Electrician Safety Flashcards
NCCR 26102-23, Delmar's Section 1, Class 3
What is the minimum amperage where death is possible from asphyxiation?
50-60 mA
What is the range where electrical tingling can be felt?
1-3 mA
What range is electric shock painful?
5-10 mA
What range is electric shock very painful and induce loss of muscle control?
20 - 40 mA
What range does electric shock affect breathing?
40 - 60 mA
What range is electric shock probably deadly from fibrilation?
100 mA
What are OSHA’s focus four?
- Fall Hazards
- Electrical hazards
- Caught-in or -between hazards
- Struck-by hazards
What is the demarcation between high and low voltage?
1,000V
What does GFCI stand for?
Ground fault circuit interruptor
What is the approximate resistance of a human body?
500 Ω for each arm and leg
100 Ω for the torso
What are electrical burn?
Occur when current flows through the body and creates heat internally.
What are arc burns?
Occur at the point of an arc.
What are thermal contact burns?
Occur when a molten object is thrown into someone from an electric arc blast.
What are the different parts of an electric arc blast?
- Sound and pressure waves
- Intense light
- Shrapnel
- Vaporized copper
- Molten metal
- Hot air
What table in NFPA 70E details the limited approach boundary for live AC parts?
130.4(E)(a)
What is a limited approach boundary?
The closest you should physically approach a live circuit component?
What document describes arc-flash hazard warnings?
NEC Section 110.16
What are the different limited approach boundaries for the different voltage ranges?
50V to 750V: 3’ 6”
751V to 15kV: 5’ 0”
15.1 kV to 36 kV: 6’ 0”
36.1 kV to 121 kV: 8’ 0”
138 kV to 145 kV: 10’ 0”
161 kV to 169 kV: 11’ 8”
230 kV to 242 kV: 13’ 0”
345 kV to 362 kV: 15’ 4”
500 kV to 550 kV: 19’ 0”
765 kV to 800 kV: 23’ 9”
What is a qualified persons?
People who have the necessary training or certifications and have demonstrated their knowledge and ability to resolve problems related to the work or project.
What is a competent person?
Workers who can identify hazards and take corrective action necessary to address them.
What is the procedure to verify circuits are safe?
Step 1: Make sure the circuit is properly locked out and tagged
Step 2: Confirm the test instrument is working by testing it on a known energized source.
Step 3: Test the line you think is dead
Step 4: Confirm the test instrument is working by testing it on a known energized source.
What is the hierarchy of risk controls?
Elimination
Substitution
Engineering Controls
Awareness
Administrative Controls
PPE
What document provides rules for PPE training?
CFR 1910.132(f)(1)
What document provides rules for PPE design standards?
CFR 1910.137(a)
What document provides rules for PPE safeguards regarding electrical hazards?
CFR 1910.335
What rating is a Class E hard hat?
20,000VAC for three minutes
What rating is a Class G hard hat?
2,200VAC for one minute
What is type 1 rubber protective equipment?
Created from vulcanized natural or synthetic rubber.
Flexible but easily damaged.
What is type 2 rubber protective equipment?
Ozone resistant equipment made from any elastomer or combination of elastomeric compounds.
Very stiff.
What are the colors of the different rubber protective equipment classes?
00: beige
0: red
1: white
2: yellow
3: green
4: orange
What are the different voltage ratings for the different rubber protective equipment classes?
00: 500VAC/750VDC
0: 1,000VAC/1,500VDC
1: 7,500VAC/11,250VDC
2: 17,000VAC/25,500VDC
3: 26,500VAC/39,750VDC
4: 36,000VAC/54,000VDC
What are the steps to inspect and test rubber gloves?
Step 1: Verify inspection date and voltage rating
Step 2: Visually inspect for damage
Step 3: Trap air inside rolling the wrist portion
Step 4: Squeeze glove to expose cracks, cuts, and defects
Step 5: Listen for any leaking air
What are hot sticks used for?
disconnecting and connecting switches
removing and inserting fuses
applying and removing temporary grounds
What is the construction of a hot stick?
Two parts: head or hood. Made of metal or hardened plastic. & insulating rod. Made of wood, plastic, laminated wood or other insulating material
How should you store hot sticks?
hand them vertically on a wall and away from sunlight or petroleum products.
What documents cover electrical safety related work practices?
29 CFR 1910.331 through 1910.335
What size hole required cover or guardrail?
2”
What are the basic attitudes and precautions?
All electrical work must comply with NEC, NFPA 70E and OSHA standards
Post hard hat areas and wear hard hats correctly
Wear safety shoes
Wear safe, well-fitted clothing. Avoid clothing with exposed metal
Wear safety glasses with full side shields
Use double-insulated or properly grounded tools
Use three-wire extension cords and protect them from damage
Use safe lighting and lamps
All 125V, single phase, 15A, 20A, and 30A receptacle outlets must be ground fault protected
Properly mark all points with purpose and voltage.Steps
What are the steps to replace a fuse?
Step 1: Put on PPE
Step 2: Turn off the power=
(For voltage over 1,000; step 2b: unlock the fuse department)
Step 3: Verify fuses are de-energized
Step 4: Remove blown fuse (use hot stick if voltage over 1,000)
Step 5: Install the new fuse (use hot stick if voltage over 1,000)
Step 6: Turn the power back on
Steps for a Lock Out Tag Out (LOTO)?
Step 1: Notify all authorized and affected personnel
Step 2: shut down equipment using normal procedures
Step 3: Lock out and test that it cannot be moved back on
Step 4: Each authorized employee must lock and tag the switches in the open position.
Step 5: Perform an on-off-on test to ensure the circuit is off
Step 6: Attach the equipment to ground to dissipate stored energy
Step 7: Retest if you leave the area and return
What are the steps to restore energy after a lock out, tag out (LOTO)?
Step 1: Account for all personnel and tools. Remove all tools from the equipment
Step 2: Completely reassemble and secure the equipment.
Step 3: Replace and/or reactivate all safety controls
Step 4: Remove locks and tags from isolation switches
Step 5: Notify all affected personnel that the LOTO is finish and the equipment is about to be re-energized
Step 6: Turn switches back on to restore energy
Who is allowed within a restricted approach boundary?
Only qualified persons using PPE can enter and work inside.
What is rule-based mode?
Performing work using rules and procedures
What is knowledge-based mode?
Performing work using knowledge and past experience.
What is skill-based mode?
Performing work using their own skill
How much higher should a ladder be above it’s bearing point?
3’
How far should the base of a ladder be from the resting point?
One forth the length of the working distance
What does MSDS stand for?
Material safety data sheet
What are the guidelines for trenches and where is the OSHA Standard?
- Do not walk close to trenches unless it is necessary.
- Do not jump over trenches
- Place barricades around trenches
4 Use ladders to enter and exit trenches
Standard 1926(P)(c)
What are the general rules regarding confined spaces?
- Have an outside person monitoring the workers inside. They hove voice and visual contact all all times as well as air sample readings, and gas levels
- The outside person should never enter the space but should contact emergency personnel if needed.
- Only operate equipment and tools that have been approved for the atmosphere inside the confined area
- The workers inside should wear harnesses and lanyards to allow them to be pulled to safety.
What are the general rules for safety harnesses?
A 6’ rope should be attached to the lanyard.
Harnesses should be worn:
1. When working more than 6’ above the ground or floor
2. When working near a hole or drop-off
3. When working on high scaffolding
What are the four classification of fires?
A: Fire from common combustible materials such as wood or paper.
B: Fires from grease, combustible liquids, or gases.
C: Electrical fires.
D: Burning metal
Why should you try to work on electrical systems with one hand?
In case you get shocked, the electricity will travel through your chest and heart if you use both hands.
What does GFCI stand for?
ground-fault circuit interrupter
What document lists requirements for grounding electrical systems?
NEC 250
What is one of the leading causes of electrical fires?
Poor connections
How many milliamperes of current will trigger a GFCI?
~5mA
What are AFCIs and what do they do?
Arc-Fault Circuit Interrupters
They protect against fires by
Where are AFCIs required according to the NEC?
On all 120V, single-phase, 15 and 20 amp circuits inside dwellings supplying power to family rooms, dining rooms, living livings, bedrooms, closets, hallways and similar rooms or areas.
