PANDUIT: Electrical Full Line

ELECTRICAL SOLUTIONS C1.46 B2. Cable Accessories C1. Wiring Duct C3. Abrasion Protection C4. Cable Management D1. Terminals D2. Power Connectors E1. Labeling Systems E2. Labels E3. Pre-Printed & Write-On Markers F. Index B3. Stainless Steel Ties C2. Surface Raceway E5. Lockout/ Tagout & Safety Solutions B1. Cable Ties A. System Overview D3. Grounding Connectors E4. Permanent Identification Wirefill Formula General Formula Panduit Wiring Duct wirefills are calculated using the following general formula: Why use a 50%Wirefill? As specified in NFPA79-2007 section 13.5.2, Percentage Fills of Raceways (Ducts), a 50% wirefill is given as the maximum wirefill capacity in all Panduit Wiring Ducts. This helps ensure general safe wiring practices are followed. In actual practice, a 50% wirefill is the maximum amount of wiring the duct can hold given the additional airspace created between cables by non-uniform cable shapes, cable interlacing, and cable packing factors. Since we use the outer channel dimensions in our calculation, we make an adjustment in our formula for the thickness of material and for design elements that extend inside the channel. In our wirefill formula an adjustment is made to the channel internal area to account for “unusable” air space that will be present between cables when placed in the channel. Our formula assumes a uniform close packed or high-density cable arrangement (see diagram) (Note 1). What is the Usable Duct Area? The usable area we define as the calculation of internal area that can be occupied by wires or cables. Wire Area The wire area formula is converted to allow calculation using the cable diameter: Formula Derivation Inserting the elements from above into the general formula results in the following: Note: When calculating wirefill capacity using the above formula, variables W, H, and D must be expressed in same units (i.e. mm or inches). 1 This calculation does not account for additional airspace created between cables by non-uniform cable shapes, cable interlacing, and cable packing factors. 2 The resulting formula is used for all Panduit flush cover ducts, this excludes type NE duct which has a different profile design that results in a divisor of 2.0 x D 2 (rather than 1.75 x D 2 as shown here) and type H and HS wiring duct with a profile design that results in a divisor of 1.85 x D 2 and corner wiring duct which uses calculated internal area and a divisor of 2.0 x D 2 . Simplifying this formula results in the formula used for wirefill calculation (Note 2): Considering these factors, the usable duct area is equal to an average of 90% of the nominal area, or (W x H) x .90. Calculation of Internal Area Air Space Allotment