Cable Tray Sizes Calculation

Here voltage drop for 70 sq mm cable 5 8 is higher than define voltage drop 5 so either select higher size of cable or increase no of cable runs.

Cable tray sizes calculation.

Conduit fill calculator conduit fill is the percent of area inside the conduit taken up by the cable s. It is recommended not to exceed a voltage drop of 5. Distance enter the one way length of the wires in the circuit in feet. Cable tray should be perforated and 20 spare capacity.

Cable tray is sized based on the number and type of cables required for the current and future need. Cable id cable o d. Voltage drop choose the maximum percentage of the source voltage drop. Distance between each cable is 10mm.

Ii no of cables more than 2100 v in the cable tray. Iii no of single conductor cables 2000 volts in the cable tray nec 392 12. The cable sizing calculator considers solid or stranded copper conductors only. Not required outside diameter cable qty cable size weight lbs ft total cable weight.

A 50 fill ratio should equal the maximum number of cables pulled in a given cross section. Per the national electrical code article nema 392 9 b cable tray fill calculations and cable tray sizing calculations will be computed as follows. 2 fill in all pertinent project information. It is based on cable type insulation type and the cable installation method.

Tables 4 to 21 are based on an ambient temperature of 40 c and a ground temperature of 25 c. 9 to begin a new calculation return to the input screen and select the clear button. Lbs ft inside tray depth. Minimum allowable tray.

Cable raceway tray support calculations. The current ratings are selected from tables 4 to 21 in as nzs 3008. On tue dec 2 2014 at 7 52 pm electrical notes articles wrote. This is typically in a raceway cable tray or conduit in a cable burried in the earth or in open air.

Provides quick and easy results for the conduit fill percent per nec guidelines. Cable trays may be filled 50 when using control or signal wiring. If we select 2 runs than voltage drop is 2 8 which is within limit 5 but to use 2 runs of cable of 70 sq mm cable is not economical so it s necessary to use next higher size of cable. The sum of the cross sectional areas of all cables cannot exceed 50 of the trays fill area.

Solid bottom cable tray when using solid bottom cable tray the allowable cable area is reduced from 50 to 40. The sum of the diameters of all cables rated 2001 volts or over is not to exceed the cable tray width. 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. Cable are laying in single layer in cable tray.