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Do you own a Megger

  • Yes I own a Megger

    Votes: 50 75.8%
  • No I do Not Own a Megger

    Votes: 11 16.7%
  • Whats a Megger?

    Votes: 5 7.6%
61 - 75 of 75 Posts

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Safety Pin Member
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2,255 Posts
I'd thought of megging as common for larger feeds and such. I gather though
that some of you guys use it for every cct. Is that correct? If so, what would
the procedure be?

Here's what I'm thinking. Return to property to do finishing. Bonds & neutrals
are already terminated at panel. Install everything that won't be damaged by
testing. This'd be rcptcls and switchs. Leave off lights, dimmers, timers.
Temporarily make connections where dimmers and timers will be installed.
At each box where something (like a light) isn't installed, pull the leads out
and separate so they won't short to each other or the box.

At the panel: Prior to installing breakers - attach one lead of megger to
panel case then, one by one, attach other lead to each of the "hots".
Last step would be to investigate any low readings.

This would be somewhat time consuming but if it even occasionally found
a problem, it'd be worth it. Especially if that problem wouldn't have been
found anyways by tripping the breaker.

So, if some of you have been doing this, or something similar, I'd like to
hear how it's worked out.

As a side note - I've worked in tract housing - Zero chance of this sort of
testing happening there.

Thanks,
P&L
 
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Old Grumpy Bastard
Joined
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61,265 Posts
I'd thought of megging as common for larger feeds and such. I gather though
that some of you guys use it for every cct. Is that correct? If so, what would
the procedure be?

Here's what I'm thinking. Return to property to do finishing. Bonds & neutrals
are already terminated at panel. Install everything that won't be damaged by
testing. This'd be rcptcls and switchs. Leave off lights, dimmers, timers.
Temporarily make connections where dimmers and timers will be installed.
At each box where something (like a light) isn't installed, pull the leads out
and separate so they won't short to each other or the box.

At the panel: Prior to installing breakers - attach one lead of megger to
panel case then, one by one, attach other lead to each of the "hots".
Last step would be to investigate any low readings.


This would be somewhat time consuming but if it even occasionally found
a problem, it'd be worth it. Especially if that problem wouldn't have been
found anyways by tripping the breaker.

So, if some of you have been doing this, or something similar, I'd like to
hear how it's worked out.

As a side note - I've worked in tract housing - Zero chance of this sort of
testing happening there.

Thanks,
P&L

That is exactly how I have done it for sometime now.

Better to know there is an issue with a circuit and look for it than have it happen later down the road.

More than once I traced out a circuit and went box to box with the megger until I found a wire pinched down in a connector or the box clamp on a romex cable.

Some guys really like to tighten clamps to excess.

I will add I've found more problems with romex, UF and Sj type cables than MC or conduit circuits by far.
 

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Band Member
DIYer Extrodinaire
Joined
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6,964 Posts
I'd thought of megging as common for larger feeds and such. I gather though
that some of you guys use it for every cct. Is that correct? If so, what would
the procedure be?

Here's what I'm thinking. Return to property to do finishing. Bonds & neutrals
are already terminated at panel. Install everything that won't be damaged by
testing. This'd be rcptcls and switchs. Leave off lights, dimmers, timers.
Temporarily make connections where dimmers and timers will be installed.
At each box where something (like a light) isn't installed, pull the leads out
and separate so they won't short to each other or the box.

At the panel: Prior to installing breakers - attach one lead of megger to
panel case then, one by one, attach other lead to each of the "hots".
Last step would be to investigate any low readings.

This would be somewhat time consuming but if it even occasionally found
a problem, it'd be worth it. Especially if that problem wouldn't have been
found anyways by tripping the breaker.

So, if some of you have been doing this, or something similar, I'd like to
hear how it's worked out.

As a side note - I've worked in tract housing - Zero chance of this sort of
testing happening there.

Thanks,
P&L
I remove the neutral as well ... Test between:
L - N
L - E
N - E

the neutral to ground test will keep your afci's happy :)
 

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Old Grumpy Bastard
Joined
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61,265 Posts
I remove the neutral as well ... Test between:
L - N
L - E
N - E

the neutral to ground test will keep your afci's happy :)
So happy I've missed out on playing with them. From all the talk here they sound like a total pain.
 

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Band Member
DIYer Extrodinaire
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Just curious how many members own a Megger.
Just here to give you a hard time .... Which product from Megger © are we talking about ? :jester:

Not often I see you slip up (Never ?) ... so I just had to jump on it :laughing:


btw ... I voted "What's a Megger" :tt2:
 
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Old Grumpy Bastard
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61,265 Posts
Just here to give you a hard time .... Which product from Megger © are we talking about ? :jester:

Not often I see you slip up (Never ?) ... so I just had to jump on it :laughing:


btw ... I voted "What's a Megger" :tt2:
I sure hope the others that voted as you are just joking!
 

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Safety Pin Member
Joined
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2,255 Posts
I remove the neutral as well ... Test between:
L - N
L - E
N - E

the neutral to ground test will keep your afci's happy :)
Guess I could do N - E all at once in an MLO panel by disconnecting
either the N or E feeding the panel.....
Could do the same, I think, in main panel if I also removed the bond
screw.
Not sure it'd be worth it to me......maybe.
P&L
 
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DIYer Extrodinaire
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Maybe I'm just stating the obvious here ... but watch out for hardwired stuff in an existing house :eek: .
Alarm systems, door bell cct ... etc !


I've heard if you Meg with L and N connected together, to ground, that you won't see the magic smoke ... but I can't confirm

Maybe @brian john can comment.
 

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Old Grumpy Bastard
Joined
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61,265 Posts
I never owned a megger because everywhere I have worked either supplied them or I asked them to supply one.
Now I want one and have zero use for it!
Sounds like me and the M12 bandsaw. I don't need it but want it bad.

I think it would be a pleasure to use instead of the corded or 18v ones I have.
 
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Old Grumpy Bastard
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61,265 Posts
I'm not allowed to shop for tools without a chaperone. :laughing:
I wish my wife would say something, she always says "well if you want it".

Self control isn't that easy.

Thank God I realize I have too much already.
 

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Bilge Rat
motors and controls.........
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7,325 Posts
I have a BK Precision 307A megger. It's a basic analog type, 250, 500 and 1000VDC. It also has 3Ω and 500Ω resistance ranges.

It gets used once or twice a week, batteries last 6 months or so.

I like analog meggers more than digital ones, maybe it's just the old school in me......lol.

One of the more idiotic things I do with my megger is every time I change batteries, I get out my DMMs and 'megger' them. All of them will go up to 1000VDC, so I set them to read DC volts and blast them with 1000VDC. I figure is the internal electronics will stand 1000 VDC, it'll very likely stand 480 VAC too.

Yes, this is not a UL listed, OSHA approved MSHA required test but I cringe a bit every time I touch test leads to any system that has a fairly high incident energy level.
 

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Old Grumpy Bastard
Joined
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61,265 Posts
I have a BK Precision 307A megger. It's a basic analog type, 250, 500 and 1000VDC. It also has 3Ω and 500Ω resistance ranges.

It gets used once or twice a week, batteries last 6 months or so.

I like analog meggers more than digital ones, maybe it's just the old school in me......lol.

One of the more idiotic things I do with my megger is every time I change batteries, I get out my DMMs and 'megger' them. All of them will go up to 1000VDC, so I set them to read DC volts and blast them with 1000VDC. I figure is the internal electronics will stand 1000 VDC, it'll very likely stand 480 VAC too.

Yes, this is not a UL listed, OSHA approved MSHA required test but I cringe a bit every time I touch test leads to any system that has a fairly high incident energy level.

LOL, I do that as well. I will also retest if the readings are higher than I expect just to make sure.
 
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Discussion Starter #75
Maybe I'm just stating the obvious here ... but watch out for hardwired stuff in an existing house :eek: .
Alarm systems, door bell cct ... etc !


I've heard if you Meg with L and N connected together, to ground, that you won't see the magic smoke ... but I can't confirm

Maybe @brian john can comment.
Very true and electronics in switchboards, start at 100 VDC if you see a dead short or a very low reading investigate.

We were getting calls several weeks in a row on Sunday, after a competitor did maintenances on switchboards, we finally figured out there were begging the phase failure relays seems one particular brand would be damaged by this and would hold for a while then trip, hold for a while trip.

Why they called us and not the company that did the maintenance was another story.

I set a letter to my competitor telling him what was the issue.
 
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