Basic Electrical Flashcards
What voltage is LV below ?
and what voltage is HV above?
LV is Below 1000V
HV is above 1000V
What is AC ?
Is current that continually changes its direction in regulated periods/cycles.
Examples of AC include electricity that enters houses from the power lines to run domestic appliances.
What is DC ?
DC is an electrical current that flows in 1 direction only.
Examples of DC include anything battery powered, electricity in electrical circuits of motor vehicles, electricity from solar panels, trams and trains
What is Step- Voltage?
When feet are placed on different voltage rings, electricity equal to the flow of rings will flow through the body. Eg 800-600V = 200V flowing through body
What is Touch Potential?
When touching a wire or energised object while standing with feet on the same voltage ring, voltage equal to the difference
between the wire and the voltage ring will flow through the body.
1200V - 600V = 600V.
600 volts will pass through the
firefighter.
What is the safe approach distance for a fallen distribution line and a transmission line?
Distribution line - 8M
Transmission line - 20M
What are some indicators of dual power supplies on properties?
- Label on switchboard
- Label at POE
- Labelled isolator close to alternative supply source
- PV sticker on switchboard
What are some alternative power supplies?
Solar
Wind
UPS - Uninterrupted power supply
Battery’s
List 7 hazards that may be in a substation?
1 High Voltage cable and equipment
2 Confined Space
3 Compressed Gas
4 - PCBS in transformers & capacitors,
5 - Residual power in capacitors
6 - Oils used for cooling – use foam to extinguish
7- Stairs close to entry
8- Asbestos materials
What is Voltage?
Voltage is the force that causes the flow of electricity. It can be likened to water
pressure. It causes the electricity to travel through the circuit.
