Assalamualaikum , we
have given the new task for chapter 6. There are three members of this
group discussion , which is me, MUHAMMAD AIZUDDIN AKMAL BIN
ZALKAHA,MUHAMMAD HASIF AIMAN BIN IBRAHIM AND NUR AZAMULLAH BIN MOHAMED.
We are from group 'L.E.D.'
We are from group 'L.E.D.'
WHAT IS ELECTRICAL SAFETY?
-Electrical Safety. Electrical hazards can cause burns, shocks and electrocution (death). Assume that all overhead wires are energized at lethal voltages. Never assume that a wire is safe to touch even if it is down or appears to be insulated.
The defective insulation hazards
You need to be able to recognize that electrical shocks, fires, or falls result from these hazards:
Improper grounding. -The metal parts of an electrical wiring system that we touch should be grounded and at 0 volt.
Overloaded circuits. -Devices (for example, holiday lights or an often used electric heater) with long-term uses do count. A circuit isoverloaded if: A. The total load exceeds 1,800 watts for a 15-amp circuit. (120 volts x 15 amps = 1,800 watts.) Look for the amp rating of the circuit in tiny numbers on the circuit breaker switch or fuse.
Wet conditions. -If you touch a live wire or other electrical component while standing in even a small puddle of water you’ll get a shock.
Preventive measures in electrical safety
-Protection from direct contact.The physical prevention of contact with live parts by barriers, insulation, inaccessibility, etc. Additional protection in the event that a direct contact occurs, despite or due to failure of the above measures. This protection is based on residual-current operating device with a high sensitivity (IΔn ≤ 30 mA) and a low operating time. These devices are highly effective in the majority of case of direct contact.-Protection from indirect contact.
An indirect
contact refers to a person coming into contact with an
exposed-conductive-part which is not normally alive, but has become
alive accidentally (due to insulation failure or some other cause).
To create a safe working environment
- Lock out and tag out circuits and equipment
When two or more workers are working on different parts of a larger overall system, the locked-out device is first secured with a folding scissors clamp that has many padlock holes capable of keeping it closed. Each worker applies their own padlock to the clamp. The locked-out device cannot be activated until all workers have signed off on their portion of the project and removed their padlock from the clamp.
- Overload wiring by using the right size and type of wire.
=Electrical cords supplement fixed wiring by providing the flexibility required for maintenance, portability, isolation from vibration, and emergency and temporary power needs.
Flexible wiring can be used for extension cords or power supply cords. Power supply cords can be removable or permanently attached to the appliance.
=DO NOT use flexible wiring in situations where frequent inspection would be difficult, where damage would be likely, or where long-term electrical supply is needed. Flexible cords cannot be used as a substitute for the fixed wiring of a structure. Flexible cords must not be . . .
- run through holes in walls, ceilings, or floors;
- run through doorways, windows, or similar openings (unless
physically protected); - attached to building surfaces (except with a tension take-up
device within 6 feet of the supply end); - hidden in walls, ceilings, or floors; or
- hidden in conduit or other raceways.
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