Regarding Energy Saver.

Discussion in 'Homework Help' started by joshua, Oct 10, 2006.

  1. joshua

    Thread Starter New Member

    Oct 10, 2006
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    0
    I'm working with a company that deals with energy saver equipment. The main component for it is a capacitor bank. The question is how do i differ items of resistive/reductive load to inductive load ? From wat i understand, inductive loads are like motors. What about resistive/reductive loads ?? By the way is resistive and reductive the same thing ?
    Another question is how do i identify whether it's a leading or a lagging power factor ? The formula for real power is Real power (W) = Voltage(V) × Current consumed (A) × Power Factor.
    There is leading and lagging power factor with the value ( ex: 0.3 leading is good but 0.3 lagging will cause less efficiency and power loss) So how do i defy the real power as if i were to put 0.3 into the formula.. i'll be getting the same answer. Hopefully i'm not confusing people. Hope u guys can help. thanks.
     
  2. thingmaker3

    Retired Moderator

    May 16, 2005
    5,072
    6
    Resistive load examples include lights, heating elements, and most items with their own power supplies.

    For leading and lagging, let's ask "ELI the ICE man." Voltage (E) for an inductive load (L) leads current (I). Current (I) for a capacitive circuit (C) leads voltage (E).

    I'll have to let someone else handle "reductive loads." I don't know the term.
     
  3. joshua

    Thread Starter New Member

    Oct 10, 2006
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    Thanks alot bro for the explanation. Appreciate it alot.
     
  4. EEMajor

    Well-Known Member

    Aug 9, 2006
    67
    4
    Just a side note, not all motors are inductive. Synchronous motors act like capacitors. You will often find large rooms full of synchronous motors running, but not attached to anything, in industrial applications because they will help correct the power factor. It ends up being cheaper to run this extra motors then it would be if they were to go over there power factor limit.
    Anyway....like I said, just a little side note.

    Also another rule of thumb for leading/lagging, if capacitive reactance is larger then inductive reactance, you will have a leading power factor. If no capacitor, only inductors, you will have a lagging power factor. If all resistive, 0 power factor, and if inductive reactance is larger then capacitve reactance, you have lagging again. (obvious from first statement)

    I too, have to idea what "reductive" means with respect to electronics....Do you mean "INductive"???

    Have a good one...
     
  5. joshua

    Thread Starter New Member

    Oct 10, 2006
    4
    0

    ohh ok.. now i get a much clearer picture. Actually I read somewhere which mentioned about reductive loads. Maybe Reductive and Resistive are the same? Examples that they quoted were like water heater, iron and kettle. So from this explanation I feel it could be that they were refering to resistive loads.
    Anyone can confirm this ?

    Thanks alot bro for your explanation.
     
  6. EEMajor

    Well-Known Member

    Aug 9, 2006
    67
    4
    That would be my guess then, if they said kettles, hot water heaters and irons are "reductive" they must mean the same thing as resistive. Interesting, I have never heard of that before...
     
  7. joshua

    Thread Starter New Member

    Oct 10, 2006
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    0
    What will happen If you only have resistive loads and a capacitor in a system? Will you be paying higher bill ?
     
  8. EEMajor

    Well-Known Member

    Aug 9, 2006
    67
    4
    Typically (at least here in the USA) residential and small business customers pay the bill based on the true power or watts that are being used. Industrial applications are billed a flat monthly fee and then penalized if they hit a certain "Power Factor" anytime during the month. This penalty is usually large, so industry tries to keep their Power Factor low.

    The loads in your house are a mixture of all sorts of things, between all your electronics and lighting, toys, cooking equipment, applicances, etc, etc, you end up with some resistive, some capacitve and some inductive loading on your system.

    But for a home user, Power Factor doesn't really matter. You can alter it to change the way your meter reads ending up saving you money, but if you are not careful you can actually change it to make the meter go faster and bill you more! This is not only illeagle, but requires extensive electrical knowledge (I have no idea how exactly to do it, I'm more into the electronics side rather then the electrical side) and you need to buy some pricey equipment to do it, from what I understand.

    Long story short: If you are in your home or a small business, don't worry about power factor. If you are in industry, you will typically have an industrial electrician as part of your staff who will take care of the power factor for you in a legal way.
     
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