Why is sand filling required inside a concrete cable trench ?
Why is sand filling required inside a concrete cable trench ?
(OP)
As I understand , for directly buried cables , a layer of sand is provided before laying , and another layer is provided after laying for protection. However if I lay the cable inside underground concrete cable trench on cable trays , is it still required to fill the cable trench with sand. Does this requirement of sand filling change if the cable trench is passing through a hazardous area .






RE: Why is sand filling required inside a concrete cable trench ?
RE: Why is sand filling required inside a concrete cable trench ?
RE: Why is sand filling required inside a concrete cable trench ?
RE: Why is sand filling required inside a concrete cable trench ?
RE: Why is sand filling required inside a concrete cable trench ?
I am not arguing with the intent behind the practice . My only query is that what it should be as per international standards.
RE: Why is sand filling required inside a concrete cable trench ?
RE: Why is sand filling required inside a concrete cable trench ?
RE: Why is sand filling required inside a concrete cable trench ?
easierless difficult to deal with repair or adding new cables compared with breaking out 8" - 12" of reinforced concrete apron to expose the route. It has the further benefit that you actually know where the cables are rather than just having an idea of where they are.RE: Why is sand filling required inside a concrete cable trench ?
13.5.2.4.2 Electrical power, control, and instrument cabling required for safe shutdown of critical equipment during emergency plant shutdown should be routed outside the fire area. If routed through the fire area, it should be protected with fireproofing material in accordance with API Publication 2218, Fireproofing Practices in Petroleum and Petrochemical Processing.
API Publication 2218:
6.1.8.1 Electrical Power and Instrument Cable
a. Burying cable below grade. [it could be considered sand filled trench also?]
3. The use of cable tray systems designed to protect the cables from fire.
c. Cable trays encased with calcium silicate insulating panels with calcium silicate sleepers to hold cables away from bottom of the cable tray.
Anyway it is no mention of cable tray in sand filled trench.
RE: Why is sand filling required inside a concrete cable trench ?