Page 1 of 2 12 LastLast
Results 1 to 13 of 14
  1. #1
    Join Date
    Aug 2009
    Location
    Oxnard, Calif.
    Posts
    44

    fuses and circuit breakers

    What is the advantage of fuses over circuit breakers?

  2. #2
    Join Date
    Jan 2004
    Location
    PA
    Posts
    68,773
    Breaker protects the wire.
    Fuse protects the equipment.

    You have the post count, apply for pro membership.
    Contractor locator map

    How-to-apply-for-Professional

    How many times must one fix something before it is fixed?

  3. #3
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    19,523
    Quote Originally Posted by beenthere View Post
    Breaker protects the wire.
    Fuse protects the equipment.
    That's interesting. You have given me something to think about.

    Hmmm.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







  4. #4
    Join Date
    Jul 2008
    Location
    Denver, CO
    Posts
    4,229
    Some breakers are designed to protect the equipment as well. Leiberts for instance will have an odd ball size breaker like 32 amps. Yet they are still protected by fuses. Interesting.

  5. #5
    Join Date
    May 2000
    Location
    Urbandale IA. USA
    Posts
    4,962
    I think it matters MORE WHERE the protection is located.
    Circuit Breakers are located IN the distabution pannel, while Fuses are located in the disconnect pannel.
    One protects the equipment, while the other protects the wire.
    That having been said, what if the fuses are in the dist. pannel, and the circuit breaker is in the disconnect? I have seen this done.
    Those who dance, appear insane to those who do not hear the music.
    Those who believe, appear ignorant to those who do not know God.

  6. #6
    Join Date
    Feb 2005
    Location
    Dothan, Al
    Posts
    3,453
    Quote Originally Posted by Royster88 View Post
    What is the advantage of fuses over circuit breakers?
    The only advantage is that you can get fuses at a lower amp rating than breakers, which will allow for 'closer' protection of equipment.
    There is not much difference between a dual acting fuse & a circuit breaker. HOwever, a one-time fuse & a circuit breaker are different in their ability to 'closely' protect a circuit.

    All breakers & fuses, in distribution panels, are designed to protect the conductors.
    All breaker & fuses in disconnects or within the equipment are sized for equipment protection.

    Richard

  7. #7
    Join Date
    Nov 2006
    Location
    Southeastern Pa
    Posts
    19,523
    IMHO...

    The most important aspect of protection is the detection of the high current condition and the reaction time of the protective device.

    An ideal situation would be a device that prevented the wiring from exceeding its temperature limit while reacting to a high current draw from the equipment in a time frame that helped to prevent further damage.

    Yes, fuses are available in increments that more closely follow the needs of a particular piece of equipment.
    [Avatar photo from a Florida training accident. Everyone walked away.]
    2 Tim 3:16-17

    RSES CMS, HVAC Electrical Specialist

    AOP Forum Rules:







  8. #8
    Join Date
    Aug 2009
    Location
    Griffin, Georgia
    Posts
    564
    fuses and breakers protect the same thing. it basically comes down to application. In some places it is better to use a fuse over a breaker. It also depends on what type of fuse you use; one time, dual element time delay, so on. I typically use fuses in disconnects on commercial units in some buildings i maintain. In this example one circuit that is sized large enough for 2 units can be broken down with fuses to protect the individual equipment.

  9. #9
    Join Date
    Feb 2005
    Location
    Dothan, Al
    Posts
    3,453
    Quote Originally Posted by jbcrane View Post
    fuses and breakers protect the same thing. it basically comes down to application. In some places it is better to use a fuse over a breaker.
    Can you give an example of when a fuse is BETTER than a breaker??

    It also depends on what type of fuse you use; one time, dual element time delay, so on. I typically use fuses in disconnects on commercial units in some buildings i maintain. In this example one circuit that is sized large enough for 2 units can be broken down with fuses to protect the individual equipment.
    Why can't a circuit breaker be used here, just as easily & with the same protection.

    In case you coudn't guess, I generally prefer breakers to fuses. Generally, the only time I use fuses is when the circuit I want to protect is too small ( current ) for a breaker.

    Richard

  10. #10
    Join Date
    Sep 2007
    Location
    SW Ohio
    Posts
    233
    I sometimes see disconnects with breakers for AC's but I never see them for sale like this anywhere. Anyone else ever run across them?

  11. #11
    Join Date
    Oct 2003
    Location
    Washington
    Posts
    7,405
    I would think frying a transformer or circuit board would happen a lot quicker than what it would take to cook a wire.

    That being said, I believe that a breaker is not sufficient enough to protect equipment and/or equipment components. By the time the breaker is tripped the damage has already been done to such sensitive devices. Am I wrong?

  12. #12
    Join Date
    Nov 2005
    Location
    sacramento calif.
    Posts
    1,191
    Quote Originally Posted by cjett View Post
    I sometimes see disconnects with breakers for AC's but I never see them for sale like this anywhere. Anyone else ever run across them?

    i see them alot but only on 40 yr. old equipt. it's the evolution of what code calls for.
    breakers and fuses both open faster the higher the spike over ampacity rating of said device. thats how you know its a shorted compressor when you find "both" fuses open in a disconnect.
    i was born under a wandrin star.

  13. #13
    Join Date
    Aug 2009
    Location
    Griffin, Georgia
    Posts
    564
    Quote Originally Posted by bornriding View Post
    Why can't a circuit breaker be used here, just as easily & with the same protection.

    In case you coudn't guess, I generally prefer breakers to fuses. Generally, the only time I use fuses is when the circuit I want to protect is too small ( current ) for a breaker.

    Richard
    I use breakers in main panels. I typically use fuses for retrofitting control circuits. If it is a new circuit I am putting in I use a breaker that I can set to what amp rating I need. Alot of the time on new installs if the size of the over current is unknown I will run a larger than required circuit and fuse it down. Pretty much it depends on the independent application for me.

Page 1 of 2 12 LastLast

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
Comfortech Show Promo Image

Related Forums

Plumbing Talks | Contractor Magazine
Forums | Electrical Construction & Maintenance (EC&M) Magazine
Comfortech365 Virtual Event