TB8 Electrical Hazards

Question 1

TB 8 Electrical Hazards

Amps

• Current flow, or electro flow
• it is what flows on a wire or like water flowing down a river

Answer 1

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Question 2

TB 8 Electrical Hazards

Volts

• voltage is the difference in electrical potential between two points in a circuit.
• it is the push or pressure behind current flow through a circuit

Answer 2

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Question 3

TB 8 Electrical Hazards

Kilovolts
- the measure of 1000 volts. Commonly used by LADWP

Answer 3

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Question 4

TB 8 Electrical Hazards

OHMS

• Ohm is a measurment of resistance; comparable term in water hydraulics would be friction loss
• resistance determines how much current will flow through a component.
• resistors are used to control voltage and current levels
• a very high resistance allows a small amount of current flow

Answer 4

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Question 5

TB 8 Electrical Hazards

Ohms law

• watts= ampsxvolts
• amps= watts divide by volts
• volts= watts divide by amps

Answer 5

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Question 6

TB 8 Electrical Hazards

Extremely high voltage in excess of how many volts?

High voltage from ___ to ___

High voltage usually found in customer distribution system
Referred to as a primapry circuit voltage or “primaries”
LADWP system the primary distribution lines are usually 4.8kv

Answer 6

Extremelly high voltage is excess of 60,000 volts

High voltage is from 600-59,999 volts

Question 7

What is low voltage?

Answer 7

Usually below 600 volts.

Its called secondary circuit voltage and referreed to as a “secondary”

Question 8

TB 8 Electrical Hazards

Electricity fire hydraulics

Conductor=hose
Current=water
Volatge=pressure
Amperes=GPM
Ohms=friction loss

Answer 8

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Question 9

TB 8 Electrical Hazards

Overhead communication wires can normally be found on the lowest level of the power pole can be energized with up to 50 volts.

Answer 9

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Question 10

TB 8 Electrical Hazards

Responding to electrical emergencies.

• spot apparatus and have personnel maintain at least one span (the distance between two poles) from the affected wire or pole.
• if the pole is damaged do not count the damaged pole.
• be alert for energized exposures such as fences
• deny entry using fire line tape.
• make certain that the conductors are cleared and safe or that you are properly relived.

Answer 10

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Question 11

TB 8 Electrical Hazards

Street lights

• 120-6150 volts or more
• DWP consideres them energized with high voltage at all times

Answer 11

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Question 12

TB 8 Electrical Hazards

Distribution/substation fires

• in case of rescue, have victim remain stationary until LADWP gives clearance for rescue
• protect exoposures until assured by water and power representative that the power is cut off.
• do not put water on electrical equipment unless directed by DWP
• extinguish small electrical fires with dry chem or carbon dioxide.
• utilize the 30/33/100 rule
• 30 degree fog pattern, 33 feet from energized source, min 100 psi to nozzle.

Answer 12

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