Tray Sizing Guide

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. The sum of the cross sectional areas of all cables cannot exceed 50% of the trays fill area. The cable tray sizing equals the width times the loading depth. Generally, cable tray sizing is correct when it appears 50% full of cable or wire , or when it contains a 50% fill of cables or wire.