Cable Tray Size Calculation

This is typically in a raceway cable tray or conduit in a cable burried in the earth or in open air.

Cable tray size calculation.

Cable tray is sized based on the number and type of cables required for the current and future need. Per the national electrical code article nema 392 9 b cable tray fill calculations and cable tray sizing calculations will be computed as follows. Cable trays may be filled 50 when using control or signal wiring. Cable tray should be perforated and 20 spare capacity.

A 50 fill ratio should equal the maximum number of cables pulled in a given cross section. Voltage drop choose the maximum percentage of the source voltage drop. December 2 2014 at 3 38 pm. An example how to calculate voltage drop and size of electrical cable photo credit.

6 once all cable information is entered hit calculate. Calculate size of cable tray for following cable schedule. What is cable tray used for. The sum of the cross sectional areas of all cables cannot exceed 50 of the trays fill area.

On tue dec 2 2014 at 7 52 pm electrical notes articles wrote. Cable is directed buried in ground in trench at the depth of 1 meter ground temperature is approximate 35 deg. Ignore the neutral and earth conductor in three phase cables. Chart is based on 50 fill of 4 utp category 6 cable o d 21 033lbs ft not maximum loading weight for the tray.

Distance between each cable is 10mm. 1 2 no s of 3 5cx300 sq mm xlpe cable having 59 7mm outer diameter and 5 9 kg meter weight 2 2 no s of 3 5cx400 sq mm. The number of cores in the cable. It is recommended not to exceed a voltage drop of 5.

Select a cable size or select auto. Auto will automatically select the smallest cable that meets the three criteria for current rating voltage drop and fault current rating. Cable are laying in single layer in cable tray. Number of cable per trench is 1 number of run of cable is 1 run.

Cable tray is a bridge that allows safe transport of wires across open areas and gives protection against the overheating and fire problems. 7 once the calculate button has been selected the program will take you to the output page where the tray size needed will be displayed as well as the article of the nec that it falls under. Distance enter the one way length of the wires in the circuit in feet. Download cable tray and conduit sizing excel sheet free calculator for electrical design engineers to determine the size of cable tray and the wire conduits.