What is the best way to cut armoured cable?

Quick Answers

There are a few quick answers to keep in mind when cutting armoured cable:

– Use the proper cutting tools – specialized cable cutters or a hydraulic cutter are best for cleanly cutting through the metal armour. Regular diagonal cutters will likely struggle.

– Mark the cut location carefully with a permanent marker before cutting to ensure you are cutting at the right spot.

– Keep the cable stable and avoid kinking it during the cutting process.

– Wear safety glasses and gloves when cutting to protect yourself from sharp edges and flying debris.

– Make the cut at a 90 degree angle through all layers in one smooth motion for the cleanest cut.

– Avoid using an angle grinder or abrasive wheel as they may damage the inner conductors.

What Tools Do You Need to Cut Armoured Cable?

Cutting through the tough metal armour of armoured cable requires specialized tools that can cleanly shear through the jacket, armour, and inner conductors in one motion without crushing or deforming them. Here are some of the best tool options:

Armoured Cable Cutters

Dedicated armoured cable cutters are specially designed for this purpose and provide the best results. They have long, sharp blades that cleanly slice through all layers of the cable in one squeeze of the handles. Look for ratcheting cable cutters that help provide extra leverage for a smooth, easy cut.

Hydraulic Cable Shears

For large cables that standard cutters can’t handle, hydraulic cable shears are the ideal tool. Powerful hydraulic rams generate tons of cutting force to cleanly shear through cable armour up to 4 inches in diameter. They offer fast, easy, one-step cutting.

Hacksaw

For occasional cuts, a hacksaw with a fine-toothed metal cutting blade can work. Secure the cable to prevent kinking and carefully saw back and forth through the jacket, armour and inner conductors. It takes more effort but makes a clean cut.

Bandsaw

A portable bandsaw with a metal cutting blade is also effective at cleanly slicing through armoured cable. Clamp the cable securely and guide the blade slowly through the cable at a 90 degree angle. Use caution as the blade may catch and jump.

Abrasive Chop Saw

While not recommended for the inner conductors, an abrasive chop saw with a metal cutting wheel can slice through the outer armour jacket if done carefully. Keep the cable stable and cut only from one side to prevent damage.

Step-by-Step Cutting Armoured Cable Instructions

Follow these key steps to properly cut through armoured cable for a safe, clean cut:

1. Select Your Cutting Location

Carefully measure and mark the exact location you want to cut the cable with a permanent marker. Try to make the cut in an accessible area with enough room to operate the cutting tools. Cutting too close to a connection point can damage the termination.

2. Secure and Straighten the Cable

Clamp the cable or have someone hold it to prevent kinking or bending during cutting. Straighten out any bends at the cut location to allow for an even cut through all layers. Pull it taut if able.

3. Put On Safety Gear

Wear safety glasses and gloves when cutting to protect your face and hands from sharp edges, burrs and flying pieces of the metal jacket. Proper eye protection is critical during cutting.

4. Position Your Cutting Tool

Place your cutters, shear or saw at the marked cutting location, making sure it is at a 90 degree angle across the full diameter of the cable. Keep hands safely clear of the blade.

5. Cut Slowly Through All Layers

Start cutting slowly and steadily, allowing the tool to slice through the jacket, metal armour and inner conductors in one smooth motion. Don’t twist or bend the tool during cutting. Apply even pressure.

6. Inspect the Cut

Check that all layers have been completely cut through with no intact strands left. The inner conductors should be cleanly severed with no crushing, kinking or other damage.

7. File Any Burrs or Sharp Edges

Use a metal file to smooth out any rough or sharp edges left on the cut armour. Remove all burrs to prevent the sharp edges from damaging the inner conductors.

Following these proper cable cutting techniques will help produce a professional, safe cut ready for terminating or splicing. Avoid shortcuts that could kink or damage the cable. And be sure to use the right cutting tool for the cable size and type.

Cutting Errors to Avoid

Cutting armoured cable incorrectly can lead to hack-job results and even serious electrical hazards. Here are some key errors to avoid:

• Using the wrong cutting tool – Diagonal cutters cannot cleanly cut through armour.
• Failing to secure the cable – Allowing it to bend or kink during cutting damages conductors.
• Cutting at an angle – Must cut perfectly perpendicular through all layers.
• Twisting the cutting tool – Applying torque stresses and distorts the cable.
• Cutting part way into the cable – Must cut completely through in one motion.
• Damaging inner wires – Avoid crushing, kinking, or stripping insulation.
• Leaving sharp edges – Burrs left on armour can penetrate insulation over time.

Rushing through the cut or using the wrong technique can ruin the cable end, requiring starting over. Follow the proper step-by-step cutting procedures above to avoid these mistakes.

How to Cut Different Types of Armoured Cable

While all armoured cables have a metal protective jacket, there are differences in how the inner conductors are constructed for various cable types. Here are tips on cutting the most common varieties:

AC Cable (BX)

– Has woven metal armour surrounding rubber-insulated inner wires
– Cut completely through armour and inner wires simultaneously
– Best cut with specialized diagonal cutting pliers

MC Cable

– Features a plastic jacket under spirally-wound metal armour
– Cut through plastic outer jacket first, then cut armour and wires
– Use dedicated cable cutters for clean cut

TEC Cable

– Contains small gauge wires embedded in a fabric tape under armour
– Cut all layers in one shearing motion
– Ratcheting cable cutters work well

AC Weld Cable

– Has hundreds of flexible fine strands under the armour rather than solid conductors
– Avoid crushing or kinking the fine strands when cutting
– Use hydraulic shears for clean cut

High Voltage Cable

– Cut same as other armoured cable but exercise extreme caution
– Ensure armor is grounded when cutting due to stored charge

Always inspect and test cables after cutting to ensure insulation integrity before using. The goal is to cut through all layers without compromising the inner conductors.

How to Strip Cut Armoured Cable Properly

After cutting armoured cable, the next step is “stripping” – removing a section of the outer armour to expose the inner conductors for connecting terminations. Here is how to strip properly:

1. Carefully Mark Strip Length

Measure and mark where the jacket/armour needs to be removed using a permanent marker. Common strip lengths are 1/2″ for small branch circuit wiring or 2″ for large feeder cables.

2. Score Around Armour

Use a sharp knife to slice through and score the outer jacket and armour completely around the circumference at your marks. Be careful not to damage inner insulation.

3. Slit Lengthwise

Make a small slit or opening with your knife along the length of the marked section. Insert cutting pliers into slit.

4. Twist Off Armour

Grab pliers onto exposed armour through slit and twist counter-clockwise to begin unwinding armour from cut opening. Continue unwinding armour strip off cable.

5. Smooth Edges

Use a file to smooth any sharp edges or burrs left on the remaining armour after stripping to prevent cutting inner insulation.

6. Cut Away Excess Inner Insulation

If needed, carefully trim back any inner wire insulation to achieve desired strip length of bare conductor for terminations.

Avoid nicking or damaging inner conductors when stripping. Use the right tools and techniques for the cable type to achieve clean, undamaged results. Proper stripping helps ensure solid electrical connections.

Cable Cutting Safety Precautions

Working safely is critical when cutting and stripping armoured cable due to hazards such as sharp edges and potential arc flashes. Here are important safety steps to follow:

– Wear eye protection and gloves at all times.

– Make sure cable is de-energized and locked out before cutting.

– Secure cable to prevent kinking and bending during cutting.

– Double check cut location before cutting to avoid mistakes.

– Keep fingers safely away from cutting blades. Watch out for sharp edges.

– File or trim any rough armour edges after cutting to remove sharp burrs.

– Don’t use cutting tools near flammable materials or gases.

– Periodically service and sharpen cutting tools to keep them in top condition.

– Dispose of cable scraps properly to avoid tripping or fall hazards.

– Inspect completed cuts and test cable integrity before returning to service.

– Exercise extreme caution when cutting high voltage cables due to arc flash hazards.

Following good safety practices will help protect yourself and the cable from harm. Rushing through cutting risks mistakes, injury and damaged cables.

Tips for Cutting Armoured Cable in the Field

Sometimes armoured cable must be cut and stripped during installations, repairs or modifications in live facility environments rather than the controlled conditions of a shop. Here are tips for cleanly cutting and stripping cable in the field:

– Have adequate working space. Make sure the area has enough room and clearance to safely operate your cutting tools. Avoid cluttered spaces.

– Bring all necessary tools and supplies. Carry the specific cable cutters, wrenches, knives, and files you’ll need so you don’t have to improvise. Have spare cutting blades.

– Secure cable position. Set up clamps, vises or have helpers hold the cable stable so it doesn’t bend or kink during cutting.

– Protect surfaces below. Put down drop cloths or cardboard to catch scraps and prevent paint and floor damage.

– Control cable ends. Be cautious of loose cable ends after cutting so they don’t whip around and cause injury.

– Clean up debris. Pick up any loose pieces of armour, etc to prevent slip, trip and fall hazards. Dispose of scraps properly.

– Touch up cut cable. File any burrs, re-straighten kinked conductors, apply corrosion protection to exposed armour.

– Inspect your work. Double check for proper cut and strip before moving on with the job.

With some advance planning and organization, you can achieve professional, safe results cutting armoured cable in less than ideal field conditions.

How to Cut MC Cable (Metal Clad)

MC cable is a common electrical wiring method, providing conductors in a flexible metal armor jacket. Use the following steps when cutting metal clad cables like MC & AC cables:

1. Mark Cut Location

Measure and mark the jacket using a permanent marker where you want to cut through the MC cable. Double check your measurements.

2. Straighten the Cable

Hold or clamp the MC cable to prevent kinking and straighten out the section to be cut so the cut is squarely across the cable.

3. Score Cable Jacket

Use a sharp utility knife to make a shallow cut completely around the MC cable jacket at the marked location. This allows access for other cutters.

4. Attach Cutting Pliers

Lock the correct size diagonal cutting pliers onto the scored opening in the MC cable. Ensure they are at a 90 degree angle.

5. Shear Cleanly Through All Layers

Squeeze pliers firmly in one smooth motion to cut through the jacket, metal armor, paper fill and internal wires all at once.

6. File Any Burrs

Use a metal file to remove any rough burrs or sharp edges left on the armor after cutting to smooth the end.

7. Pull Back Paper Fill

Strip a short section of paper fill away from the cut end to allow access to the inner conductors for connections.

Double check the cut and strip for any damage before using the MC cable. Avoid hacksaw or abrasive wheel cuts that may damage conductors.

Cutting EMT Conduit

Cutting electrical metallic tubing (EMT) conduit is similar to cutting armoured cable in terms of technique but on a smaller scale. Follow these guidelines when cutting EMT:

• Use an EMT conduit cutter for best results. Tubing cutters make straight, non-deforming cuts.
• A hacksaw also works though results may be less neat looking. Use a fine metal blade.
• Mark the cut location with a permanent marker allowing room for connections.
• Secure conduit with a vise or clamps to prevent bending while cutting.
• Line up cutter wheel perpendicular to the length of conduit and spin to score around tube.
• Flex the conduit back and forth to snap off at score mark. File any burrs.
• For thicker conduit, cut completely through both sides with cutter wheel to avoid deforming.
• Wear safety glasses when scoring and breaking conduit to protect eyes.

Cutting EMT is easier than armoured cable thanks to the thinner metal and smaller diameters. But take care to make straight cuts and remove burrs to prevent damage to wiring pulled through later.

Planning Your Cuts

Proper planning of where and how you’ll cut the armoured cable ensures you get it right the first time. Keep these guidelines in mind:

– Carefully measure twice before marking cut locations.

– Leave ample length for connections and terminations after cutting.

– Verify there is adequate clearance for cutting tools before starting.

– Have the cable positioned and secured to prevent kinking or bending.

– Confirm you have the right cutting tool for the cable size and type.

– Check for hazards like flammable gases or vapors before cutting.

– Make sure cable is de-energized and locked out before cutting.

– Communicate with coworkers about where and when you are cutting cable.

– Allow extra length for stripped conductors to ease working connections.

– Validate cut location with supervisor or electrician before cutting expensive cable.

Proper planning makes cutting armoured cable quicker, easier and safer. Rushing in without preparation risks wasted time, damaged cables and injuries. Think through all aspects of the task up front.

Armoured Cable Cutting Checklist

Cutting armoured cable properly involves several steps. Here is a helpful checklist:

– Identify cable to be cut and determine cutting location

– Select the proper cutting tool for cable size and type

– Inspect tool for sharp, undamaged blade or wheel

– Verify cable is de-energized and locked out

– Put on required PPE – glasses, gloves, etc

– Clean work area and remove nearby hazards

– Carefully mark cut location on cable jacket

– Secure cable in vise or clamps if possible

– Straighten cable at cut location so it is not kinked

– Position cutting tool squarely on marked cut location

– Cut completely through all layers in one smooth motion

– Inspect cut to ensure conductors are undamaged

– File and smooth any rough or sharp edges on armour

– Clean up all metal scraps and debris from cutting

Following this checklist helps ensure you make cuts safely and professionally the first time. Cable cutting requires care and preparation for best results.

Conclusion

Cutting through armoured cable’s tough metal jacket requires using the proper cutting tools and techniques to avoid damaging the vital inner conductors. Specialized hydraulic or ratcheting cable cutters, along with saws or abrasive blades, allow slicing cleanly through all layers when done carefully. Always wear protective gear and make cuts at precise marked locations on secured cable to achieve safe, professional results. With planning and practice, electricians can master the unique considerations of successfully cutting armoured cables on the job.