Edwards AE Bulletin E-FSA Loop Wiring Ed

AEBN 102729 10 27 09 E FSA Addressable Loop Wiring B of the E FSA Technical Reference Manual part number 3101202 includes and charts for total wire and maximum wire distances for the addressable This bulletin will try and clear up some possible confusion and explain where the came from the addressable loop you have to be concerned with both the total wire connected to circuit including all t taps as well as the distance from the panel to the device away There are two primary components that go into figuring out wire Wire capacitance and wire resistance maximum amount of wire connected to loop The manual states you can have up to of total wire This is based on the maximum allowable loop capacitance rating 500,000pF divided by the cable capacitance rating 25pF ft for 14 AWG non shielded was used Capacitance in parallel is additive which is why you have to total up all t tap wire distances then you may ask if I don have any t taps does that mean I can go 20K feet a straight line The answer is no because the other part of the equation is wire The maximum allowable loop resistance is 66 ohms Typical resistance for AWG wire is 5.05 ohms per 1000ft pair 66 5.05 x 1000 13,069ft you look at Appendix B you see charts with various cable types and the distances can go on a fully loaded loop These distances are from the panel to the farthest assuming a class B loop Notice you do not see 20K feet anywhere You may wonder why we only show maxed out loops You think you could go farther with devices therefore less load Even with only one device on a loop using 14 AWG however you still limited to 13K feet because of the 66 ohms max loop copy of Appendix B follows for your reference 800 336 4206 Web www edwardssignaling com E mail signaling techsupport ge com Signaling 3 Farm Glen Blvd Farmington CT 06032 B Worksheets loop maximum wire length worksheet the instructions provided below to calculate the maximum wire for a device loop The maximum wire length is made up of components the total amount of wire and the longest circuit 1 Total wire the worksheet below to calculate the total amount of wire that can use to construct a device loop The total amount of wire is on the cable manufacturer s capacitance per foot rating In case shall the total amount of wire exceed the values listed in 1 capacitance wire 1 Maximum amount of wire you can use to construct a device loop type pair nonshielded pF 36 pF 38 pF pair shielded pF 82 pF 84 pF pair nonshielded pF 20 pF 20 pF 2 Longest path AWG or sq mm AWG or sq mm AWG or sq mm ft m ft m ft m ft m ft m ft m ft m ft m ft m Table 2 or Table 3 to determine the device loop longest circuit The longest circuit path is based on wire size and type and the of detectors and modules installed on the loop When using the tables to calculate a wire length for the 64 panel do not exceed a total of 64 device addresses any of detectors and modules the illustration below the longest circuit path shown in bold lines 1,240 ft 378 m The total amount of wire comprising the loop is ft 500 m and eFSA250 Technical Reference Manual B Worksheets circuit path diagram ft m ft m 2 Twisted shielded and nontwisted shielded ft m ft m ft m ft m ft m distributed distance loaded distance AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m and eFSA250 Technical Reference Manual 2 Twisted shielded and nontwisted shielded AWG distributed distance loaded distance B Worksheets ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m AWG ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m ft m AWG ft m ft m ft m ft m 3 Twisted nonshielded and nontwisted nonshielded distributed distance loaded distance and eFSA250 Technical Reference Manual