Decoupling Power Cable Sheaths/Casings

Problem

Pipe-type power cables require effective grounding to protect your personnel and equipment from AC fault current. Any metal casings or lead sheaths that are cathodically protected will also need to be grounded, which can reduce CP values if they are directly connected.

Underground pipe-type cabling, if located near DC rail systems in an urban setting, can also carry nuisance voltage from passing trains. This extra DC voltage requires a decoupler that is rated to block higher levels of voltage and not short into conduction mode.

Solution

Dairyland’s Isolator/Surge Protector (ISP) is the ideal device for protecting pipe-type power cabling, given its higher DC blocking threshold and AC fault ratings. Stray nuisance voltage from overhead trains can be isolated at higher levels than other decoupler threshold ratings, preventing unnecessary grounding from slightly higher DC levels.

Installing the ISP in series with the lead sheathing or metal casing will also provide efficient isolation of CP voltage levels by decoupling the cable from the grounding grid. Higher AC fault current ratings and a fail-safe design will ensure that the ISP will protect personnel and equipment from potential fault events.