| 摘要 |
<p>A METHOD OF CHECKING THE CONDITION OF ELECTRICITY SUPPLY AND RETURN LINE CONDUCTORS IN A CONSUMER?S SUPPLIED PREMISES COMPRISING THE STEPS OF: MEASURING A SUPPLY VOLTAGE ACROSS THE ACTIVE AND NEUTRAL OR EARTH CONDUCTORS (14, 16A) AT A PREDETERMINED TIME. MEASURING THE SUPPLY VOLTAGE ACROSS THE ACTIVE AND NEUTRAL OR EARTH CONDUCTORS (14, 16A) AFTER A SWITCHING EVENT. DETERMINING THE LOOP IMPEDANCE AT THE CONSUMER?S PREMISES USING THE VOLTAGE MEASURED AT THE PREDETERMINED TIME AND AFTER THE SWITCHING EVENT. AND USING THE VALUE OF THE DETERMINED LOOP IMPEDANCE TO INDICATE THE CONDITION OF THE SUPPLY AND RETURN LINE CONDUCTORS. THE DETERMINATION OF THE LOOP IMPEDANCE INVOLVES USING THE RATIO OF THE VOLTAGE MEASURED AT THE PREDETERMINED TIME AND AFTER THE SWITCHING EVENT, AND USING A KNOWN VALUE OF THE IMPEDANCE INVOLVED IN THE SWITCHING EVENT. ALTERNATIVELY, THE DETERMINATION OF THE LOOP IMPEDANCE MAY ALSO INVOLVE: MEASURING THE CURRENT IN THE ACTIVE CONDUCTOR (14) AT THE PREDETERMINED TIME. MEASURING THE CURRENT IN THE ACTIVE CONDUCTOR (14) AFTER A SWITCHING EVENT. AND, DETERMINING THE LOOP IMPEDANCE AT THE CONSUMER?S PREMISES FROM THE RATIO OF: THE DIFFERENCE BETWEEN THE VOLTAGE MEASURED AT THE PREDETERMINED TIME AND AFTER THE SWITCHING EVENT. AND THE DIFFERENCE BETWEEN THE CURRENT MEASURED AT THE PREDETERMINED TIME AND AFTER THE SWITCHING EVENT. THE MOST ILLUSTRATIVE DRAWING IS</p> |
