How to Cut BX Cable: A Comprehensive Guide
Cutting BX cable requires precision and the right tools. Here’s how you do it correctly: Using a cable cutter or hacksaw with appropriate blade, carefully score and snap the armor, then cut the conductors with wire strippers.
Understanding BX Cable: A Background
BX cable, also known as armored cable (AC), provides a durable and protective covering for electrical conductors. Its interlocking metal sheath offers significant protection against physical damage, making it a popular choice for residential and commercial wiring applications. Understanding its construction is crucial before learning how do you cut BX cable?.
The Benefits of Using BX Cable
BX cable offers several key advantages:
- Physical Protection: The metal armor safeguards conductors from impacts and abrasions.
- Fire Resistance: The metal sheath can help contain electrical fires.
- Rodent Protection: Prevents rodents from damaging the wiring.
- Ease of Installation: Can be easily fished through walls and ceilings.
Tools and Materials Needed
Before we delve into how do you cut BX cable?, you’ll need the following tools and materials:
- BX Cable Cutter (Rotary Cutter) or Hacksaw with a fine-toothed blade.
- Wire Strippers.
- Screwdriver (for tightening connectors).
- Lineman’s Pliers (optional).
- Anti-Short Bushings (Redheads).
- BX Cable Connectors.
The Step-by-Step Process: How Do You Cut BX Cable?
Following these steps will guide you through the safe and effective cutting of BX cable:
- Measure and Mark: Determine the required length of the cable and mark it clearly.
- Score the Armor (Method 1: BX Cable Cutter): Place the cutter wheel on the marked spot and rotate the tool around the cable, applying gentle pressure. Continue until the armor is scored completely.
- Score the Armor (Method 2: Hacksaw): Carefully saw through the outer layer of the armor, using a fine-toothed blade and a sawing motion. Avoid cutting into the wires inside.
- Snap the Armor: Bend the cable back and forth at the scored point to snap the armor cleanly.
- Separate the Armor: Gently twist the cut end to separate the two sections of the armor.
- Cut Away Excess Armor: Using lineman’s pliers, carefully remove the excess armor, exposing the wires.
- Install Anti-Short Bushing (Redhead): Insert a redhead into the end of the armor to protect the wires from the sharp edges of the metal.
- Cut the Conductors: Using wire strippers, carefully strip the insulation from the ends of the conductors, preparing them for connection.
- Install BX Connector: Insert the cable end into a BX connector and tighten the screws to secure it.
Common Mistakes to Avoid
When learning how do you cut BX cable?, be aware of these common pitfalls:
- Cutting into the conductors: This is dangerous and can damage the wires. Use extreme caution when scoring or sawing the armor.
- Forgetting the Anti-Short Bushing: Leaving out the redhead can lead to shorts and potential fire hazards.
- Using the wrong tools: Using dull or inappropriate tools can damage the cable and increase the risk of injury.
- Stripping too much insulation: Exposing too much bare wire can create a safety hazard.
Comparison of Cutting Methods
| Method | Pros | Cons |
|---|---|---|
| BX Cable Cutter | Clean, precise cuts, faster than a hacksaw | Requires a specific tool, may not work on very thick BX |
| Hacksaw | More versatile, less expensive initial cost | Requires more skill and patience, can be less precise |
Safety Precautions
- Always disconnect power before working with any electrical wiring.
- Wear safety glasses to protect your eyes from metal shavings.
- Use insulated tools to prevent electrical shock.
- If you are not comfortable working with electricity, consult a qualified electrician.
Frequently Asked Questions (FAQs)
Can I use regular wire cutters to cut BX cable?
No, regular wire cutters are not designed for cutting BX cable armor. They are likely to damage the conductors and create a messy, unsafe cut. Always use a BX cable cutter or a hacksaw with a fine-toothed blade.
What is a “redhead” and why is it important?
A “redhead” or anti-short bushing is a small, plastic insert that protects the wires from the sharp edges of the cut BX cable armor. It prevents the metal from chafing the insulation and causing a short circuit. Always install a redhead after cutting BX cable.
What type of blade should I use on a hacksaw for BX cable?
Use a fine-toothed blade (typically 24-32 teeth per inch) designed for cutting metal. This will create a cleaner cut and reduce the risk of damaging the wires. Avoid using coarse blades that can tear the armor.
How do I know if I’ve cut too deep into the armor?
If you see exposed conductors or damage to the insulation, you’ve cut too deep. Discard the damaged section and start again. Practice on a scrap piece of BX cable to get a feel for the proper pressure.
What is the best way to avoid cutting into the conductors?
Apply light pressure when scoring or sawing the armor and stop as soon as you feel the blade breakthrough. Rotate the cable frequently to ensure a uniform cut.
Can I use a rotary tool (like a Dremel) to cut BX cable?
While technically possible, it’s generally not recommended. Rotary tools can be difficult to control and may create excessive heat and metal shavings. A BX cable cutter or hacksaw is a safer and more precise option.
What should I do if I accidentally damage the conductors while cutting BX cable?
If the damage is minor, you may be able to repair it with electrical tape or heat-shrink tubing. However, if the damage is significant, it’s best to replace the entire section of cable.
Do I need a special type of BX connector?
Yes, you need a connector specifically designed for BX cable. These connectors typically have a clamping mechanism that secures the cable and provides a grounding path. Ensure the connector is properly sized for the cable you are using.
Is it necessary to wear gloves when cutting BX cable?
While not strictly required, wearing gloves can provide extra grip and protection against sharp edges. Insulated gloves can also help prevent electrical shock, though always ensure the power is off before working with wiring.
What is the best way to dispose of the scrap pieces of BX cable armor?
Recycle the metal scrap at a local recycling center. Avoid throwing it in the regular trash as it can be a hazard to waste handlers.
How often should I replace my BX cable cutter blade?
Replace the blade when it becomes dull or damaged. A sharp blade will make cleaner cuts and reduce the risk of injury. The frequency of replacement depends on how often you use the tool.
Is cutting BX cable different in cold weather?
Cold weather can make the BX cable armor more brittle and prone to cracking. If working in cold conditions, take extra care when scoring and snapping the armor. It may be helpful to warm the cable slightly before cutting it.