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FREQUENTLY ASKED QUESTIONS
- What is the voltage of mainline power distribution and can HDPE conduit handle that voltage?
- How many cables can I fit into an innerduct or conduit?
What is the voltage of mainline power distribution and can HDPE conduit handle that voltage?HDPE conduits up to 8" in diameter have had solid dielectric, high voltage cables, rated at 345kV installed inside them. Further, conduit pipes through 6" are commonly used to protect underground distribution cables having voltage ratings from 600V to 35kV. Cable voltage ratings have not been a deterrent for utilities choosing to use conduit made from HDPE for underground power cables.
How many cables can I fit into an innerduct or conduit?It depends on the size and quantity of the cable. The NEC (National Electric Code) has guidelines on the number of conductors allowed in a HDPE Conduit. With one conductor, it can "fill" 53% of the inside diameter of the conduit. For 2 wires 31% and over 2 wires 40% fill ratio is allowed. Simply multiply the area of the conductors by the quantity and compare to the inside area of the pipe. The same general rules apply for fiber optic cable.