Algebra For Electrical Workers

1
Algebra For Electrical Workers!

• International Brotherhood of Electrical Workers
• By Ron Hagen, IBEW Instructor
• March 20, 2007
• Rialto High School Algebra I Classes

2
Introduction

• Background
• Personal Background
• Labor Union Background
• Interesting Facts

3
Math in the Field

• Ohms Law
• Trigonometry

4
Vocabulary

• Amperage
• The amount of electrons that pass a given point
  in one second (Current flow).
• Voltage
• The potential to do work.
• Wattage
• The measure of the amount of power being used in
  a circuit
• Ohms Law for Amperage

5
Example

• Background
• Most houses have multiple electrical circuits.
  Each circuit usually goes through a 20 amp
  circuit breaker designed to prevent electrical
  fires or damage to electrical devices. The 20
  amp circuit breaker will disconnect the power to
  that circuit whenever the 20 amps are exceeded.
• Whenever Jose is playing video games and his
  sister is getting ready to go out, the circuit
  breaker trips and the power goes out. So Jose
  has to go outside to the breaker panel and flip
  the breaker back on so that he can start his
  video game all over.
• The Facts
• The 20 amp circuit in Joses bedroom also goes
  through his his sisters bathroom.
• Joses Nintendo Wii is 3 amps.

6
Example

• The Question
• If Jose is playing his Nintendo Wii (which uses 3
  amps) at the same time that his sister is getting
  ready, what is the maximum amount of power
  (wattage), at 120 volts, that his sister can use
  with her curling iron and her hair dryer and
  still keep the power from being disconnected by
  the 20 amp breaker?

7
Example

• The Question
• If Jose is playing his Nintendo Wii (which uses 3
  amps) at the same time that his sister is getting
  ready, what is the maximum amount of power
  (wattage), at 120 volts, that his sister can use
  with her curling iron and her hair dryer and
  still keep the power from being disconnected by
  the 20 amp breaker?
• The formula for Amperage is
• Using this formula and the above information the
  following inequality can be derived

8
Example

• Solution

• Joses sister must use less than or equal to 2040
  watts at a time if Jose wants his sister to keep
  the circuit under 20 amps so she doesnt mess up
  his video game and cut the power.

9
Guided Practice

• If Joses mom is watching her 4 amp High
  Definition 50 Inch Plasma TV also on the same
  circuit, then what is the maximum amount of power
  (wattage), at 120 volts, that his sister can use
  with her curling iron and her hair dryer and
  still keep the power from being disconnected by
  the 20 amp breaker?

• Joses sister must use less than or equal to 1560
  watts at a time if Jose wants his sister to keep
  the circuit under 20 amps so she doesnt mess up
  his video game and cut the power.

10
Independent Practice

• If Joses mom is watching her 4 amp TV and the 8
  amp microwave was also running on the same
  circuit, then what is the maximum amount of power
  (wattage), at 120 volts, that his sister can use
  with her curling iron and her hair dryer and
  still keep the power from being disconnected by
  the 20 amp breaker?

• Joses sister must use less than or equal to 600
  watts at a time if Jose wants his sister to keep
  the circuit under 20 amps so she doesnt mess up
  his video game and cut the power.

11
Hands-on

• Circuit Breaker Demo