Power Tools - Engineering

 1BLOG POST LAYOUT FOR MAINS POWERED TOOLS 

SAFE USE OF  MAINS POWERED TOOLS AND EXTENSION CORDS 

Describe/ Explain what is a mains powered power tool

• A power tool is a tool that is actuated by an additional power source and mechanism other than the solely manual labor used with hand tools. The most common types of power tools use electric motors. Internal combustion engines and compressed air are also commonly used. Other power sources include steam engines, direct burning of fuels and propellants, such as in powder-actuated tools, or even natural power sources such as wind or moving water. Tools directly driven by animal power are not generally considered power tools.

Where are you likely to use it?

• Power tools are used in industry, in construction, in the garden, for housework tasks such as cooking, cleaning, and around the house for purposes of driving (fasteners), drilling, cutting, shaping, sanding, grinding, routing, polishing, painting, heating and more.

Give 3 examples of a mains power tool you may have already used. 

Scroll Saw

Describe/explain the task you used it for.

Scroll Saw - I used the scroll saw when we were making a wooden sundial.

General safety around electricity. 

What to look for….

• Inspect portable cord-and-plug connected equipment, extension cords, power bars, and electrical fittings for damage or wear before each use. Repair or replace damaged equipment immediately.

• Always tape extension cords to walls or floors when necessary. Do not use nails and staples because they can damage extension cords and cause fire and shocks.

• Use extension cords or equipment that is rated for the level of amperage or wattage that you are using.

• Always use the correct size fuse. Replacing a fuse with one of a larger size can cause excessive currents in the wiring and possibly start a fire.

• Be aware that unusually warm or hot outlets or cords may be a sign that unsafe wiring conditions exists. Unplug any cords or extension cords from these outlets and do not use until a qualified electrician has checked the wiring.

• Always use ladders made with non-conductive side rails (e.g., fibreglass) when working with or near electricity or power lines.

• Place halogen lights away from combustible materials such as cloths or curtains. Halogen lamps can become very hot and may be a fire hazard.

• Risk of electric shock is greater in areas that are wet or damp. Install Ground Fault Circuit Interrupters (GFCIs) as they will interrupt the electrical circuit before a current sufficient to cause death or serious injury occurs.

• Use a portable in-line Ground Fault Circuit Interrupter (GFCI) if you are not certain that the receptacle you are plugging your extension cord into is GFCI protected.

• Make sure that exposed receptacle boxes are made of non-conductive materials.

• Know where the panel and circuit breakers are located in case of an emergency.

• Label all circuit breakers and fuse boxes clearly. Each switch should be positively identified as to which outlet or appliance it is for.

• Do not use outlets or cords that have exposed wiring.

• Do not use portable cord-and-plug connected power tools if the guards are removed.

• Do not block access to panels and circuit breakers or fuse boxes.

• Do not touch a person or electrical apparatus in the event of an electrical incident. Always disconnect the power source first.

( https://www.ccohs.ca/oshanswers/safety_haz/electrical.html)

What do I do if something is wrong . ( Fault Reporting )

 

What to do in an electrical emergency

If your whole area loses power:

• The local lines company will be working on the problem as soon as it occurs. If you work in a remote or rural area, call your local faults number to log the fault.

• Turn off appliances and electrical equipment – some can be a fire hazard and others might be damaged when the power comes back on.

 If your place is the only one without power:

• Check your fuse box to see if it's still working.

• If your fuse box seems to be working, you may have a fault in the supply to your premises.

 What to do in an electrical accident:

• Don't touch the injured person if they're still in contact with a live electrical source.

• Switch the source of electricity off, or if you can't, move the source away from you and the injured person using a non-conducting object like a wooden broom handle. Then dial 111 for an ambulance immediately.

(https://contact.co.nz/support/emergencies-faults-and-outages#What-to-do-in-an-electrical-emergency)

 General hazards and dangers of a mains powered power  tool

Use google to find out what these are and what they do attached a photo of each one 

Residual current devices		A Residual Current Device is a sensitive safety device that switches off electricity within 10 to 50 milliseconds if there is a fault. An RCD is is designed to protect against the risks of electrocution and fire caused by earth faults.
Isolating transformers		An isolation transformer is a transformer used to transfer electrical power from a source of alternating current power to some equipment or device while isolating the powered device from the power source, usually for safety reasons.
Monitored-earth circuits		A GCM or ground continuity monitor (also called a ground integrity monitor or ground continuity tester) is an electrical safety device that monitors the impedance to ground of a temporary electrical circuit and can provide indication (or protective trip) in the event impedance rises to an unsafe value.
Double insulated tools		Hand-held tools manufactured with non-metallic cases are called double-insulated. If approved, they do not require grounding under the National Electrical Code. Although this design method reduces the risk of grounding deficiencies, a shock hazard can still exist.
Other electrical isolators

  

Answer these questions

Explain how an “RCD” works  Why is it important

• RCDs operate by measuring the current balance between two conductors using a differential current transformer. This measures the difference between current flowing through the live conductor and that returning through the neutral conductor.

• Why is it important?: An RCD is designed to protect against the risks of electrocution and fire caused by earth faults. For example, if you cut through the cable when mowing the lawn and accidentally touched the exposed live wires or a faulty appliance overheats causing electric current to flow to earth.

Explain what is meant by “Double Insulation” Why is it important

• Double insulation is insulation that consists of both basic insulation and supplementary insulation. Equipment such as hand-held domestic electric drilling machines has the additional safety precaution of double insulation.

• Why is it important?:This is because they have plastic casings, or they have been designed so that the live wire cannot touch the casing. As a result, the casing cannot give an electric shock, even if the wires inside become loose. These appliances have double insulation.

Safety checks and safe working practices when using a mains powered tool

• Power tools must be fitted with guards and safety switches; they are extremely hazardous when used improperly. ... Never carry a tool by the cord or hose. Never yank the cord or the hose to disconnect it from the receptacle. Keep cords and hoses away from heat, oil, and sharp edges.

Hazards and dangers of extension cords

• Why are extension cords a safety hazard? If the extension cord is covered, heat is unable to escape and could result in a fire. Make sure extension cords are visible and if at all possible, not running across highly trafficked areas. They can be a trip hazard for people walking through the area.

Safe Use of extension cords

• Never remove an extension cord's grounding pin to fit into a two-prong outlet.

• Avoid powering multiple appliances with one cord.

• Never use indoor extension cords outdoors.

• Don't plug multiple cords together.

• Don't run extension cords under rugs or furniture.

• Never tape extension cords to floors or attach them to surfaces with staples or nails.

• Don't bend or coil cords when they're in use.

• Cover unused cord receptacles with childproof covers.

• Stop using extension cords that feel hot to the touch.

General PPE when using mains powered tools 

• Types of PPE that provide physical protection (with regards to power tools and machinery) mainly pertains to work gloves and safety boots. These two are highly recommended in combination with fitted full-body clothing. Bump caps and safety helmets are also available, but are not a necessity for power tool safety.