Lights dim when refrigerator is on

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SUMMARY

In older houses, the dimming of lights when a refrigerator starts is due to the high initial electrical load required to start the motor, which contrasts with the steady current drawn by an electric heater. This phenomenon highlights the difference between the transient load of a motor during startup and the constant load of a resistive heater. Additionally, a motor can act as both a motor and a generator simultaneously; it converts electrical energy into kinetic energy and can also convert kinetic energy back into electrical energy through induction. Generators, on the other hand, produce electrical forces that oppose the applied kinetic forces, affecting their efficiency and operation.

PREREQUISITES
  • Understanding of electrical load concepts
  • Familiarity with motor and generator principles
  • Knowledge of induction in electrical systems
  • Basic electrical circuit analysis
NEXT STEPS
  • Research the electrical load characteristics of AC motors
  • Study the principles of electromagnetic induction in motors and generators
  • Learn about the effects of starting current on household electrical systems
  • Explore the relationship between mechanical and electrical energy in electromechanical systems
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Electrical engineers, homeowners with older electrical systems, and anyone interested in understanding the dynamics of motors and generators in household appliances.

gillgill
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1. In older houses, when a refrigerator starts up, the lights may dim briefly. When an electric heater is turned on, the lights may stay dimmed as long as it is on. Explain the difference.

2. Explain what is meant by the statement "a motor acts as a motor and generator at the same time." Can the same be said for a generator?

thanks
 
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gillgill said:
1. In older houses, when a refrigerator starts up, the lights may dim briefly. When an electric heater is turned on, the lights may stay dimmed as long as it is on. Explain the difference.
This question relates to the electrical load in a) starting up a motor compared to b) maintaining a constant heavy current through a resistance. It seems to be asking: why does the motor in the fridge draw more power when starting up and much less power afterward?

2. Explain what is meant by the statement "a motor acts as a motor and generator at the same time." Can the same be said for a generator?
A generator transfers kinetic energy into electrical energy by 'induction'. Does the motor, which turns electrical energy into kinetic energy by 'induction', also transfer some of that kinetic energy back into electrical energy? How? I think that is what the question asks.

As for the second part, does a generator produce electrical forces that try to stop or reduce the applied kinetic or turning forces?

AM
 
ok...can u explain why?
 

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