I need a time-delay Square D breaker for a new air compressor.

Discussion in 'Electrical Engineering' started by Guy Doucet, May 14, 2005.

  1. Guy Doucet

    Guy Doucet Guest

    SITUATION
    I have a 200 Amp electrical panel in my home. It's says QO Combination Load
    Center Cat QO-40M Ser T4.

    I built a garage a few years ago and brought a 12/3 wire to it which I had
    connected to a 20 Amp SquareD circuit breaker I bought.

    I have the following in my garage
    - garage door opener, 8 x 100Watt light bulbs, Table saw, Old Shop Vac,
    etc...

    I just bought a Delta Air Compressor but it popped my 20Amp breaker. Nothing
    else in the garage was on, except maybe the 60Watt light bulb in the garage
    door opener.

    So then I read in the compressor manual where I found the following
    specifications:
    - Voltage-Single Phase 120V/60Hz/1Ph
    - Minimum Branch Circuit Requirement 15 amps
    - Fuse Type Time Delay (circuit breaker is preffered)


    QUESTION
    How can I differentiate from a reqular SquareD circuit breaker and a Time
    Delay SquareD circuit breaker. There doesn't appear to be any indications on
    the breaker itself.

    Thanks for any and all information.

    G Doucet
    Guy Doucet, May 14, 2005
    #1
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  2. Guy Doucet

    Fred Guest

    Sounds like you should take a look at the motor amp rating and horsepower on
    that new compressor of yours.

    A compressor motor will draw up to three times its rated running amperage to
    start up. Could be up to 45 amps in your case depending on the motor
    horsepower.

    Have never heard of a "time-delay" circuit breaker???

    Fred

    "Guy Doucet" <> wrote in message
    news:4hrhe.12959$...
    > SITUATION
    > I have a 200 Amp electrical panel in my home. It's says QO Combination
    > Load
    > Center Cat QO-40M Ser T4.
    >
    > I built a garage a few years ago and brought a 12/3 wire to it which I had
    > connected to a 20 Amp SquareD circuit breaker I bought.
    >
    > I have the following in my garage
    > - garage door opener, 8 x 100Watt light bulbs, Table saw, Old Shop Vac,
    > etc...
    >
    > I just bought a Delta Air Compressor but it popped my 20Amp breaker.
    > Nothing
    > else in the garage was on, except maybe the 60Watt light bulb in the
    > garage
    > door opener.
    >
    > So then I read in the compressor manual where I found the following
    > specifications:
    > - Voltage-Single Phase 120V/60Hz/1Ph
    > - Minimum Branch Circuit Requirement 15 amps
    > - Fuse Type Time Delay (circuit breaker is preffered)
    >
    >
    > QUESTION
    > How can I differentiate from a reqular SquareD circuit breaker and a Time
    > Delay SquareD circuit breaker. There doesn't appear to be any indications
    > on
    > the breaker itself.
    >
    > Thanks for any and all information.
    >
    > G Doucet
    >
    >
    Fred, May 14, 2005
    #2
    1. Advertising

  3. Guy Doucet

    Guest

    Guy Doucet <> wrote:
    >I built a garage a few years ago and brought a 12/3 wire to it which I
    >had connected to a 20 Amp SquareD circuit breaker I bought.


    About how long is the run from the breaker panel to the garage?

    >I have the following in my garage
    >- garage door opener, 8 x 100Watt light bulbs, Table saw, Old Shop Vac,
    >etc...


    If all 8 light bulbs are on then you probably will pop the breaker if
    you try to run the compressor.

    >So then I read in the compressor manual where I found the following
    >specifications:
    >- Voltage-Single Phase 120V/60Hz/1Ph
    >- Minimum Branch Circuit Requirement 15 amps
    >- Fuse Type Time Delay (circuit breaker is preffered)


    >QUESTION
    >How can I differentiate from a reqular SquareD circuit breaker and a Time
    >Delay SquareD circuit breaker.


    The terseness of the label is a bit confusing. "Time delay" refers to
    the fuse type, not the breaker type. A better way to put it would be:

    ---
    If you use a fuse on the circuit for this compressor, use a time delay
    type fuse. A regular fuse will blow when the motor starts.

    Using a circuit breaker, instead of a fuse, is preferred.
    ---

    Nearly all circuit breakers that you're likely to encounter in your
    house are already "time delay". They are made this way for precisely
    your application: starting motors. Motors draw a lot more current when
    they start up than they do when they are running, but if the motor is
    working correctly, this high current draw only lasts for a few seconds.
    If the high current draw persists for longer than that, the breaker will
    trip.

    In a perfect world, the compressor would have a 15 amp breaker all to
    itself. One thing to check is that all connections on the circuit,
    starting at the breaker panel, are clean and tight. If you have a bad
    connection, the resistance of the circuit will go up, which will lower
    the voltage at the compressor motor. Within certain limits, the motor
    will attempt to draw more current to compensate, which might trip the
    breaker. If you have a voltmeter, you might be able to tell. Measure
    the voltage at an outlet in the garage with everything or nearly
    everything in the garage shut off, and note the reading. Then go around
    and turn on all the lights and maybe the vacuum, then with all that
    stuff running, take another reading at the same outlet. It will be
    lower than the first reading by a volt or two, but if it's 10 or 20
    volts lower, you have a problem - either a bad connection somewhere, or
    the 12/3 wire was too small for the distance between your garage and the
    breaker panel.

    If you used "push in" connections that did not require you to also
    tighten a screw, redo each connection like this, this time putting the
    wire under the screw head. Make sure all wire nuts are on tight, and
    so on.

    Warning: Electricity can kill you, so be careful. Get help from an
    electrician if needed.

    Matt Roberds
    , May 15, 2005
    #3
  4. Guy Doucet

    Guy Doucet Guest

    "Stephen B." <> wrote in message
    news:zcuhe.1199$...
    > "Guy Doucet" wrote
    > > SITUATION
    > > I have a 200 Amp electrical panel in my home. It's says QO Combination

    > Load
    > > Center Cat QO-40M Ser T4.
    > >
    > > I built a garage a few years ago and brought a 12/3 wire to it which I

    had
    > > connected to a 20 Amp SquareD circuit breaker I bought.
    > >
    > > I have the following in my garage
    > > - garage door opener, 8 x 100Watt light bulbs, Table saw, Old Shop Vac,
    > > etc...
    > >
    > > I just bought a Delta Air Compressor but it popped my 20Amp breaker.

    > Nothing
    > > else in the garage was on, except maybe the 60Watt light bulb in the

    > garage
    > > door opener.
    > >
    > > So then I read in the compressor manual where I found the following
    > > specifications:
    > > - Voltage-Single Phase 120V/60Hz/1Ph
    > > - Minimum Branch Circuit Requirement 15 amps
    > > - Fuse Type Time Delay (circuit breaker is preffered)
    > >
    > >
    > > QUESTION
    > > How can I differentiate from a reqular SquareD circuit breaker and a

    Time
    > > Delay SquareD circuit breaker. There doesn't appear to be any

    indications
    > on
    > > the breaker itself.
    > >
    > > Thanks for any and all information.
    > >

    >
    > Always check the specks before buying. I am a mech. engineer, not an
    > electrician, but I think all breakers are time delay. Some are GFCI, or

    arc
    > fault, leading to other things to check for.You do not give much

    information
    > as to the event, but it sounds to me like a wiring, or compressor problem
    > not a breaker problem.
    > How far does the wire run from the main panel to the garage (voltage drops
    > under load at the outlet)?
    > Is this a plug in compressor or a hard wired one?
    > Did the motor start up then blow the breaker, or did the breaker trip
    > without the motor turning?
    > With the compressor disconnected from the power and the air lines open,
    > assuming it is accessible can you turn the motor by hand?
    > Did you remove all the shipping materials?
    >
    >


    - The circuit breaker popped as soon as I turned on the power switch of the
    compressor - the compressor itself didn't come on at all.

    - It's a plug in compressor, it's not hard wired. I plugged it into the
    outlet in my garage.

    - The specifications in the manual says that I need a time-delay fuse but a
    circuit breaker would be better.

    - "Perhaps circuit breakers are all time delay".

    Anyway, I reset the breaker and decideed to try it again - and it actually
    works now, HURRAAAAYYYYY!!! :)

    Perhaps the compressor popped the breaker the first time because it was new
    and had not been turned on before???


    Besides that, the 12/3 wire that I have running to the garage is about 40
    feet long. I think I'm gonna try to get 10/3 or bigger, and perhaps even
    I'll try to install a sub electric panel in the garage!

    Thanks for all.

    Guy Doucet
    Guy Doucet, May 15, 2005
    #4
  5. Guy Doucet

    Guy Doucet Guest

    Re: I need a time-delay Square D breaker for a new air compressor... thanks all

    <> wrote in message
    news:SKvhe.41398$gc6.40844@okepread04...
    > Guy Doucet <> wrote:
    > >I built a garage a few years ago and brought a 12/3 wire to it which I
    > >had connected to a 20 Amp SquareD circuit breaker I bought.

    >
    > About how long is the run from the breaker panel to the garage?
    >
    > >I have the following in my garage
    > >- garage door opener, 8 x 100Watt light bulbs, Table saw, Old Shop Vac,
    > >etc...

    >
    > If all 8 light bulbs are on then you probably will pop the breaker if
    > you try to run the compressor.
    >
    > >So then I read in the compressor manual where I found the following
    > >specifications:
    > >- Voltage-Single Phase 120V/60Hz/1Ph
    > >- Minimum Branch Circuit Requirement 15 amps
    > >- Fuse Type Time Delay (circuit breaker is preffered)

    >
    > >QUESTION
    > >How can I differentiate from a reqular SquareD circuit breaker and a Time
    > >Delay SquareD circuit breaker.

    >
    > The terseness of the label is a bit confusing. "Time delay" refers to
    > the fuse type, not the breaker type. A better way to put it would be:
    >
    > ---
    > If you use a fuse on the circuit for this compressor, use a time delay
    > type fuse. A regular fuse will blow when the motor starts.
    >
    > Using a circuit breaker, instead of a fuse, is preferred.
    > ---
    >
    > Nearly all circuit breakers that you're likely to encounter in your
    > house are already "time delay". They are made this way for precisely
    > your application: starting motors. Motors draw a lot more current when
    > they start up than they do when they are running, but if the motor is
    > working correctly, this high current draw only lasts for a few seconds.
    > If the high current draw persists for longer than that, the breaker will
    > trip.
    >
    > In a perfect world, the compressor would have a 15 amp breaker all to
    > itself. One thing to check is that all connections on the circuit,
    > starting at the breaker panel, are clean and tight. If you have a bad
    > connection, the resistance of the circuit will go up, which will lower
    > the voltage at the compressor motor. Within certain limits, the motor
    > will attempt to draw more current to compensate, which might trip the
    > breaker. If you have a voltmeter, you might be able to tell. Measure
    > the voltage at an outlet in the garage with everything or nearly
    > everything in the garage shut off, and note the reading. Then go around
    > and turn on all the lights and maybe the vacuum, then with all that
    > stuff running, take another reading at the same outlet. It will be
    > lower than the first reading by a volt or two, but if it's 10 or 20
    > volts lower, you have a problem - either a bad connection somewhere, or
    > the 12/3 wire was too small for the distance between your garage and the
    > breaker panel.
    >
    > If you used "push in" connections that did not require you to also
    > tighten a screw, redo each connection like this, this time putting the
    > wire under the screw head. Make sure all wire nuts are on tight, and
    > so on.
    >
    > Warning: Electricity can kill you, so be careful. Get help from an
    > electrician if needed.
    >
    > Matt Roberds
    >


    - The circuit breaker popped as soon as I turned on the power switch of the
    compressor - the compressor itself didn't come on at all.

    - It's a plug in compressor, it's not hard wired. I plugged it into the
    outlet in my garage.

    - The specifications in the manual says that I need a time-delay fuse but a
    circuit breaker would be better.

    - "Perhaps circuit breakers are all time delay".

    Anyway, I reset the breaker and decideed to try it again - and it actually
    works now, HURRAAAAYYYYY!!! :)

    Perhaps the compressor popped the breaker the first time because it was new
    and had not been turned on before???


    Besides that, the 12/3 wire that I have running to the garage is about 40
    feet long. I think I'm gonna try to get 10/3 or bigger, and perhaps even
    I'll try to install a sub electric panel in the garage!

    Thanks for all.

    Guy Doucet
    Guy Doucet, May 15, 2005
    #5
  6. In article <k5uhe.1351942$Xk.880065@pd7tw3no>,
    "Fred" <> writes:
    > Sounds like you should take a look at the motor amp rating and horsepower on
    > that new compressor of yours.
    >
    > A compressor motor will draw up to three times its rated running amperage to
    > start up. Could be up to 45 amps in your case depending on the motor
    > horsepower.
    >
    > Have never heard of a "time-delay" circuit breaker???


    They're standard in Europe. Breakers are rated Type B,
    Type C, or Type D. Type B will allow through 3-5 times
    the rating for a short time without tripping, type C is
    5-10 times, and type D is 10-50 times.

    Type B is the standard breaker used in the home. Type C
    is normally used for things like aircon and other large
    motors. Type D is specialist use and not found in the home.
    Square D manufacture this range for Europe (might not go up
    to Type D -- generally only industrial breaker ranges do).

    (In the UK, we used to have Type 1, 2, 3, and 4 with similar
    meanings, but have switched over to the common EU types now.)

    --
    Andrew Gabriel
    Andrew Gabriel, May 15, 2005
    #6
  7. Guy Doucet

    Brian Guest

    Update the wiring to your garage. Run a dedicated line for the compressor for starters. Or put a
    sub panel in the garage. Or call a qualified electrician before your house burns down.


    <> wrote in message news:...
    On Sat, 14 May 2005 18:17:36 GMT Guy Doucet <> wrote:

    | QUESTION
    | How can I differentiate from a reqular SquareD circuit breaker and a Time
    | Delay SquareD circuit breaker. There doesn't appear to be any indications on
    | the breaker itself.

    The standard breakers have a combination magnetic trip and thermal trip.
    The magnetic trip is generally set at a few times the breaker rating.
    That should trip in the case of a short circuit. The thermal trip would
    be close to accurate, and this is the time delay part.

    Apparently the starting current for your compressor is pulling quite a
    lot of current. How fast does your breaker trip? If immediate, then
    it is the magentic element doing the job. Increasing the breaker rating
    would not generally help because that element is usually around the same
    rating for breaker from 15 to 60 amps.

    If there is any delay from compressor start to breaker trip, it could be
    that the compressor is pulling locked rotor amps for too long of a period.
    Maybe it needs some appropriate maintainance, lubrication, etc.

    Breakers that can be adjusted for magnetic trip point and time delay do
    exist, but they are expensive (well over $1000).

    --
    -----------------------------------------------------------------------------
    | Phil Howard KA9WGN | http://linuxhomepage.com/ http://ham.org/ |
    | (first name) at ipal.net | http://phil.ipal.org/ http://ka9wgn.ham.org/ |
    -----------------------------------------------------------------------------
    Brian, May 17, 2005
    #7
  8. Guy Doucet

    Ben Miller Guest

    "Guy Doucet" <> wrote in message
    news:4hrhe.12959$...
    >
    > QUESTION
    > How can I differentiate from a reqular SquareD circuit breaker and a Time
    > Delay SquareD circuit breaker. There doesn't appear to be any indications
    > on
    > the breaker itself.
    >


    You need a QO-HM breaker ("high magnetic"). They are designed to withstand
    much higher inrush current than the standard QO, and they are physically
    interchangeable. Available in 15 or 20 amp rating. You probably won't find
    them at the local home center store, however.

    Ben Miller

    --
    Benjamin D. Miller, PE
    B. MILLER ENGINEERING
    www.bmillerengineering.com
    Ben Miller, May 20, 2005
    #8
  9. Guy Doucet

    Bob Guest

    Re: I need a time-delay Square D breaker for a new air compressor... thanks all

    On Sat, 14 May 2005 23:28:49 GMT, "Guy Doucet"
    <> wrote:

    >
    ><> wrote in message
    >news:SKvhe.41398$gc6.40844@okepread04...
    >> Guy Doucet <> wrote:
    >> >I built a garage a few years ago and brought a 12/3 wire to it which I
    >> >had connected to a 20 Amp SquareD circuit breaker I bought.

    >>
    >> About how long is the run from the breaker panel to the garage?
    >>
    >> >I have the following in my garage
    >> >- garage door opener, 8 x 100Watt light bulbs, Table saw, Old Shop Vac,
    >> >etc...

    >>
    >> If all 8 light bulbs are on then you probably will pop the breaker if
    >> you try to run the compressor.
    >>
    >> >So then I read in the compressor manual where I found the following
    >> >specifications:
    >> >- Voltage-Single Phase 120V/60Hz/1Ph
    >> >- Minimum Branch Circuit Requirement 15 amps
    >> >- Fuse Type Time Delay (circuit breaker is preffered)

    >>
    >> >QUESTION
    >> >How can I differentiate from a reqular SquareD circuit breaker and a Time
    >> >Delay SquareD circuit breaker.

    >>
    >> The terseness of the label is a bit confusing. "Time delay" refers to
    >> the fuse type, not the breaker type. A better way to put it would be:
    >>
    >> ---
    >> If you use a fuse on the circuit for this compressor, use a time delay
    >> type fuse. A regular fuse will blow when the motor starts.
    >>
    >> Using a circuit breaker, instead of a fuse, is preferred.
    >> ---
    >>
    >> Nearly all circuit breakers that you're likely to encounter in your
    >> house are already "time delay". They are made this way for precisely
    >> your application: starting motors. Motors draw a lot more current when
    >> they start up than they do when they are running, but if the motor is
    >> working correctly, this high current draw only lasts for a few seconds.
    >> If the high current draw persists for longer than that, the breaker will
    >> trip.
    >>
    >> In a perfect world, the compressor would have a 15 amp breaker all to
    >> itself. One thing to check is that all connections on the circuit,
    >> starting at the breaker panel, are clean and tight. If you have a bad
    >> connection, the resistance of the circuit will go up, which will lower
    >> the voltage at the compressor motor. Within certain limits, the motor
    >> will attempt to draw more current to compensate, which might trip the
    >> breaker. If you have a voltmeter, you might be able to tell. Measure
    >> the voltage at an outlet in the garage with everything or nearly
    >> everything in the garage shut off, and note the reading. Then go around
    >> and turn on all the lights and maybe the vacuum, then with all that
    >> stuff running, take another reading at the same outlet. It will be
    >> lower than the first reading by a volt or two, but if it's 10 or 20
    >> volts lower, you have a problem - either a bad connection somewhere, or
    >> the 12/3 wire was too small for the distance between your garage and the
    >> breaker panel.
    >>
    >> If you used "push in" connections that did not require you to also
    >> tighten a screw, redo each connection like this, this time putting the
    >> wire under the screw head. Make sure all wire nuts are on tight, and
    >> so on.
    >>
    >> Warning: Electricity can kill you, so be careful. Get help from an
    >> electrician if needed.
    >>
    >> Matt Roberds
    >>

    >
    >- The circuit breaker popped as soon as I turned on the power switch of the
    >compressor - the compressor itself didn't come on at all.
    >
    >- It's a plug in compressor, it's not hard wired. I plugged it into the
    >outlet in my garage.
    >
    >- The specifications in the manual says that I need a time-delay fuse but a
    >circuit breaker would be better.
    >
    >- "Perhaps circuit breakers are all time delay".
    >
    >Anyway, I reset the breaker and decideed to try it again - and it actually
    >works now, HURRAAAAYYYYY!!! :)
    >
    >Perhaps the compressor popped the breaker the first time because it was new
    >and had not been turned on before???
    >
    >
    >Besides that, the 12/3 wire that I have running to the garage is about 40
    >feet long. I think I'm gonna try to get 10/3 or bigger, and perhaps even
    >I'll try to install a sub electric panel in the garage!
    >
    >Thanks for all.
    >
    >Guy Doucet
    >
    >

    That was likely your problem. 40' of 12/3 cord might have just enough
    voltage drop to cause the breaker to trip IF the utility voltage
    happened to already be a bit low that moment. Probably the 2nd time
    you tried it, the utility line was back to normal and it worked
    without tripping the breaker. If I were you, I would do exactly as you
    indicated; buy a 10/3 cordset if you need to go that far.

    And that other post was correct. You were taken in by the poor wording
    of that label. "Time Delay" was refering to only the fuse, all circuit
    breakers are "time delay" by nature of their design.
    Bob, May 25, 2005
    #9
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