Old connections inspection

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mdshunk said:
... some insulation compromise was developing over time. The megger would have jumped out that compromised insulation and showed a bad reading before a genuine copper-to-steel ground fault developed. ...
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I didn't word my question very well. How are you going to meg the service side - isn't it sort of energized?

...Electrical testing, even if only visual, is a vital part of a building's overall maintenance program ...
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Yes, especially the visual part for some conditions.

carl
 
brian john said:
I'll post IR shots on Wednesday of taped connections faiing. On site Tuesday.
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Humm.. I'm not doing well at wording my questions.

Yes, I'm sure there is plenty IR evidence of tapped connections failing. However, nothing says the current carrying capacity of the joint was compromised, the tapped joint wore through the the tape rubbing on the sheetmetal. How do you find that with an IR scan?

carl
 
coulter said:
So you call the utility to come cut the leads every year to do the tests?
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I'm not totally convinced anything needs done on the wee service he shows as often as annually, but bigger services are certainly shut down every few years for testing and maintenance. Every two to every five would be pretty normal, in my experience, depending on who the insurance carrier is. That type of service doesn't really get "cut". They just pull some cutouts or pull an elbow.

Truth be told, very darned few services as small as the one for this store are ever checked beyond visually. They are normally conemned on a visual inspection only, and scheduled for replacement. Did you look at the pictures of this place? It was a dump.
 
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Can we possibly turn this into a poll? How many of you guys/gals utilize a thermal imager? They're not an inexpensive piece of test equipment by any means, but yet are priceless in the field!

What are you using, and what are your pro's and con's?
 
76nemo said:
Can we possibly turn this into a poll? How many of you guys/gals utilize a thermal imager? They're not an inexpensive piece of test equipment by any means, but yet are priceless in the field!

What are you using, and what are your pro's and con's?
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What, are you nuts? Not expensive? Compared to what? Even a cheap B-Cam is 4 or 5K, and the real deal is closer to 25K and they go much higher.

If you ask me, IR and insulation resistance checks are complimentart and not exclusive. They each have their weak points and strong points. You won't find a failed connection with an IR scan that presently has no load, for instance. A megger check can't be done on energized equipment.
 
Pierre C Belarge said:
One of the differences in Infrared vs Meggering is that the infrared can be performed without disconnecting the power, and at maximum load. I like meggering, but sometimes it is not possible to convince the customer to shut down for preventative/predictive maintenance.


I do not have the infrared camera, but the cost of the cameras is coming down where it will not be long before a contractor can make money using them, as the cost to provide the service will also come down.
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Pierre fluke sells an inexpensive laser thermometer under a hundred bucks which can be very helpfull in reading temperatures of things you dont want to touch or get close to. You can come up with the darndest uses for this too I used it last week to help an oil burner mechanic measure the discharge temp of the water to make sure it wasnt too hot to scald.
 
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