While performing routine timing tests on a 15kv 1200 amp OCB, bot the close command test data and the open command test data was well within trending perimeters. But when performing a close/open command, ( simulating closing into a fault), all data came back 000.000 on ALL poles, and on both...
Looking for some seasoned advice on choosing a single conductor cable for a DC replacement project.
Cable will be 2/0 copper, will be in out door cable trench( exposed to weather) in conduit ( separate) , and also run inside in cable tray.
I have checked a few vendors ( Okonite etc)...And I...
Recently on our 72K Dead Tank( Alstom) SF6 CB's, we have been getting a rash of negative readings. We perform GST, GST (guard) and UST tests.
Some of our tests are coming back negative Pf, and negative watts. This has happened a couple of times in the past, and when tested a year later, the...
I have searched for like threads, but have not found anything current.
Based on the current CFR Title 40 dated February 12, 2012, if a transformer of sufficient size is located in an area that is miles from a navigable water source ( city area), would a SPCC still be sufficient?
The document...
Recently we received quite a few Cooper 997kva 7200-277 single phase transformers, for use in some of our larger customer subs. Some have been installed, and when IR scanned, they show excessive heat( 300f) right between the secondary bushings. In this exact area between the bushings, and on...
Recently a 15mva transformer at one of our small substations was sampled for DGA.
Our sample showed 6ppm for moisture in oil(D-1533B) and 7ppm for % saturation at top oil temp. The interfacial tension was 39.8
One week BEFORE, an outside testing company, using the same testing lab, sampled...
Does anyone have a suggestion regarding this..?
1590 acsr taps from 16kv isolation switch to bushing connectors at top of outdoor vacuum CB.
The old isolation switches have copper "pads", not tinned or bronzed. The 1590 lugs are all aluminum. The existing connection was made up with similar...
I work on a field crew for a small utility. You would be amazed at the different answers I get, when I ask, "How close do we need to match the impedance values, when banking transformers? "
I've seen substation transformers that seemed to have quite a difference, but Im talking regular...
