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  1. teng22

    Debug in Compaq Visual Fortran ver. 6.6

    Hi I assume you are debugging a *.exe? If so then you should look at the messages returned in the command line window. On the first line you will see the reference to the cause of the problem ... examples : division by zero ... : square root of negative number.... : etc...
  2. teng22

    Aluminum Transformer windings-Areva Transformers

    I would be surpised if you have any problems with Areva T&D as they are certainly one of the major transformer manufacturers. As you rightly say, they were formerly part of the Alstom group and their UK division was previously GEC before that. For more information on this company you could try...
  3. teng22

    transformer rating

    As mnewman says, the current rating is based on the no-load voltage. You need to check the no-load voltage quoted on the transformer rating plate. Typically this will be 433 V so I would agree with mnewmans value of 2133 Amps as the rated current of this winding.
  4. teng22

    Unit-Substation Transformers Efficiency

    Clearly the efficiency depends upon the load and no-load loss characteristics of the transformer. As an estimation a 2.5 MVA 11/0.433kV transformer will have approximately 2.8 kW no-load loss & 21 kW load loss. Assuming these figues the maximum efficiency will be approximately 99.4% at unity...
  5. teng22

    12 pulse transformer secondary voltage difference

    Again for your interest.. The suggestion to use zig-zag (Zn) LV's with HV's having phase-shifted windings would increase the complexity and cost of the transformer. For the LV side you will still face the problem of a low number of turns, and you will introduce the additional problem of winding...
  6. teng22

    12 pulse transformer secondary voltage difference

    This maybe not a direct answer to your question, but it may help your understanding. For the 12 pulse rectifier transformer the first thing to realise is that there is a limited number of turns ratios that can be used. As one secondary will be Delta connected & the other Wye connected, the...
  7. teng22

    Array Declaration

    Perhaps this will help ... You can dimension an array using integer variables. these variables can be passed into your function or subroutine along with the value you want to assign As a very basic example:- SUBROUTINE DOTHIS(NARG,MARG,VALUE) DIMENSION MYARRAY(NARG,MARG) DO...
  8. teng22

    Books on transformer winding

    Large Power Transformers: Karsai, Kerényi & Kiss : Elsevier, 1987 : ISBN 0-444-99511-0 An excellent book!
  9. teng22

    Fortran Windows Application

    You could use VB to create the interface. The purpose of the interface being to create the input files needed to run your Fortran program. The Fortran program can be compiled as a *.dll to be called from your VB interface. Output files can be displayed directly in the VB interface. How? In...
  10. teng22

    Cna we compile VBA codes

    No But provide the original code author used true VB coding, rather than relying on VBA functions and commands then it is a relatively simple job to extract and compile the files directly using VB ... as the other respondant has already indicated.
  11. teng22

    X/R transformer calculations

    Many transformer rating plates show the tested load loss figures. This will be the value at the rated power and will have been corrected to a reference temperature, usually 75°C for IEC oil filled transformers. If the information is not on the rating plate it will certainly be available on the...
  12. teng22

    What is meant by a "yoke"?

    Large transformer cores are commonly defined in the following way: Legs = wound limbs = the section of core upon which the coils are mounted Yoke = the sections of core joining the wound limbs Normally' Legs can be considered to be the vertical parts and yokes the horizontally parts connecting...
  13. teng22

    Convection - Best Books

    You could try "Heat Transfer"; 7th ed ; J.P. Holman; McGraw-Hill; 1990 (I think it's on 8th ed now!) I have found this to be an excellent reference Regards
  14. teng22

    Allowable compression of unstiffened elements

    I agree with trainguy. I spend almost half day to derive the formulae for design upside-down T beam and another half day to run full finite element analysis to check my formulae. And,it is found that using upside-down T beam is not a good design at all...soory to be another downer
  15. teng22

    COMPOSITE JOIST DESIGN

    Hi, I am looking for a reference about composte joist design. I know how to design composite beam (composite action between slab concrete and I-shaped beam with shear stud), but I am not sure that the same concept can be used in case of open-web steel joist. Any good references to read...
  16. teng22

    Crushing of Composite Metal Deck

    Y ou can check web cripping (bearing) strength of deck to make sure you have enough bearing length. AISI specification and "COLD-FORMED STEEL DESIGN" by Prof. Wei-Wen Yu should be a good reference.
  17. teng22

    STABILITY ANALYSIS OF TRUSS

    I am designing very big double-pitched roof truss (6"per foot pitch, 20 feet deep at midspan, span length is 90'-0"). We can't build this in one piece. So we plan to build two trusses with 10'-0" deep each and splice them in the field. Does anyone have an idea how to check lateral...
  18. teng22

    Roof deck lateral buckling

    I think " steel deck diaphragm design manual" by Prof. Larry D. Luttrell would be a good reference. You can buy it from SDI. His research shows that compressive strength of deck is controlled by local buckling at each flute, and he develop some kind of eqivalent spring concept to...

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