Portable power tool

Cameras, rechargeable appliances such as portable power tools, hand-held vacuums, etc. 

Nickel-cadmium, or "ni-cad," batteries are popular for use in calculators and portable power tools because, unlike most other dry-cell batteries, they are rechargeable (Figure 18.11). The anode of a ni-cad battery is cadmium metal, and the cathode is the nickel(III) compound NiO(OH) supported on nickel metal. The electrode reactions are... 

Subpart P—Hand and Portable Powered Tools and Other Handheld Equipment (1910.241 — 1910.247) 1910 Subpart Q— Welding, Cutting, and Brazing (1910.251 — 1910.257)... 

A quarter of all serious electrical accidents involve portable electrical appliances that is, equipment which has a cable lead and plug and which is normally moved around or can easily be moved from place to place. This includes, for example, floor cleaners, kettles, heaters, portable power tools, fans, televisions, desk lamps, photocopiers, fax machines and desktop computers. There is a requirement under the Health and Safety at Work Act for employers to take adequate steps to protect users of portable appliances from the hazards of electric shock and fire. The responsibility for safety applies equally to small as well as large companies. The Electricity at Work Regulations 1989 also place a duty of care upon employers to ensure that the risks associated with the use of electrical equipment are controlled. 

Subpart P — Hand and Portable Powered Tools and Other Hand-Held Equipment... 

General industry rules on hand and portable powered tools not specifically covered in the construction regulations. 

General industry regulatory text 29 CFR 1910, Subpart P — Hand and portable powered tools and other hand-held equipment. 

Isolation and Double Insulation Another form of physical control is separating energized portions of electrical equipment from those parts people can contact This is isolation. Several means can accomplish isolation. Covering conductors with nonconductive materials keeps people from contacting them. This is insulation. Another method is to provide two layers of enclosure for energized parts. At least one of the layers must be nonconductive and the nonconductive layer must separate a user from possible contact with any energized part. This is double insulation. Most portable power tools (drills, saws, etc.) have internal parts that cannot energize any portion of the external surface. 

Users of portable power tools need training to use them safely and properly. Training should include how to operate the tools. Users need to understand the hazards of each tool, its action, and power supply. They need to know about built-in protections. They need to know how to protect themselves from hazards during use. They need to know how to maintain and store the tools. 

Like other tools, portable power tools have designs for particular tasks. If used for other tasks, they may create additional hazards. 

What safeguards are important for portable power tools ... 

Hand Tools Portable Power Tools Proper tools available Tools in good condition Power tools grounded or insulated Gas powered equipment vented ... 

Does the facility use portable power tools that have an exposed point of operation that creates a hazard to the employee ... 

Grinding wheels rotate at high speeds and have the potential to break apart (explode). Thus, abrasive wheel machinery and portable power tools should only be used on machines provided with safety guards, with the following exceptions ... 

Abrasive wheel machinery and portable power tool safety gnards must cover the spindle end, nut, and flange projections, except... 

The employer is responsible for the safe condition of all tools and equipment used by employees but the employees have the responsibility for properly using and maintaining such tools. Employers should caution employees that saw blades, knives, or other tools be directed away from aisle areas and other employees working in close proximity. Knives and scissors must be sharp. Dull tools can be more hazardous than sharp ones. Appropriate personal protective equipment (e.g., safety goggles, gloves, etc.) should be worn due to hazards that may be encountered while using portable power tools and hand tools. 

Provide and maintain plant and systems of work that are safe and without risks to health. Plant covers any machinery, equipment or appliances including portable power tools and hand tools. 

To remove the need for earthing on some portable power tools, double insulation is used. Double insulation employs two independent layers of insulation over the live conductors, each layer alone being adequate to insulate the electrical equipment safely. Since such tools are not protected by an earth, they must be inspected and maintained regularly and must be discarded if damaged. 

Figure 14.8 shows the symbol which is marked on double insulated portable power tools. 

The nickel—cadmium cell (nicad cell) is a conunou storage battery. It is a voltaic cell consisting of an anode of cadmium and a cathode of hydrated nickel oxide (approximately NiOOH) on nickel the electrolyte is potassium hydroxide. Nicad batteries are used in calculators, portable power tools, shavers, and toothbrushes. The half-cell reactions during discharge are... 

Category Guarding of Portable Powered Tools (1910.243) Abrasive wheels... 

Since portable power tools are frequently used on ladders, scaffold structures and platforms, a relatively common result of a person experiencing an electric shock when using a power tool under these working conditions is a fall from height leading to impact injuries. 

There are several basic safety practices that can help prevent accidents and unsafe use of hand and portable power tools. These include (Kimball, 2000) ... 

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