Full Answer
What is the purpose of guarding electrical equipment with exposed parts operating at 50 volts or more select the best option?
A person must be exposed to a potential difference of 50 volts or more for a shock hazard to exist. A person might be exposed to hazards associated with an arcing fault even when the conductor is guarded. A guarded conductor protects a person from exposure to shock or electrocution but not to arc flash hazards.
What is the purpose of guarding electrical equipment?
The purpose of machine guarding is to protect the machine operator and other employees in the work area from hazards created during the machine's normal operation. This would include hazards of concern such as: ingoing nip points, rotating parts, reciprocating, transversing, and/or flying chips & sparks.
What is the voltage of live parts of electrical equipment that must be guarded against for accidental contact?
50 voltsResponse: The provision in question, 29 CFR 1910.303(g)(2)(i), generally requires "live parts of electric equipment operating at 50 volts or more" to be "guarded against accidental contact by use of approved cabinets or other forms of approved enclosures" or by other specified means.
What is the OSHA standard for electrical safety?
The OSHA Standard For Electrical Systems The 1910.303 standard covers electrical installation practices that are critical to ensure employee safety and maintain equipment integrity. All electrical installations must meet or exceed all applicable OSHA regulations as well as recognized consensus codes.
What is the purpose of guarding electrical equipment with exposed parts operating at 50 volts or more quizlet?
Live parts of electrical equipment operating at 50 volts or more may be guarded against accidental contact by putting them at an elevation of eight feet or more above the floor or other working surface and installed so as to exclude unqualified persons.
How are electrical live parts being guarded?
(A) Live Parts Guarded Against Accidental Contact By location in a room, vault, or similar enclosure that is accessible only to qualified persons. By permanent, substantial partitions or screens arranged so that only qualified persons have access to the space within reach of the live parts.
Why is 50V a safe touch voltage?
This low power level is the reason why low-voltage (<50V) shocks have never been fatal — there is not enough electrical energy available to disrupt bodily functions.
When guarding live electrical parts guarding may be provided by location room balcony or platform or by elevation eight feet or more above the working surface?
Guarding of live parts. By elevation of 2.44 m (8.0 ft) or more above the floor or other working surface. In locations where electric equipment is likely to be exposed to physical damage, enclosures or guards shall be so arranged and of such strength as to prevent such damage.
What is the minimum clearance between a crane and any power line rated at 50 kV or below?
10 feet(i) For lines rated 50 kV. or below minimum clearance between the lines and any part of the crane or load shall be 10 feet; (ii) For lines rated over 50 kV., minimum clearance between the lines and any part of the crane or load shall be 10 feet plus 0.4 inch for each 1 kV.
Why is electrical safety important?
Electrically powered equipment can pose a significant hazard to workers, particularly when mishandled or not maintained. Many electrical devices have high voltage or high power requirements, carrying even more risk.
What does OSHA consider high voltage?
OSHA considers all voltages of 50 volts or above to be hazardous to employees regardless of whether the electric current is AC or DC since the current can cause serious injury.
What are the electrical safety guidelines?
10 Electrical Safety Tips for the WorkplacePrevent All Potential Contact With Live Electrical Current. ... De-energize Equipment and Use Lockout/Tagout. ... Ensure Safe Use of Electrical Equipment. ... Install Proper Physical Barriers Around Electrical Hazards. ... Beware of Conductive Tools and Cleaning Materials.More items...•
What is the purpose of the safety guards?
protective measures consisting of the use of specific technical means, called safeguards (guards, protective-devices), to protect workers from hazards that cannot be reasonably removed or sufficiently limited by design.”
Why safety guard is important in any machine or hand tool?
The safeguards prevent workers hands, arms and other body parts from making contact with dangerous moving parts. Special guards, enclosures or personal protective equipment have been provided, where necessary to protect workers from exposure to harmful substances used in machine operations.
What is machine guarding OSHA?
Machine guarding. 1910.212(a)(1) Types of guarding. One or more methods of machine guarding shall be provided to protect the operator and other employees in the machine area from hazards such as those created by point of operation, ingoing nip points, rotating parts, flying chips and sparks.
Why safety guards is important in any machine or hand tool Explain your choice within the provided space?
They may restrain or withdraw an operator's hands from the danger area. They may require both hands on a control, therefore keeping both hands out of the danger area. They may also provide a synchronized barrier with the machines operating cycle to prevent entry into the danger area.
Why do you need to lock equipment at 50 volts?
To avoid the risk of accidental shock, live electrical components operating at 50 volts or more must be guarded with covers or other permanent barriers to prevent accidental contact by workers and their tools. Equipment can also be locked behind an enclosure, in a room, or at an elevated height.
What is machine guarding?
Machine guarding provides a means to protect humans from injury while working nearby or while operating equipment. It is often the first line of defense to protect operators from injury while working on or around industrial machinery during normal operations.
How far away from power lines should equipment be?
The Occupational Safety and Health Administration (OSHA) requires that equipment be kept at least 10 feet away from power lines with voltages up to 50kV. For lines with voltages higher than 50kV, the required distance is even greater (see below).
What is high voltage?
OSHA does not have a consistent definition for high voltage—OSHA standard 1910.304 (g) (9) for grounding fixed equipment refers to fixed equipment as anything higher than 1,000 volts, whereas other OSHA standards such as 1910.303 (h) (5) (ii) refer to high voltage as being above 600 volts.
Answer
Electrical equipment should be guarded with exposed parts operating at 50 volts or more to avoid the accidental shock and also to prevent accidental contact by workers and their tools.
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What is the requirement for live parts of electric equipment operating at 50 volts?
Response: The provision in question, 29 CFR 1910.303 (g) (2) (i), generally requires "live parts of electric equipment operating at 50 volts or more" to be "guarded against accidental contact by use of approved cabinets or other forms of approved enclosures" or by other specified means. The guarding requirement does not distinguish between AC and DC voltages. Therefore, the requirement applies to live parts operating at 50 volts or more AC or DC. 1
What is OSHA standard number 1910.303?
Standard Number: 1910.303 (g) (2) (i) OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed.
How many volts does a DC welder use?
3 Although the second abstract does not reference a specific voltage, the open circuit voltage on a DC welder is between 50 and 100 volts.
Is 50 volts DC dangerous?
You point out in your letter that some consensus standards consider live parts operating between 50 and 60 volts, DC, to be non-hazardous under certain circumstances. However, OSHA considers all voltages of 50 volts or above to be hazardous. Electric current, not voltage, passing through the human body causes injury, and the amount of current passing through an object depends on the resistance of the object. As explained in Appendix C to 29 CFR 1910.269, theinternal resistance of the human body is 500 ohms, which is the minimum resistance of a worker with broken skin at the point of contact. The current through 500 ohms from a live part energized at 60 volts would be 120 milliamperes. This level of current, either ac or dc, is sufficient to cause serious injury. 2