Bx Wiring: Safe Or Not?

BX wiring is generally considered safer than knob-and-tube wiring, which is an older method of electrical wiring that can be unreliable and prone to fraying and deterioration. However, BX wiring does have some issues, such as being ungrounded and having cloth insulation that can break down over time, exposing bare copper. While some insurance companies may not offer coverage for homes with older wiring types like knob-and-tube or aluminium wiring, it is unclear whether BX wiring specifically is considered unsafe to insurance carriers.

BX wiring is safer than knob-and-tube wiring

Secondly, knob-and-tube wiring lacks a ground wire, which is essential for safely diverting excess electricity. While BX wiring also lacks a ground wire, its metal exterior sheathing can sometimes act as a ground. However, this is not reliable as it requires all connections to be tight, and any loose connections can lead to dangerous situations where the circuit breaker fails to trip.

Thirdly, knob-and-tube wiring uses rubber-based insulation around its conductors, which can become brittle and crumble when exposed to heat from light fixtures. BX wiring uses similar insulation, but since it is run through light boxes with multiple wires, it is less likely to be exposed to high levels of heat.

Finally, knob-and-tube wiring is often not covered by homeowners' insurance due to its known issues and increased risk of fire. In contrast, BX wiring does not typically have the same insurance issues, although it may still be quite old and in need of replacement.

Overall, while both types of wiring have their downsides, BX wiring is generally considered safer than knob-and-tube wiring due to its ability to accommodate insulation, its potential for grounding through the metal sheathing, its reduced exposure to heat, and its more favourable insurance coverage.

BX wiring is the second generation of wiring used in homes

BX wiring, also known as armoured cable, is the second generation of wiring used in homes. It first appeared in the 1903 National Electrical Code (NEC) book and was used until the late 1940s when it was replaced by early Romex (non-metallic sheathed cable). It became popular in the 1920s and was the main wiring type by 1932.

BX wiring is a type of metal-clad electrical cable that has been a popular choice for homeowners in the past due to its durability and added protection. It comprises plastic-coated insulated wires (usually 12- or 14-gauge) rolled up together and protected by a ribbon-like metal sheathing. The metal sheathing runs around the wires in a twisted or helix-like manner.

BX wiring is contrasted with newer non-metallic (NM) cables, such as the popular Romex brand, which has a slick vinyl covering, making it easier to rip and pull through holes in studs. Many homeowners prefer NM cables because they are lightweight, easy to handle, and affordable. However, BX wiring has unique benefits that make it a more suitable choice than NM cables in certain situations. For example, BX wiring is safer and protects against any accidental penetrations.

BX wiring relies on the outer coverings to maintain a ground path. Each time a BX wiring circuit goes in and out of a box, it uses a special connector with a lock nut. This lock nut and connector must be tight; otherwise, the circuit will lose its ground path. This becomes a safety hazard if there is a short circuit to ground, as the breaker/fuse may not trip because the ground path is no good.

BX wiring uses a rubber-with-cloth insulation over the copper wires. This kind of insulation is especially sensitive to heat. Older light fixtures had no insulation within them to protect the wiring from the heat of incandescent light bulbs. As a result, people would install larger 100-watt incandescent light bulbs in these fixtures, cooking the wiring in the junction box above.

BX wiring was installed with two-prong outlets, which will not accept three-prong cords. It is also ungrounded, meaning that new wiring cannot be extended off of BX wiring. For example, if you want to add a new outlet in a room and there is a nearby BX outlet, this outlet cannot be used to power the new outlet.

BX wiring is ungrounded and cannot be extended

BX wiring is an ungrounded wiring style. Although the exterior of the wire is metal, it was never intended to act as a ground. Instead, it was meant to protect the wire from damage. The metal exterior can act as a ground, but only if the connections at every box are tight. If one or more connections are loose, the ground becomes ineffective. This can be dangerous because, in the case of a short to ground, the circuit breaker will not trip, and the metal exterior of the wire will become live, carrying current back to the panel.

Since BX wiring is ungrounded, new wiring cannot be extended from it. For example, if you want to add a new outlet in a room and there is a nearby BX outlet, this outlet cannot be used to power the new outlet.

Three-prong outlets cannot be installed on BX wiring unless a GFCI outlet is used. However, even with a GFCI outlet, there is still no true ground present.

BX wiring is heavier and harder to handle than Romex wiring

BX wiring is heavier and more difficult to handle than Romex wiring. This is because BX wiring has a corrugated surface and a metal sheathing that makes it harder to pull through stud holes. The metal sheathing can also be challenging to cut without nicking or severing the inner wire.

In contrast, Romex wiring is lightweight and easy to handle. It has a slippery coating that allows it to be pulled through holes easily. Romex wiring is also cheaper than BX wiring.

While BX wiring is more difficult to work with, it offers some advantages over Romex. BX wiring is safer and provides better protection against accidental penetrations. It also has a metal sheathing that acts as a ground, although it was not originally intended for this purpose. Additionally, BX wiring is more resistant to being punctured by nails and screws, and it provides shielding against electric fields.

Overall, BX wiring is heavier and more challenging to handle than Romex wiring due to its metal sheathing and corrugated surface. However, it offers some benefits in terms of safety and protection that Romex does not provide.

Insurers may charge a higher premium for homes with BX wiring

BX wiring, also known as armoured cable, is the second generation of wiring used in homes. It was first introduced in the 1903 National Electrical Code book and was the main wiring type by 1932. It was used until the late 1940s when it was replaced by early Romex (non-metallic sheathed cable).

BX wiring is an ungrounded wiring style. Although the exterior of the wire is metal, it was never intended to be a ground. Instead, it was meant to protect the wire from damage. If the connections at the metal boxes are loose, the ground becomes ineffective. This can be dangerous if there is a short to ground, as the circuit breaker will not trip, and the metal exterior of the wire will be live, carrying current back to the panel.

BX wiring also has cloth insulation, which can break down to expose bare copper. This is particularly an issue in lights, where the heat from light bulbs has baked the wiring for years.

Given these issues, insurance companies may charge a higher premium for homes with BX wiring. Although BX wiring is safer than knob and tube wiring, it is still old wiring and can pose safety hazards. Therefore, insurance companies may view it as a higher risk and charge a higher premium.

In addition, BX wiring cannot be extended with new/modern wiring. Since BX wiring relies on the outer coverings to maintain a ground path, it is difficult to extend new wiring off of existing BX wiring.

Furthermore, BX wiring was installed with two-prong outlets, which cannot accept three-prong cords. This may require homeowners to upgrade their outlets, which can be costly.

Overall, while BX wiring is safer than knob and tube wiring, it still has some issues that may concern insurance companies. As a result, they may charge a higher premium for homes with this type of wiring.

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