Embed Size (px)
Citation preview
Electrical Safety 2: Checking Answers
Fuse
Electrical Safety 2: Checking Answers
FuseMelts if too much current flows
Protects against overloads and fires. Does NOT protect people against shocks
Electrical Safety 2: Checking Answers
Thermal circuit breaker
Electrical Safety 2: Checking Answers
Thermal circuit breaker
Switches off if too much current flows. Works using a little heater inside
Electrical Safety 2: Checking Answers
Magnetic circuit breaker
Electrical Safety 2: Checking Answers
Magnetic circuit breaker
Switches off if too much current flows. Works by a little electromagnet inside pulling a switch
Electrical Safety 2: Checking Answers
RCD
also called RCCBs or ELCBs
One brand is
“Power Breaker”
Electrical Safety 2: Checking Answers
RCD
also called RCCBs or ELCBs
One brand is
“Power Breaker”
Use these with lawn mowers and anything else outdoors
Switches off if the Live current and Neutral current are not equal
Protects people from shocks – switches off before a lethal current flows through you.
Electrical Safety 2: Checking Answers
Earthing
Electrical Safety 2: Checking Answers
Earthing
Normally this wire does nothing, but if there’s a fault the current goes this way instead of through me!
If a machine has a metal case, this wire connects the case to the ground
Electrical Safety 2: Checking Answers
Double insulation
Electrical Safety 2: Checking Answers
Double insulation
Plastic case, the machine has no exposed metal anywhere
Does not need an earth wire
Electrical Safety 2: Checking Answers1. When a fuse “blows”, I should fix the fault that caused it before I put in a new fuse because...
(a) the new fuse will also blow(b) to remove any danger
2. Circuit breakers are more convenient than fuses because...
they are easier to reset
3. Three appliances that need earthing:
Two appliances that do not need earthing:
e.g. fridge, freezer, computer, washing machine...
e.g. hairdryer, TV...
End
