{ "metadata": { "name": "", "signature": "sha256:45b10dfe17575c3ed7a29e1acbc44a49a10b5cd350f1c1220204785620825edf" }, "nbformat": 3, "nbformat_minor": 0, "worksheets": [ { "cells": [ { "cell_type": "heading", "level": 1, "metadata": {}, "source": [ "Chapter 2 : Transmission Line Structures and Equipment" ] }, { "cell_type": "heading", "level": 2, "metadata": {}, "source": [ "Example 2.1 Page No : 77" ] }, { "cell_type": "code", "collapsed": false, "input": [ "import math \n", "\n", "# GIVEN DATA\n", "t_s = 0.49 ; # Human body is in contact with 60 Hz power for 0.49 sec\n", "r = 100 ; # Resistivity of soil based on IEEE std 80-2000 \n", "\n", "# CALCULATIONS\n", "# For case (a)\n", "v_touch50 = 0.116*(1000+1.5*r)/math.sqrt(t_s) ; # Maximum allowable touch voltage for 50 kg body weight in volts\n", "\n", "# For case (b)\n", "v_step50 = 0.116*(1000+6*r)/math.sqrt(t_s) ; # Maximum allowable step voltage for 50 kg body weight in volts\n", "# Above Equations of case (a) & (b) applicable if no protective surface layer is used\n", "\n", "# For metal to metal contact below equation holds good . Hence resistivity is zero\n", "r_1 = 0 ; # Resistivity is zero\n", "\n", "# For case (c)\n", "v_mm_touch50 = 0.116*(1000)/math.sqrt(t_s) ; # Maximum allowable touch voltage for 50 kg body weight in volts for metal to metal contact\n", "\n", "# For case (d)\n", "v_mm_touch70 = 0.157*(1000)/math.sqrt(t_s) ; # Maximum allowable touch voltage for 70 kg body weight in volts for metal to metal contact\n", "\n", "# DISPLAY RESULTS\n", "print \" a) Tolerable Touch potential , V_touch50 = %.f V , for 50 kg body weight \"%(v_touch50) ;\n", "print \" b) Tolerable Step potential , V_step50 = %.f V , for 50 kg body weight \"%(v_step50) ;\n", "print \" c) Tolerable Touch Voltage for metal-to-metal contact , V_mm_touch50 = %.1f V , for 50 kg body weight \"%(v_mm_touch50) ;\n", "print \" d) Tolerable Touch Voltage for metal-to-metal contact , V_mm_touch70 = %.1f V , for 70 kg body weight \"%(v_mm_touch70) ;\n" ], "language": "python", "metadata": {}, "outputs": [ { "output_type": "stream", "stream": "stdout", "text": [ " a) Tolerable Touch potential , V_touch50 = 191 V , for 50 kg body weight \n", " b) Tolerable Step potential , V_step50 = 265 V , for 50 kg body weight \n", " c) Tolerable Touch Voltage for metal-to-metal contact , V_mm_touch50 = 165.7 V , for 50 kg body weight \n", " d) Tolerable Touch Voltage for metal-to-metal contact , V_mm_touch70 = 224.3 V , for 70 kg body weight \n" ] } ], "prompt_number": 1 } ], "metadata": {} } ] }