Published: September 2007
Making an electrical connection is such a routine task that it can be easy to overlook how critical it is to make every connection carefully and correctly. Electrical systems not only depend on properly made connections to function, but faulty connections can be a life-or-death matter.
“Shorts or power quality problems are other very frequent consequences of improper electrical connections,” said Bruce Hartranft, business unit manager, Ideal Industries. ”For the electrical contractor, this translates into time-consuming ‘call-backs’ that drain the profitability out of an otherwise profitable job. The unfortunate and continued use of outdated knives for stripping and cutting wires results in nicked insulation and shorts. The fallout of cutting corners by using old, cheap tools is more work, the need to make repairs earlier, or the consequences can be much more serious.”
The worst-case scenario—fire and death—is tragically common, Hartranft said.
“According to the U.S. Fire Administration,” he said, “during a typical year, home electrical problems account for 67,800 fires, 485 deaths and $868 million in property losses. In urban areas, faulty wiring accounts for 33 percent of residential electrical fires.”
Correctly made electrical connections can help reduce these figures.
Connectors fall into two general categories, mechanical and compression, and the tools required depend on the type of connector, how it is to be used, and size and type of cable.
The basic tools required include cable cutters, strippers to remove the insulating jacket, hand tools for making mechanical connections, and crimping tools to install compression connectors by either compressing or “crimping” a connector around a prestripped wire or cable, or by pushing wire or cable into a connector designed to pierce or displace the insulation and attach to the conductor.
While the types of connection tools have not changed, the latest tool models help electricians make good connections faster and more efficiently than those sold a few years ago.
Representatives from four manufacturers discussed the importance of properly made electrical connections, consequences of improperly made ones and how connection tools have evolved.
FCI-Burndy Products, Bob Poirier, senior product manager: “The importance of making a proper connection is really clear when considering what happens if it is not made properly—there is the possibility of overheating, which can lead to equipment failure, loss of power and the possibility of injury or death.
“Compression connections use crimpers with compression terminals and splices. The most popular type of crimpers are available in mechanical, hydraulic and battery-actuated tool platforms. Mechanical and bolted connections are made with a screwdriver and Allen wrench. In addition, exothermic connections for grounding use special molds and weld metal. For the smaller cable sizes, contractors would traditionally install connectors with mechanical or ratchet-type tools. For medium to large cable/connector sizes, the industry is heading toward hydraulic and battery-actuated for speed and ergonomics.
“Poorly made connections often result from using the wrong connector size for cable being connected, the wrong connector for the application, not properly cleaning or preparing the conductor and using the wrong tool-die combination.
“Today, battery-actuated tools are becoming more popular because they make connection installation much faster. There is a move to take popular tool heads and redesigning them for battery platforms. The die embossment feature verifies immediately that the proper tool and die were used for the connection. Dieless tools eliminate the possibilities of using the wrong tool/die combination. There is a larger market for battery-actuated cutters.
“As engineering technology improves, tools are becoming lighter with added focus on ergonomics. Crimp speed and the number of crimps per charge have increased. Demand for better tools and performance brings constant updates of tool products.”
Greenlee Textron, Jim Eisele, senior product manager: “Hydraulic tools are faster and lighter than even five years ago. Battery tools are lighter and faster than hydraulic tools. In some cases, battery tools are actually lighter than manual tools with the same capacity. These tools are also much smaller than manual tools, so they are significantly easier to use in tight locations. Within the past two years, Greenlee has introduced a 12-ton multi-function crimping tool and dieless crimping tool.
“As cable size gets larger, the force required to crimp a connector becomes larger. Thus, the tools must provide more force. Manual tools are easy to use up to about 4/0 AWG, and they can be used up to about 400 kcmil. Above these sizes, hydraulic or battery tools need to be used to achieve the needed forces.
Ideal Industries, Bruce Hartranft, business unit manager: “The importance of a safe electrical connection can’t be overstated. When a contractor from another trade does something wrong—say a carpenter—the kitchen cabinets are not level or the floor may sag. When an electrician makes a mistake in a wire connection, the house can burn down. Connecting properly also makes a measurable difference in a building’s power quality, energy efficiency and the overall quality of the wiring system.
“The source of virtually every bad wiring connection is the combination of improperly stripped wires and shoddily terminated connections. Sometimes, bad connections result from an electrician lacking basic training; other times the contractor is simply in too much of a hurry to do the job right. More times than not, however, it is because of the use of second-rate equipment.
“With so much at stake, from the lives of the building’s occupants to the contractor’s professional reputation, it doesn’t make sense to use anything but the best equipment and supplies money can buy to make connections.
“Compared to yesterday’s tools, current strippers and wire connectors are faster, safer, more efficient and easier to use. The efficiency issue is especially important as increasing labor costs, combined with a skilled labor shortage, means electrical contractors have to get more work done in less time with fewer trained electricians. Newer tools from Ideal include screwdrivers with connector nut built in, wire strippers with ergonomically shaped grips with thumb valley, and power cutting attachments that attach to a power drill.”
Panduit Corp., Tim Oliver, business development manager: “Improper electrical connections are one of the major contributors to electrical problems in the field. On control power connections, it could result in machine downtime. However, with high-power connections, it could result in hot spots, fires and possibly personal injury. That is why knowledge of performing and inspecting a proper crimp is paramount; correcting an improper termination at the time of the crimp can literally cost pennies and ensure quality and reliable performance. Letting it go can result in product failure, intermittent connections, safety issues, etc., resulting in a problem that can cost a company thousands of dollars [in] potential repairs, customer down time, costly field service and damage to reputation.
“Not only are today’s tools faster and easier to use, most importantly, they are more consistent. For example, as the name implies, a controlled-cycle tool controls the cycle of the crimp. The internal ratchet mechanism will not release until the tool has been completely squeezed shut. A controlled-cycle tool will perform the electrical and the insulation crimp in one cycle of the tool (it takes a separate crimp with a pliers-type tool). And a controlled cycle tool will do all of this with 50 percent less handle effort than is required to crimp with pliers-type tools. The controlled cycle tool doesn’t get sick, weak or take vacation. It makes the same crimp regardless of who squeezes the handles closed.
“Improper electrical connections can result in many problems. Some of the causes can be traced to not matching the correct tool to the terminal or connector, not using tools and terminals from the same manufacturer (most are unaware that UL does not recognize a termination unless the terminal manufacturer’s crimp tools are used), failure to match terminal to wire size, not properly preparing wire and failing to select the proper terminal to the application. Improper use of tools also can cause problems, as does using any tool available just to get a job done.
“How to avoid poorly made connections? Training, training, training! There is no substitute for proper training. Training should include theory regarding wire sizing and wire construction. It should include information on terminals and connectors [and] their materials, uses and configurations. Finally, it should include hands-on crimping that demonstrates not only the proper way to crimp, but what bad crimps look like and what potential hazards they can bring. Many installers have no idea what the consequences are (in safety and dollars) of a poor crimp. Refresher training should be mandatory so that everybody is on the same page and performing the same way.” EC