Safety Overview

Question 1

Most Electricians (do not) work with electricity

Question 2

CAT IV (four) = Best

Question 3

Bigger distance, need shorter probe

Question 4

Safety

Test known circuit before unknown.

What makes a circuit dangerous?
-amount of volts
-amount of current (most crucial)
-condition of skin
-path it takes through our body
-AC or DC (AC more dangerous)

Question 5

Occupational Health and Safety (OSHA)

-provincial not federal

-Employer responsible for providing safe environment
-employee identify what’s not in compliance

Question 6

methane - poop and rots (come from)

use for generators (methane)

Question 7

Confined space

Why Confine space is dangerous?
-heat (outside)
-lack of oxygen (biggest)
-inhale chemical fumes

Safety measures?
-there must be guy outside (guard) - must never enter (confine space)
-lash (roper) to other guy (harness)
-permit (trained) - may need burning permit

Question 8

Lockout & Tagout Procedures

Purpose?
-prevent energizing equipment (or by other people - by mistake)
-switches
-circuit breakers
-valves (block)

-lock with padlock (your own) - keep key to urself

6, 11, 16 class

Question 9

Safety Harness (need 6 foot rope (lanyard)

For what?
-when above 6 feet
-near hole or drop off
-high scaffolding
*manlift

Question 10

Ladder and Scaffold
4:1 out of 4 out 1 or 75 (76) degrees

Ladders
-made of fibre glass or aluminium (conductive though) combination fibreglass
-don’t really use wood anymore (heavy when wet - Slippery)
-need extra 3 feet on top
20 foot long (height) & 5 feet away (4:1) (from the base)

Never step on top of ladder (also 2 steps down)

Question 11

Different types of fires

AFCI (arc fault circuit interruptor)
GFCI (ground fault circuit interruptor)

Question 12

Types of scaffolds:

-Rolling Scaffolds
-Hanging or Suspended Scaffolds

Question 13

Safety harness:
-upper body with leg, shoulder, & chest straps & (secured above the worker)

Question 14

Fires

Different materials require different amounts of heat for combustion take place.

Oxygen - if fire is denied oxygen, it will extinguish
-oxygen must be present for combustion to take place

Question 15

Fire are divided into four classes: A,B,C, and D

Class A - common combustible materials - wood and paper
.
-used (often) water to extinguish fire by lowering temperature of fuel

Question 16

Fire are divided into four classes: A,B,C, and D

Class B - involves fuels - grease, combustible liquids or gases

-employ (generally) carbon dioxide (CO2) to greatly lower temperature of fuel & deprive oxygen

-use for electrical fires (do not coat it with dry powder - destroy surrounding equipment)

Question 17

Fire are divided into four classes: A,B,C, and D

Class C - involves energized electrical equipment
-use (usually) dry powder to smoother the fire

Many fire extinguishers used on multiple types of fires
-an extinguisher labelled ABC could be used on any of the three classes of fire

Never use an extinguisher not rated. - using class A extinguisher water on electrical fire can be fatal

Question 18

Fire are divided into four classes: A,B,C, and D

Class D - consist of burning metal. - water can increase fire

-uses a powder placed on top of the burning metal, forms a crust to cut off the oxygen supply terminal.

-some powders only stop the fire from spreading to other combustible materials

Greatest cause of electrical fires - poor or loose connections
-creates resistance, resistance causes heat

Question 19

Fires

Electricity is a form of pure energy
- the electrical unit (watt) - measures the amount electrical energy converted into some other forms

When resistance is present electrical energy is converted into thermal energy or heat
-soldering irons - range from 15 to 30 watts

The higher the current (higher current load), the more a small resistance increase can cause extreme amount of heat

P = I power of 2 x R
P = 25 x 25 x 0.25
P 156.25 Watts

Question 20

Poor connection can cause the metals of the conductor & terminal to oxidize & develop even more resistance (more damage) (melt & burn away conductor connected to terminal)

Question 21

Glove Safety

-test gloves once a year (rubber or leather gloves)
-don’t lend rubber or leather gloves (safety)
-1000 volts?
-12,000 volts (bigger gloves)(line workers) (BC Hydro) (Industrial)
-balloon test (test for rips) (Lab test)
-chemical break (use respirator) ( last only 3 - 5 minutes)

Question 22

Lockout & Tagout

-box padlock (cords or plugs)
-circuit breaker padlock (two kinds: screw & chip)
-large motor switch padlock
-switch cover (padlock)

Tag
-remember name, date (& time), and phone number

Question 23

Horseplay
-pushing
-throwing
-doing dangerous stuff near people

Question 24

2 mA - .002 - slight tingling
(50 mA) 40 mA - 200 mA - dangerous

100 - 200 mA (fibrillation)

Question 25

Ground fault circuit interuptor

-bathroom GFCI protected

-curling iron
-outdoor construction
-lawnmower (wet)
-trip one cycle

GFCI - must trip at 4 - 6 mA (or 5 mA)
-difference of 5 mA shut circuit down (opens circuit)

GFCI - swimming pools
-hot tubs
-protect life (electrocution)
-trips one cycle

Question 26

GFCI devices
-two buttons
-green indicator light
-circuit breaker style
-plug style (cheaper) - protects anything below besides receptacle

Ground fault extension (multi outlet)

Question 27

Arc-Fault circuit interruptor (AFCI’s)
-protected people (fire)

-sparks cause flames
-use all 120v, single phase, 15-20 A circuit

*National

Used faulty rooms, dining rooms, living rooms, dens, bedrooms, laundry rooms, recreation rooms, hallways, or similar rooms or areas

except kitchen & lighting

Expensive, AFCI looks like GFCI plug style
-can protect everything below
-but need installation for everything ($)

Question 28

Series arc fault - a loose screw or wire connection damaged

arc fault - funny waveforms
Normal switch turning on (spike for first wave form)

Need u-ground to push through plug - Tamper - resistant receptacle mainly close to ground or kitchen

Ground triggers break by - imbalanced neutral

Question 29

Identify Energy Sources:

Electrical
Mechanical (moving parts)
Pressure (gas, liquids)
Thermal (open, flame)
Stored energy
Hazardous

Question 30

Each person have own lock & key

never share

wedges - secondary isolation

Notify effected employees
-(clear of personnel, check everything is guarded)
-restart

Question 31

Scaffolds - safest elevated working platform to do electrical work

-adjustable feet on bottom sections to level the sections
-has two end sections are connected by X braces that form a rigid platform
-sections of scaffolding are stacked on top of each other to reach desired height

Question 32

Two types of Scaffolds - Rolling & Hanging or Suspended Scaffolds

Rolling scaffolds - used inside buildings - in areas that contain level floors
-equipped with wheels on the bottom section to permit moving it from one position to another
-the wheels have a mechanism that locks them after the scaffold is rolled to desired location

Question 33

Two types of Scaffolds - Rolling & Hanging or Suspended Scaffolds

Hanging or Suspended scaffolds - suspended by cables from support structure
-used on the side of buildings to raise & lower workers by using hand cranks or electric motors

X braces connect scaffolding sections together

Question 34

Ladder - two types straight & step ladders
-should check it’s load capacity regardless of the type of ladder used (found on side of ladder)

Common load capacities are:

91 kg (200 lbs)
113 kg (250 lbs)
136 kg (300 lbs)

Question 35

do not use a ladder that does not have enough load capacity to support your weight plus the weight of your tools & the weight any object your taking up the ladder with you.

Question 36

straight ladders - constructed by placing rungs between two parallel rails
-safety feet on one end that prevents ladder from slipping

Question 37

Step ladders - self - supported, constructed of two sections hinged at the top
-the front section has two rails & steps, the rear portion two rails & braces

do not use top ladder (unbalanced & falling)

Parts of step ladder
Ladder top, spreader, top step, and highest usable step

Question 38

Fires

fire need 3 things to burn - fuel, heat, & oxygen

Fuel - is anything that can burn - wood, paper, cloth, combustible dusts, & even some metals

Combustion temperature - if a fuel is below it’s combustion temperature it will not burn