On new installations of cable, our utility still requires a DC hi pot "proof" test, to what ever voltage the chart says. Our primary cable is EPR.
This engineer wanted us to " meg " the cable, using a our Biddle 15kv meggar. I disagreed.
I was looking for opinions on why he might want the...
Thats my point, wareagle.
I was told by an engineer to Megg a new installation of cable. I just dont understand what he was looking for from this sort of test.
I have always DC highpotted a new cable installation, to most of the time, ATLEAST twice the rating of the cable.
HP
What REALLY would this prove? This is shieled, jacketed 15kv cable, 3 conductors per conduit. The "run" is approx. 1000' long, with pole top terminations at each end.
HP
thanks everyone.
Wow, Waross, those links are great. I'll check them all out.
I can't see how just soldering this bus would be sufficient. But since you say the solder is actually stronger then the copper, I guess Im wrong. I am partial to a bolt together system, if rated properly...
We have some 3000amp rated, tubular copper bus work. Any suggestion on a good way to cut out a ssection, then put it back in? A splice you might say, between tubular, 3"square x 1/4" thick copper bus.
Can copper bus be "welded" ? If so, what would be the best way? Or should "splice plates" be...
The AC dip was for slightly more then 50 cycles. The DC dip was only for 10 cycles.
The bank was just recently tested and all was good. It was not however discharge tested or load tested.
Have any of you heard of the term " Coup De Fouet "
HP
We have a bank of lead acid batteries providing substation dc power.
Recently, during an event, we had a dip in our station power, which of course caused a dip on the input voltage to the charger.
At the exact same time the station power dipped, our DC voltage dipped from 134v to 78v, but for...
I am being asked to calculate, then mark(identify) 4 different locations, on a customers electrical infrastructure. Very simple installation. Small 3 phase service provided by the power company, then feeding several loads thruout the companies property.
Is there software/info available where...
Thanks for your responses. In this case, the Troubleman marked the rotation prior to deenergizing the service, and then a different meter was used when checking before renergizing.
Next time, the same meter will be used, regardless.
HP
Is this possible? CustomersElectrical service is to be replaced.
One type of rotation meter is used to mark rotation on the 480v 3 phase service. Phasing is marked " blue-white-red " Clockwise rotation
After customer service is replaced, the service is energized to the meter and checked with...
moisture content -- 7ppm
interfacial tension-- 47.9
Electricpete,
How long would the sample have to be subjected to sunlight? Hours? days?
Our bottles are clear as well as our glass syringes.
thanks for everyones opinions
hp
To all that have chimed in, thanks for your thoughts. I learn so much at this site.
I do not have the data with me at home, but here are some answers off the top of my head.
The transformer is NOT a GSU
The transformer is sealed nitrogen
The transformer is approx. 24 years old
The...
Here is an example of the latest testing for the transformer in question (15mva 66/7kv)
hydrogen: 0
methane: 45
ethane: 17
ethylene: 2
acetylene: 0
carbon monoxide: 728
carbon dioxide: 28900
And here are the results from 6 months ago...
hydrogen: 0
methane: 55
ethane: 23
ethylene: 4...
We have several transformers that come back from lab testing with high carbon dioxide levels. ( over 10,000 )
Now, we have a small wager on this....
Can the "manner" in which you take the oil sample, substantialy effect the outcome of the test regarding carbon dioxide?
HP
