Safety Overview Flashcards
Most Electricians (do not) work with electricity
CAT IV (four) = Best
Bigger distance, need shorter probe
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)
Occupational Health and Safety (OSHA)
-provincial not federal
-Employer responsible for providing safe environment
-employee identify what’s not in compliance
methane - poop and rots (come from)
use for generators (methane)
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
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
Safety Harness (need 6 foot rope (lanyard)
For what?
-when above 6 feet
-near hole or drop off
-high scaffolding
*manlift
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)
Different types of fires
AFCI (arc fault circuit interruptor)
GFCI (ground fault circuit interruptor)
Types of scaffolds:
-Rolling Scaffolds
-Hanging or Suspended Scaffolds
Safety harness:
-upper body with leg, shoulder, & chest straps & (secured above the worker)
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
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
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)
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
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
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
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)
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)
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
Horseplay
-pushing
-throwing
-doing dangerous stuff near people
2 mA - .002 - slight tingling
(50 mA) 40 mA - 200 mA - dangerous
100 - 200 mA (fibrillation)