nearly zero impedance range) from one end to the other you have a problem.

Otherwise you should have same reading from each end.

 

[mstrlucky74]

Would you usually always Megger all feeders/wires or only down to certain size or whatever the spec tells you?

 

[Rewire]

If you don't have continuity (in the nearly zero impedance range) from one end to the other you have a problem.

Otherwise you should have same reading from each end.

That is why we check continuity first.:thumbsup:

 

[TimK]

Would you usually always Megger all feeders/wires or only down to certain size or whatever the spec tells you?

We always take an Ohm reading on feeders, but only MEG when spec'd. Just bid a job that required all new wires installed be megged, happened to be 17 new HVAC units, okay if that's what you want, price it and that's what we do:happyyes:

 

[zog]

Would you usually always Megger all feeders/wires or only down to certain size or whatever the spec tells you?

Depends on what you are calling a feeder. Really just what the spec says, but it is not in specs as often as it should be, anything 480/277 for sure, after that it really depends on what it is feeding.

 

[hillbilly1]

Some AHJ's require megging the service conductors before they will allow the service to be energized, not really a bad idea, the cost of meggers have come down substantially over the years. I had an old analog Megger that we paid around $600 used 15 years ago, and it was due for another recertifacation, looked at the price of the new digital ones, and bought a new one for around $700 that does everything I need it to do.

 

[augie47]

Some AHJ's require megging the service conductors before they will allow the service to be energized, not really a bad idea, the cost of meggers have come down substantially over the years. I had an old analog Megger that we paid around $600 used 15 years ago, and it was due for another recertifacation, looked at the price of the new digital ones, and bought a new one for around $700 that does everything I need it to do.

Do you at what reading they reject the installation ?

 

[hillbilly1]

Do you at what reading they reject the installation ?

It's been at least 10 years since I have done work in that jurisdiction, I don't remember if the inspector gave an actual minimum or not, we just tested it and documented the readings to give him.

 

[brian john]

It's been at least 10 years since I have done work in that jurisdiction, I don't remember if the inspector gave an actual minimum or not, we just tested it and documented the readings to give him.

And I'd bet the inspector either did not know or went with the old 1 megohm from "Stitch in Time"