Let's assume I'm wiring a house with ethernet cables. Cables will be bundled together and each bundle will be wrapped in a sleeve to protect cables from rodents (amongst other benefits). Sleeves come in predefined inner diameters, e.g. 1/8", 1/4", 3/8" and so forth. While ethernet cables can be measured as 22 AWG to 28 AWG, external diameter may vary due to its cable jacket.
Let's assume I have a bundle consisting of 6 cables with a max diameter of 4mm. The 4mm may include a protective sleeve. My understanding is that given the diameter of a single cable, I can calculate its area.
var cableDiameter = 4; var cableArea = ((cableDiameter * cableDiameter) * Math.PI) / 4;
To get the area of the bundle of cables, I can multiply it by the number of cables:
var cableCount = 6; var bundleArea = cableArea * cableCount;
And then what's left if to calculate the diameter of the bundle:
var bundleDiameter = Math.Sqrt((bundleArea * 4)/ Math.PI);
I can then convert that to inches.
var inch = 25.4; var bundleDiameterInches = Math.Round(bundleDiameter / inch, 2);
Which gives me a 9.8mm or 0.39” for the diameter of the bundle consisting of six cables with a diameter of 4mm (28 AWG), which implies I can use a sleeve with an inner diameter of 3/8” provided it can stretch to 0.39". For a bundle consisting of 6.5mm cables (24 AWG), a sleeve with an inner diameter of 5/8” or 3/4” may suffice.
But it seems my calculations may be a bit too optimistic. It doesn't include room for cables to flex when the bundle of cables are bent. I also read that other factors of the cable, such as heat and interference, may require additional spacing around each cable.
What other factors should be taken into account when calculating the diameter of a bundle of cables for wrapping them in a sleeve?