Recent content by Millbo

Refer to IEEE C37.2 - Standard for Electrical Power System Device Function Numbers, Acronyms, and Contact Designations

I think "cross load" is lateral load.

SCERS, The Megger publication, A stitch in Time" states the following: "...Acceptable insulation resistance values for dry and compound-filled transformers should be comparable to those for Class A rotating machinery, although no standard minimum values are available...." IEEE Standard 43...

The manufacturers O&M manual will give guidance on putting their units in long term storage. A few key things from memory: Keep the bushings/windings shorted and grounded If it's a conservator type unit keep up with the condition of the desiccant in its breather Power up the heaters in the...

Often due to head room and load weight most rigging contractors will use what's call "Jack & Slide" to move a load. This is where they will jack it up high enough to put rails under it then they will push it along those rails with hydraulic jacks. The better systems have catch pawls that the...

Thanks itsmoked. So does this mean its a modified wave signal?

VE1BLL, That current source sounds like it will fit the bill. I'll send them an email for some additional information. I appreciate the link and the leg work on this one, Mike Also, I also ran across a company called Lectrotek out of India. http://lectrotek.com They carry a device called...

This will need to be something that is both rugged and can survive field conditions. They will be hauled around in our test trucks with the other test equipment. I've exhausted every avenue I can think of. Thanks all and have a great holiday weekend, Mike

electricpete, A secondary current injection set is what I use to apply my test current to the circuit in my first reply. I remove the CT from the circuit and am just simulating the secondary of that CT as if the transformer was at full load. I chose to use these injection sets being they...

VE1BLL Thanks for the replay but I may have been a little vauge in my initial post. The bushing CT that I'm simulating the secondary current for is installed inside the transformer and I don't really need access to it. I'm just simulating it's output current. To perform the commissioning test I...

I also agree with ppedUK and jkristinn How sudden did this condition come on? Are loads and temperatures logged on a regular basis? These values will allow you to plot out any trends. One suggestion I have it to look at your cooling system thru an IR camera while the unit is loaded and check...

I have a question or perhaps more of request for information and or suggestions please from those who know electronics more than I do. My Issue at hand: I need an adjustable constant AC current source to simulate the secondary of an energized hotspot CT to verify the winding temperature...

I'm partial to the Baron units. We have eight of their HV-1800 models and their performance is great.

The wrong test connections were used according to the transformers nameplate. Per the phasor diagram the test connections should have been: H1 - H3 = A phase H2 - H1 = B phase H3 - H2 = C phase The contractor followed the standard Doble template with those connection resulting in: H1 - H2...

1. I also agree with the general consensus. "Megger" that one floating bushing against ground to see what it's value is. Any Core ground or Frame (clamp) ground that is brought out should go to earth. If it was left open due to an inadvertent ground then that bushing should still go to...