The safety and reliability of all electrical systems is reliant upon maintaining good electrical connections - this includes both normal current-carrying connections and the grounding and bonding (normally non-current-carrying) connections. Virtually all of these connections are both mechanical and field installed and therefore subject to some installation variability. With current-carry conductor connections, if a splice or connection comes loose, there is typically immediate feedback in the form of a loss of power. With grounding and bonding connections, if a splice or connection comes loose, there is NO immediate feedback or indicator. Given that there are hundreds-to-thousands of field installed manual mechanical connections on a project, installation variability can impact some of these connections.
Field Tightened Ground Path Connections – EMT & Grounding Conductor
In a typical conduit (EMT) and wire installation, there are two primary ground paths: 1) green copper equipment grounding conductor and 2) EMT. The connection reliability of both of these ground paths is equally important and reliant upon each of the following manually tightened field connections per box and run of EMT:
Field Tightened Ground Path Connections – Interlocked Armor MC Cable
In a typical interlocked armor MC cable installation, there are two ground paths: 1) the primary ground path is the green copper equipment grounding conductor and 2) the interlocked armor which is part of the ground path but is not suitable to function as the ground by itself. The connection reliability of both of these ground paths is important and reliant upon each of the following manually tightened field connections per box:
MCAP Cable can Reduce or Eliminate Field Tightened Ground Path Connections
With MCAP cable, the armor and grounding/bonding conductor are combined such that they are in intimate contact throughout the entire cable length. This allows the interlocked armor to serve as the ground path for the cable, eliminates the need to terminate the grounding/bonding conductor inside a box or enclosure, and reduces the number of field tightened ground path connections "see Improved Grounding Performance". Additionally, the potential impact of installation variability can be further mitigated through the use of push-on snap-in style fittings, which do no require mechanical tightening of a locknut, a setscrew, or a screw cable clamp.
Virtually all the mechanical field tightened ground path connections can be eliminated which can mitigate installation variability.