Special Guidelines for LSF insulated / sheathed cables LSF (low smoke & fume) insulation / sheath does not have the same mechanical strength as other insulation / sheath material, particularly at higher temperatures. It is therefore recommended that LSF insulated/sheathed cables should be used mainly indoors, and only where cables have been specified to have low smoke and toxic gas emission property. Installation We recommend the following special guidelines, in conjunction with the standard installation instructions. The cables should be stored in proper packed condition, in shade and direct exposure to sun should be avoided. As LSF has lower tear strength property as compared to PVC/PE sheath, special care should be taken during installation to avoid any damage. Even a small cut on the LSF insulation/sheath will result in sheath cracking, as it will run in longitudinal direction due to lower tear strength property of LSF insulation/sheath. Use pay in rollers and corner rollers of non-metallic material (Nylon or Teflon) at least every 3 to 4 meters while laying the cable. As far as possible installation should be undercover or indoors. For outdoor installation, direct exposure
to sunlight should be avoided by using a suitable cable tray. The cables should not be in contact with any hot surface. The requirement of minimum bending radius should be followed as per data sheet.
Any clamping device should not be applied directly on the outer sheath. There should be some cushion (for instance a rubber pad of approx. 3 mm thickness) between the cable’s outer surface and clamps. Maximum distance of unsupported length of cable for horizontal and vertical run should be as below:
Overall diameter of cable (mm)
Max. spacing between the supports for horizontal run (mm)
Max. spacing between the supports for vertical run (mm)
0-14.9
350
450
15-19.9
400
550
20-39.9
450
600
40-59.9
700
900
60 & above
1100
1300
Re-winding In case re-winding should be necessary, extreme caution should be taken during the process to avoid damage The following should be adhered to: The winding should be done equally and uniformly with no over-riding of the coils or pinching on the sides of the drum. The pay-off drum should have an adequate braking system to prevent the cable from coming loose on the drum.
17 MKXXS001-04/01-08-2015
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