The importance of making proper electrical terminations cannot be overemphasized.

“Terminations are the single most important part of an electrical installation,” said Joseph V. Sheehan P.E., curriculum specialist for the National Joint Apprenticeship and Training Committee (NJATC). “Without proper terminations, an electrical installation is a failure, period.”

Avoiding such failures requires correct installation of the right connectors with the right tools by trained, experienced electricians.

Sheehan said reliability is the key word and goal for electrical terminations.

“All electrical terminations on a job must be done in strict accordance with the National Electrical Code (NEC) and with the product listing and labeling instructions associated with the product in accordance with the manufacturer’s instructions,” he said. “A conductor and all the termination parts associated with its connection must be a matched set; the conductor, its connection, the parts of the terminal must be designed, manufactured and applied to prevent all types of termination failure and ensure reliability over its lifetime.”

In addition, trained electrical workers installing terminations must have the skills, knowledge and ability to perform the work according to the NEC and do the work in strict accordance with the manufacturer’s instructions.

“A trained electrical worker understands the difference between conductor materials, using and applying the proper crimp tool for the application, applying the proper insulation, and correctly applying the proper torque to the termination. A trained electrical worker becomes a major part of achieving the goal of correctly making each termination,” Sheehan said.

Below, representatives of four tool companies discuss terminations and the tools for making them.

Burndy (, Bob Poirier, senior product manager, said: “It is critical to follow the manufacturer’s recommendations when installing every type of connector for all applications.

“Dangers of improper terminations include damage to equipment, fire, potential injury to personnel or death. Connectors will run hot and eventually fail. A conductor will pull out of improperly made connections, causing the loss of the connection and potential power failure. Poorly made compression/crimp connections can be avoided by following the manufacturer’s recommendations for tools and dies and procedures to install them, including those for wire preparation and crimping.

“Required tools for mechanical connections are a cable stripper or knife to remove insulation, a wire brush to remove oxidation, and a torque wrench or a screw driver to tighten the connection.

“Compression/crimp connectors require a crimp tool. When installing compression connectors, tools can range from mechanical or ratchet tools for small-to-medium terminals and splices, to self-contained hydraulic or battery-actuated tools for medium-to-large compression connections. The biggest change in tools has been in battery technology with lithium-ion batteries.

“Small and medium compression lugs and splices can be installed with mechanical or ratchet crimp tools, but some medium-to-large terminations require a hydraulic or battery-actuated 6-, 12-, 15- or 60-ton tool to install and crimp it.

“Crimp tools can be dieless or may require a specific die for each connector or splice. There are applications that allow either tool type to be used. There also are applications that require using a crimp tool and die. When possible, standardize on one manufacturer for connectors and installation tools and follow their installation instructions.

“Hydraulic tools are faster and require less manual force to make a crimp. Battery-actuated tools continue to have faster crimp cycles, more crimps per battery charge, and they are lighter and more ergonomic. The increased speed, lowered installation costs and ease of use decrease the total cost, making these types of tools appealing,” Poirier said.

Greenlee (, Ryan Berg, senior product manager, said: “Manual tools are good for smaller connector sizes 8 to 4/0 AWG, occasional crimping of 250–400 kcmil, and always are good as a backup for other tools.

“Crimpers today are equipped with proprietary features that save time and reduce user fatigue. Tools with a pressure sensor feature notify the tool user with visual and audible alerts if the crimping force is below specifications for a successful crimp. Auto-retract opens the ram/jaws just enough to prep for the next crimping cycle, saving time and battery power. The RSR [retraction, stop, repeat] feature partially retracts the ram, sets tool memory and then repeats the retraction for subsequent crimps.

“Important-to-remember connection safety tips include using the right tool, use of the right crimping die if it is a die-type tool and the right number of crimps. Connector manufacturers have their tools listed with their own lugs and splices. Overcrimping can result in damaged strands and thin or broken connector walls. Copper lugs and splices may be used only with copper cable, while aluminum lugs and splices may be used with both aluminum and copper cable. Antioxidant material must be used with aluminum connectors,” Berg said.

Ideal Industries (, Bruce Hartranft, senior product manager, tools and supplies, said: “To cut wire, typically a handheld wire stripper or pliers that has a quality cutting edge can be used. For armored aluminum or steel cable, such as BX, MC, AC or Greenfield, a dedicated cable cutter is needed. The challenge here is to not nick the conductors, which could lead to a short circuit. Wire cutters, shears or hacksaws are not recommended for armored cable. Instead, use rotary cutters, a long-arm cutter, a ratcheting cutter, or one powered by a handheld drill.

“Heavier gauge wire or cables like MCM require a dedicated cutter to minimize cable distortion. NM, Romex, UF or other unique wires require a specially engineered stripper, so trying to use substitute tools will not create a reliable connection and can damage the wire. Armored cable is a fast growing segment of the cable market, but correct tools are required for its proper installation. NEMA RV 3-2600 guidelines recommend the use of rotary cutters for safely cutting flexible metal conduit and armored cable over methods that require breaking the armor and using cutting pliers.

“Handheld strippers need to match the wire gauge to correctly strip the insulating jacket. Most strippers have the AWG printed next to the stripping holes. Using the right tool according to its instructions, wire stripping should be a fast, easy job. The key is to avoid nicking the wire. A nicked wire can snap off when it’s bent to form a loop. If this happens, it’s best to snip it off and start again. It is very important to not nick stranded wires when stripping to create a connection. Cutting even a single strand can impact the ampacity of the wire and result in a dangerous high-resistance connection. Therefore, accuracy is very important. Wire strippers made in the United States are a good assurance that the stripper will accurately match American wire gauges.

“Quality crimping tools are needed for crimping on terminals, disconnects or splices. For performing repetitive crimps, a ratcheting crimp tool is recommended to minimize fatigue and ensure uniform crimps.

“Wire connectors are a key electrical system safety device. Wire connectors vary widely in quality, just as do tools. Features to look for include a live-action, square-wire spring that picks up quickly and holds the wire connection tightly without pretwisting and provides the leverage and torque needed on larger wire combinations. Some contractors prefer a wing design for a more secure grip, while others like the standard ribbed shell,” Hartranft said.

Panduit (, Bob Klaviter, business development manager, said: “Generally, hand tools can be employed to make smaller connector terminations for 8 to 1 AWG. Smaller battery-powered tools generating 6 tons of crimp force are available to terminate small to medium-size connectors from 8 AWG to 500 kcmil. Larger hydraulic-powered tools generating up to 15 tons of crimp force terminate connectors up to 1,000 kcmil.

“Improvements in lithium-ion battery technology provide significant increase in the number of crimps per battery charge, faster crimp cycle time, faster battery recharge cycle time and decreased weight of the tool.

“Some common problems resulting in poor terminations include:

• “Not using the proper crimp die for the connector being used: Crimp dies include color coding and die index number identification that should be matched to the corresponding color code and die index number marked on the connector.

• “Not using the proper connector for the wire type or wire size being terminated: Installers should be using connectors that are properly marked with the wire size and wire type the connectors are intended to terminate.

• “Improper stripping of the insulation from the wire: Wire should be stripped to the proper strip length, and nicking and bending back wire strands should be avoided when inserting into the connector as specified in the installation instructions included with product packaging.

• “Improper crimping technique used when terminating a connector to the wire: Installers must be formally trained in using proper installation techniques when terminating connectors and the correct use of installation tools and dies, and following the proper sequence when crimping connectors to wire,” Klaviter said.

In short, ensure you get the right connection tool to do the job.

GRIFFIN, a construction and tools writer from Oklahoma City, can be reached at