SystemQ Posted June 20, 2006 Share Posted June 20, 2006 Cqr state 92 Ohms per KM at 20 CelsiusYou System Q Ltd. Link to comment https://www.thesecurityinstaller.co.uk/community/topic/11037-how-do-i-work-out-volts-drop/page/2/#findComment-103906 Share on other sites More sharing options...
Guest Posted June 20, 2006 Share Posted June 20, 2006 Cqr state 92 Ohms per KM at 20 CelsiusYou Link to comment https://www.thesecurityinstaller.co.uk/community/topic/11037-how-do-i-work-out-volts-drop/page/2/#findComment-103907 Share on other sites More sharing options...
Guest Posted June 20, 2006 Share Posted June 20, 2006 It is the resistance of a pair that will give you the voltage drop. no a single core give the same results using my method compare the tables 100ma over 100M (7 / 0.2) there within a few % of each other Your paired method must work by having twice the resistance but half the cable length? Whether we would get the same results through out the table?? Don Link to comment https://www.thesecurityinstaller.co.uk/community/topic/11037-how-do-i-work-out-volts-drop/page/2/#findComment-103912 Share on other sites More sharing options...
Truss and France Posted June 20, 2006 Share Posted June 20, 2006 Love it! Link to comment https://www.thesecurityinstaller.co.uk/community/topic/11037-how-do-i-work-out-volts-drop/page/2/#findComment-103921 Share on other sites More sharing options...
SystemQ Posted June 20, 2006 Share Posted June 20, 2006 no a single core give the same results using my methodcompare the tables 100ma over 100M (7 / 0.2) there within a few % of each other Your paired method must work by having twice the resistance but half the cable length? Whether we would get the same results through out the table?? Don System Q Ltd. Link to comment https://www.thesecurityinstaller.co.uk/community/topic/11037-how-do-i-work-out-volts-drop/page/2/#findComment-103923 Share on other sites More sharing options...
Guest Posted June 20, 2006 Share Posted June 20, 2006 0,00178 * 1000 / ( 0,25 x 0,25 x pi ) = 9,065 ohms ( ! one core - end to end ! )0,535 ohm difference most propably is caused by meter leads and two contact surfaces and meter inaccuracy.. edit: plus i expected CQR to be 0,5mm core diameter and i seem to have decimal mistake somewhere - which propably is in copper resistance per metre @ 1mm2... Link to comment https://www.thesecurityinstaller.co.uk/community/topic/11037-how-do-i-work-out-volts-drop/page/2/#findComment-103927 Share on other sites More sharing options...
esp-protocol Posted June 20, 2006 Share Posted June 20, 2006 Try this posted previously. Link to comment https://www.thesecurityinstaller.co.uk/community/topic/11037-how-do-i-work-out-volts-drop/page/2/#findComment-103943 Share on other sites More sharing options...
Guest Posted June 20, 2006 Share Posted June 20, 2006 2LRI = Volt DropWhere: L is the length of cable in meters R is the resistance per meter of the cable (see table above) in ohms I is the maximum current in Amps (Rcore) x (l x 2) x Iwhere: Rcore = resistivity of the cable per one metre l = length of the cable 2 = 2 I = current ( U/R ) or (V/R there at the island) i notice some similarities... drop = A x cable lenght x 0.08 x 2 but only now i got this.. was wondering for a long time from where did you get that 0.08 and A (was expecting I for amperes..) Link to comment https://www.thesecurityinstaller.co.uk/community/topic/11037-how-do-i-work-out-volts-drop/page/2/#findComment-103947 Share on other sites More sharing options...
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