*TB 8- Electrical Hazards Flashcards
Terminology: The push or pressure behind current flow through a circuit is know as?
Volts
Terminology: _______ determines how much current will flow through a component.
Ohms
Amps x volts = ?
Watts (power)
High voltage is ranges from _____ to _____. Also referred to as “primaries”
600 to 59,999v
Low voltage is usually below _____ volts also referred to as “secondaries”
600v
Extremely high voltage is considered in excess of ______ volts
60,000v
All voltages above ________ volts are referred to as transmission voltages.
69,000v
Sub-transmission lines are considered to have __________ volts
34,500v
At a distribution station, electricity is received at ______ volts and stepped down to _____ volts
- 34,500v
2. 4,800v
Lines that carry 4,800 volts and run from the distribution stations to the neighborhood it feeds are known as what “type” of power lines?
primary lines or “primaries”
A receiving station takes high voltage from transmission lines and steps the voltage down to what?
34,500 volts
A ___________ is designed to reduce the voltage in the system to a voltage usable by the consumer.
Transformer
Pole-mounted transformers are installed on 4,800v circuits and step the voltage down to _____ volts
120/240 volts
Underground electrical lines can be found in conduits or ducts and are identified by warning signs labeled ______
UG (underground)
Electrical distribution lines placed directly in the ground are designated as _________
DB (direct buried)
High voltage capacitors are dangerous because?
- They can hold a charge for weeks even if power was shutdown to the circuit
- Contain dangerous chemicals
________ are appliances which will prevent the flow of electricity and provides support to the conductor.
Insulators
Insulators are mostly made of _____ or _____
Glass or porcelain
The service connection that uses three conductors twisted around each other is know as a _______
Triplex
The 3 most effective methods of identifying high voltage on a pole are?
- High voltage sign on cross arms
- Size and shape of insulators (large = high volts)
- Distance between conductors (wires)
What are the four main types of electrical injuries?
- Electrocution
- Electrical shock
- Burns
- Falls
Firefighters responding to emergencies involving electrical equipment must wear what kind of PPE’s?
Full turnouts with hood and firefighting gloves
There are two main methods for de-energizing a building are?
- Throw the main switch or breaker switched at electrical panel
- Cut wires with LAFD equipment
Besides wearing full firefighting turnouts while shutting down power at the electrical panel, what else SHALL be worn?
Eye protection, consider scba face piece
Is the LAFD able to cut high voltage wires in the case of an emergency?
No, contact MFC to have DWP respond
Aerial ladders must be kept at least _____ feet away from all power lines and devices.
10ft
The aerial ladder shall not work in violation of the 10-foot rule from electrical wires unless?
Participating in a rescue attempt