I installed Mathcad 15 m1010 in Windows 7 and later upgraded to Windows 10 and it ran fine under Windows 10 for a year or so. Unrelated to Mathcad, Windows 10 recently developed explorer issues, faulting every few minutes and restarting. Tried everything finally solving the issue by clean...
I upgraded from Windows XP to Windows 7 and at the same time moved from MathCad 14 to MathCad 15 to ensure compatibility with Windows 7 and in the hope of a gaining few bug fixes, otherwise MCAD 15 seems to me to be identical to Mcad 14. I went on the Flexnet license server on the PTC website...
Folks:
We have a project at substation where the transformer have delta secondary windings. The windings supply metal clad switchgear through U/G cable (PILC would be my guess by observation). The metal clad supplies a 13.8 kV distribution system. There is no sign of a grounding reactor at the...
Gentlemen: We have a substation with uses six distribution transformers as bus potential VTs supplying protection, SCADA and revenue metering. The name plates have faded in with time and are nearly illegible. We cannot make out the model number but we can read some data stamped into the metal...
Folks: I have a set of bushing CTs that could be used for revenue metering if previously approved by the regulator.
The name plate says they are type BYM part number 72-281-240-011 manufactured by Siemans Power T&D, inc.
The regulator has posted approval for type BYM style 72281240011 (same...
I have a very complete set of factory test records for a three phase, three winding transformer, stepping tansmission voltage down to distribution voltage. There are four load-loss tests in the test pages, each recording impedance voltage and kW loss.
The factory carried out the usual H-X...
Folks:
We have just installed metering on a 46kV class subtransmission line with vertical configuration. We assumed the phase layout was A-B-C top to bottom but it turned out to be B-C-A. There is no neutral so we used two element metering, connecting the VT primaries B-C and A-C making the...
Folks:
ANSI has defined a number of standard burdens (W,X,Y,Z,ZZ and sometimes M). Usually a VT nameplate will list all that it can support e.g. 0.3WXY for a 75 VA unit and 0.3WXYZ for a 200 VA unit.
But what does it mean if the name plate on a VT with one secondary lists only one value...
Folks:
I've got metering at the wrong end of some direct buried concentric neutral XPLE cable, three single phase cables, 1000MCM Cu with 1/3 neutral, XLPE, grounded both ends.
I need to correct for losses. The load is well balanced so I am focusing on positive sequence current.
When I look...
I am doing a burden study for a revenue meter installation that must include an ancient GE MC65 phase shifter used to convert a watt transducer into a var transducer. I have suggested replacing it but the client has declined.
Would anyone know where I could find out what burden the phase...
The IEEE Standard 1459-2000, section 3.1.1.3 defines reactive power as the contour integral of v*di divided by 2*PI. Does anyone know the origins of this definition?
Sometimes records of factory test results for a three winding power transformer are only partially complete. Often the other results are available but the kW figures for the X-Y test are missing . A local rule of thumb that seems to have emerged is:
kW loss X-Y = 0.85 *(kW loss H-X + kW...
Folks:
I have a three winding transformer, DYY, and need to do some load flow calculations. The T&D book and Blackburn show how to convert the factory test results on winding pairs H-X, H-Y and X-Y into an equivalent Y configuration that can then be analysed. But the factory test report shows...
