BX or MC metal-clad cable

…is better than Romex for your health.

Important Note: Before any new build, it is important to have your property tested for stray ground current and soil resistivity. For BX (metal-clad) wiring to be effective, you need a proper functioning ground system. If you do not have an adequate grounding connection to Earth, then metal-clad wiring will not improve your electromagnetic environment. It may even worsen your environment. So, if you already have metal-clad wiring, be sure to check the amperage and impedance on your ground rod.

The other day, I was consulting for a new home being built in Old Westbury, Long Island, New York. The home was recently framed and paneled, but the electrical was not yet installed.

In an email, the owner asked for some clarity on one recommendation. Here was my email response.

Yes. Yesterday, I mentioned that my dream is to build our family's home someday and install BX cable and fiber-optic light-pipe into the walls.

First, because BX cabling provides a metal-clad covering for the electrical wires and is grounded, your electrical fields can be many times lower than the flux of the electrical fields emitted by unshielded Romex cable.

In NYC, my epidermal voltage at room-center is typically 35 mV. In the suburbs, it ranges from 1500-3500 mV. This difference is significant.

An elevated skin voltage has been proven to stimulate the fight or flight response, causing the adrenal glands to release cortisol, adrenaline, and aldosterone. A persistently elevated skin voltage could cause a variety of issues.

Second, because BX provides a grounded metal sheath over the wiring, RF (radiofrequency or microwave radiation) will not couple onto the electrical wiring. This greatly reduces EMI (electromagnetic interference, A.K.A. dirty electricity) not only on the hot wire, the return neutral wire, but will also help prevent the ground wire from being corrupted. BX cable will not prevent EMI from forming on the hot wire completely because the power companies supply electricity between 200-700 mV of noise or harmonic transients.

Less EMI translates into a better function for all electronic devices, reduces the electric field size, and causes a minimal EMI coupled onto the indoor E and B fields.

The third is obvious: If any critters find themselves in the walls of your home (squirrels, field mice, etc.), they will not be able to bite through electrical cable because it is covered with metal-clad; helping to keep them from being electrocuted inside your walls, and preventing them from causing damage to the wiring which causes increased inductance and a potential fire.

BX cabling costs more to install, and some electricians may belly-ache about using it because it is heavier and slightly more cumbersome to work with, but if I were to build a new home, it would consider it essential.