Maintaining Portable Electric Power Tools

It is important that the right portable electric power tools be available when needed. However, this is of no value if the tools are not in good working order and able to effectively and safely perform the work. Portable electric power tools not maintained and in good working order are first and foremost a safety hazard. Secondly, poorly maintained portable electric power tools will affect both the productivity and morale of those using them. The cost of providing adequate and well-maintained portable electric power tools to field personnel is small compared to the cost of lost productivity or a resulting accident. Where does good tool maintenance start? Good tool maintenance starts with the proper use of tools at the work site. Field personnel must know how to select the right tool for the job and then understand how to use it properly. Training in proper selection and use of these tools is key to trouble-free use and long tool life. Manufacturers design portable electric power tools for specific applications and, like any piece of equipment, they have their limitations. Using the wrong tool for a job can result in damage to the tool and/or injury to the user. Attempting to use a tool beyond its rating or for a job it was not designed for is begging for trouble. Misapplying and overloading a portable electric power tool may result in damage to its electric drive motor and its mechanical mechanisms. Selecting the right tool for the job is only the first step. Using these portable electric power tools properly is equally as important. Tools must be used in accordance with manufacturer recommendations and instructions. This includes the use of personal safety equipment such as safety glasses, hearing protection, and other protective clothing and accessories. Users should read and follow any operating instructions provided with the portable electric power tool and heed any warnings or directions stamped on the tool. Misusing a power tool can damage the tool and can be very dangerous. Only accessories and attachments specifically manufactured for use with the tool should be used. Don’t skimp on expendables Portable electric power tools are only as good as the bits, blades, or dies that actually do the work. These items are expensive to purchase but not nearly as expensive as the lost productivity caused by worn bits, blades, and dies or the wear and tear they cause to portable electric power tools. Doing the same job with worn bits, blades, and dies often takes longer, requires the tools to work harder, and results in a lower-quality installation. In addition to being harder on the tool, worn bits, blades, and dies also require more effort from field personnel to get the job done, which impacts productivity and morale. To avoid unnecessary wear and tear on portable power tools and installer fatigue, don’t skimp on accessories. First, make sure the field has the right sizes and types of bits, blades, and dies to do the work. Not having the proper items will require field personnel to do the best they can with what they have to get the job done. Again, this can result in damage to tools, and lost productivity, low morale, and possible injury. In addition to having the correct expendables, sufficient quantities of these items must be available so they can be changed out when needed. There is no doubt that these items are expensive and should be sharpened or otherwise recycled whenever possible. However, it is false economy to believe the wear and tear on power tools and lost productivity arising from cheap or worn bits, blades, or dies, is cheaper than replacing them when needed. Battery packs for portable electric power tools should also be considered expendable. Batteries also grow weak and wear out over time and need to be replaced. Sufficient battery packs and chargers should be kept onsite to ensure field personnel will never be waiting for a battery to charge. Also, if the work requires installers to repeatedly change bits, blades, or dies, consider providing multiple portable electric power tools to avoid repeated change outs, which contributes to tool wear and tear and installer fatigue. Inspect before using It should be standard operating procedure for field personnel to perform visual inspection of portable electric power tools before using them. Taking a moment to visually inspect the tool can reveal problems that could result in a safety hazard or serious damage if not corrected before use. Some of the things that should be looked for on visual inspection include: • Cracked or otherwise damaged casings and enclosures • Broken or damaged chucks or attachment mechanisms for bits, blades, or dies • Missing, damaged, tampered-with, or improperly operating safety guards, shields, or other safety features • Properly operating on-off switches • Excessive dirt, grease, or other buildup on any part of the portable electric power tool, including ventilation openings • Cut, frayed, spliced, or otherwise damaged power cords • Cracked or damaged attachment plugs, including missing or deformed grounding pins If these or any other problems are noted during the visual inspection, the tool should be tagged “Do Not Use.” The tool should then be returned to the shop for repair or replacement. Tags should not be removed until repaired and tested. If a portable electric power tool is going to be disposed of, it should have its power cord completely removed and be disposed of with the warning tag attached so that anyone finding the tool later will know that it is damaged and should not be salvaged or used. Problems during use If a problem is discovered when operating a portable electric power tool, cease work with that tool immediately and fix the problem or replace the tool before proceeding. For example, if a person using a portable power tool experiences a shock or even a tingle, that tool should immediately be tagged “Do Not Use” until it has been fully tested and has had any problem corrected. Removing a tool from service can prevent further damage and safety hazards. After-use inspection, cleaning, and testing When portable electric power tools are returned to the shop after being used on a project, they should be thoroughly inspected, cleaned, and tested prior to being sent back out to the field. If calibration is required, the tool should be calibrated in accordance with manufacturer recommendations and a calibration stamp should be placed on the tool that notes not only that the calibration was done, but also when the next calibration should be performed if that is appropriate. Tools carried on service trucks in continuous use should also be scheduled for periodic inspection, cleaning, and testing. Extension cords Portable power tools and equipment on construction sites are needed where the work is being performed, which may be some distance from the nearest outlet. Therefore, extension cords must be used when battery-powered tools are not available or practical. Extension cords should be inspected prior to use to ensure that they are in good condition. To avoid excessive voltage drop on extension cords that can have adverse effects on tool performance and result in damage to the tool, extension cord lengths should be kept to a minimum and an adequate conductor size used. National Fire Protection Association’s (NFPA) publication NFPA 70B entitled Recommended Practice for Electrical Equipment Maintenance, provides recommended sizes of extension cords in American Wire Gage (AWG) along with maximum length in feet for portable electric tools in Table 17-5. This table is based on a current equivalent to 150 percent of tool full-load and a maximum 5-volt voltage drop. The NFPA’s recommended conductor size and length for extension cords powering portable electric tools and equipment is reproduced in the table above. Tool tracking system Either a manual or computerized tool-tracking system should be used to track the location and status of all portable electric power tools. This tracking system should include information describing the tool, when the tool was acquired; where it is currently being used; and its maintenance, repair, and calibration history. This tool-tracking system should be part of the electrical contracting firm’s quality assurance program, and procedures should be documented and put in place that address the maintenance, calibration, and testing of portable electric power tools. Acknowledgement This article is the result of ongoing research into the development of service contracting business by electrical contracting firms sponsored by the Electrical Contracting Foundation, Inc. The author would like to thank the foundation for its continuing support. GLAVINICH is Chair and Associate Professor of Architectural Engineering at The University of Kansas. He can be reached at (785) 864-3435 or

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