Maximum number of starts per hour

Discussion in 'Electrical Engineering' started by BIGEYE, Jun 16, 2005.

  1. BIGEYE

    BIGEYE Guest

    We have two submersible pumps (UK Spec) -
    Pump 1
    250 kW, 4 Pole (1480 RPM), 690 Volts

    Pump 2
    250 kW, 6 Pole (965 RPM), 690 Volts

    They are both controlled by inverters and typically the maximum speed is
    about 85% of nameplate speed.
    What is the maximum number of starts per hour for each pump.
    Appreciate if anyone can advise.
    TIA
    BIGEYE, Jun 16, 2005
    #1
    1. Advertising

  2. BIGEYE

    SQLit Guest

    "BIGEYE" <address@is[invalid].ok> wrote in message
    news:42b1d710$0$24474$...
    > We have two submersible pumps (UK Spec) -
    > Pump 1
    > 250 kW, 4 Pole (1480 RPM), 690 Volts
    >
    > Pump 2
    > 250 kW, 6 Pole (965 RPM), 690 Volts
    >
    > They are both controlled by inverters and typically the maximum speed is
    > about 85% of nameplate speed.
    > What is the maximum number of starts per hour for each pump.
    > Appreciate if anyone can advise.
    > TIA


    The manufacture would be the place to find out. Not knowing the service
    factor of the motors and the loading it is only a guess.

    We have motors (larger) that we allow 3 starts per hour. All motors over 250
    hp are limited to 6 starts an hour. Per manufactures specs.
    SQLit, Jun 16, 2005
    #2
    1. Advertising

  3. BIGEYE

    operator jay Guest

    "SQLit" <> wrote in message
    news:SLlse.75$9%...
    >
    > "BIGEYE" <address@is[invalid].ok> wrote in message
    > news:42b1d710$0$24474$...
    > > We have two submersible pumps (UK Spec) -
    > > Pump 1
    > > 250 kW, 4 Pole (1480 RPM), 690 Volts
    > >
    > > Pump 2
    > > 250 kW, 6 Pole (965 RPM), 690 Volts
    > >
    > > They are both controlled by inverters and typically the maximum speed is
    > > about 85% of nameplate speed.
    > > What is the maximum number of starts per hour for each pump.
    > > Appreciate if anyone can advise.
    > > TIA

    >
    > The manufacture would be the place to find out. Not knowing the service
    > factor of the motors and the loading it is only a guess.
    >
    > We have motors (larger) that we allow 3 starts per hour. All motors over

    250
    > hp are limited to 6 starts an hour. Per manufactures specs.
    >
    >


    You might also check your inverter specs. I have seen speed drive models
    where you use the normal duty version for 'typical' applications, and you
    use a heavy duty version for the severe starting applications.

    I have seen the same for solid state soft starters.

    This was for products in the AltiVar and AltiStart series, which you may
    very well have 'over there' because the catalog had voltage like 400V and
    690V listed as well. I don't know if my catalog was branded Square D or
    what but I think they would probably trade as Telemecanique there.

    j
    operator jay, Jun 17, 2005
    #3
  4. BIGEYE

    BIGEYE Guest

    "operator jay" <> wrote in message
    news:Gsrse.4619$...
    >
    > "SQLit" <> wrote in message
    > news:SLlse.75$9%...
    >>
    >> "BIGEYE" <address@is[invalid].ok> wrote in message
    >> news:42b1d710$0$24474$...
    >> > We have two submersible pumps (UK Spec) -
    >> > Pump 1
    >> > 250 kW, 4 Pole (1480 RPM), 690 Volts
    >> >
    >> > Pump 2
    >> > 250 kW, 6 Pole (965 RPM), 690 Volts
    >> >
    >> > They are both controlled by inverters and typically the maximum speed
    >> > is
    >> > about 85% of nameplate speed.
    >> > What is the maximum number of starts per hour for each pump.
    >> > Appreciate if anyone can advise.
    >> > TIA

    >>
    >> The manufacture would be the place to find out. Not knowing the service
    >> factor of the motors and the loading it is only a guess.
    >>
    >> We have motors (larger) that we allow 3 starts per hour. All motors over

    > 250
    >> hp are limited to 6 starts an hour. Per manufactures specs.
    >>
    >>

    >
    > You might also check your inverter specs. I have seen speed drive models
    > where you use the normal duty version for 'typical' applications, and you
    > use a heavy duty version for the severe starting applications.
    >
    > I have seen the same for solid state soft starters.
    >
    > This was for products in the AltiVar and AltiStart series, which you may
    > very well have 'over there' because the catalog had voltage like 400V and
    > 690V listed as well. I don't know if my catalog was branded Square D or
    > what but I think they would probably trade as Telemecanique there.
    >
    > j
    >
    >


    The inverters are ABB.
    BIGEYE, Jun 17, 2005
    #4
  5. BIGEYE

    operator jay Guest

    "BIGEYE" <address@is[invalid].ok> wrote in message
    news:42b25e36$0$22591$...
    > "operator jay" <> wrote in message
    > news:Gsrse.4619$...
    > >
    > > "SQLit" <> wrote in message
    > > news:SLlse.75$9%...
    > >>
    > >> "BIGEYE" <address@is[invalid].ok> wrote in message
    > >> news:42b1d710$0$24474$...
    > >> > We have two submersible pumps (UK Spec) -
    > >> > Pump 1
    > >> > 250 kW, 4 Pole (1480 RPM), 690 Volts
    > >> >
    > >> > Pump 2
    > >> > 250 kW, 6 Pole (965 RPM), 690 Volts
    > >> >
    > >> > They are both controlled by inverters and typically the maximum speed
    > >> > is
    > >> > about 85% of nameplate speed.
    > >> > What is the maximum number of starts per hour for each pump.
    > >> > Appreciate if anyone can advise.
    > >> > TIA
    > >>
    > >> The manufacture would be the place to find out. Not knowing the service
    > >> factor of the motors and the loading it is only a guess.
    > >>
    > >> We have motors (larger) that we allow 3 starts per hour. All motors

    over
    > > 250
    > >> hp are limited to 6 starts an hour. Per manufactures specs.
    > >>
    > >>

    > >
    > > You might also check your inverter specs. I have seen speed drive

    models
    > > where you use the normal duty version for 'typical' applications, and

    you
    > > use a heavy duty version for the severe starting applications.
    > >
    > > I have seen the same for solid state soft starters.
    > >
    > > This was for products in the AltiVar and AltiStart series, which you may
    > > very well have 'over there' because the catalog had voltage like 400V

    and
    > > 690V listed as well. I don't know if my catalog was branded Square D or
    > > what but I think they would probably trade as Telemecanique there.
    > >
    > > j
    > >
    > >

    >
    > The inverters are ABB.
    >
    >


    OK. All I'm saying is that, if you're looking into the maximum number of
    starts per hour for your motors, you might want to check the same 'rating',
    or intended application, of your inverters. Sorry I can't help on the
    actual question you posted, about the motors themselves.

    j
    operator jay, Jun 17, 2005
    #5
  6. BIGEYE

    daestrom Guest

    "SQLit" <> wrote in message
    news:SLlse.75$9%...
    >
    > "BIGEYE" <address@is[invalid].ok> wrote in message
    > news:42b1d710$0$24474$...
    >> We have two submersible pumps (UK Spec) -
    >> Pump 1
    >> 250 kW, 4 Pole (1480 RPM), 690 Volts
    >>
    >> Pump 2
    >> 250 kW, 6 Pole (965 RPM), 690 Volts
    >>
    >> They are both controlled by inverters and typically the maximum speed is
    >> about 85% of nameplate speed.
    >> What is the maximum number of starts per hour for each pump.
    >> Appreciate if anyone can advise.
    >> TIA

    >
    > The manufacture would be the place to find out. Not knowing the service
    > factor of the motors and the loading it is only a guess.
    >
    > We have motors (larger) that we allow 3 starts per hour. All motors over
    > 250
    > hp are limited to 6 starts an hour. Per manufactures specs.
    >


    I'd be surprised if they allowed even six. IIRC, most motors of that size
    are limited to only 2 starts in three hours, or one restart if it was
    already up to temperature. Some really large units are limited to one start
    in 3 hours (these are MW range though).

    Of course, it depends too on the type of 'start'. A 'soft start' of an
    unloaded motor from a static inverter system might be very 'gentle' to the
    unit and be allowed any number of times. Also, if they had forced cooling
    (separate fans or circulating water). Or unusual insulation class...

    As always, the manufacturer would be the best place to start. But also look
    into the inverter design. 'Soft start' or VFD may be a lot more tolerable.
    (especially centrifugal pumps that have very low torque requirements at low
    speeds).

    daestrom
    daestrom, Jun 17, 2005
    #6
  7. BIGEYE

    Bob Guest

    it's all wrong. Inverters can start motors at 100% LA, so there is On
    Fri, 17 Jun 2005 17:12:44 GMT, "daestrom"
    <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:

    >
    >"SQLit" <> wrote in message
    >news:SLlse.75$9%...
    >>
    >> "BIGEYE" <address@is[invalid].ok> wrote in message
    >> news:42b1d710$0$24474$...
    >>> We have two submersible pumps (UK Spec) -
    >>> Pump 1
    >>> 250 kW, 4 Pole (1480 RPM), 690 Volts
    >>>
    >>> Pump 2
    >>> 250 kW, 6 Pole (965 RPM), 690 Volts
    >>>
    >>> They are both controlled by inverters and typically the maximum speed is
    >>> about 85% of nameplate speed.
    >>> What is the maximum number of starts per hour for each pump.
    >>> Appreciate if anyone can advise.
    >>> TIA

    >>
    >> The manufacture would be the place to find out. Not knowing the service
    >> factor of the motors and the loading it is only a guess.
    >>
    >> We have motors (larger) that we allow 3 starts per hour. All motors over
    >> 250
    >> hp are limited to 6 starts an hour. Per manufactures specs.
    >>

    >
    >I'd be surprised if they allowed even six. IIRC, most motors of that size
    >are limited to only 2 starts in three hours, or one restart if it was
    >already up to temperature. Some really large units are limited to one start
    >in 3 hours (these are MW range though).
    >
    >Of course, it depends too on the type of 'start'. A 'soft start' of an
    >unloaded motor from a static inverter system might be very 'gentle' to the
    >unit and be allowed any number of times. Also, if they had forced cooling
    >(separate fans or circulating water). Or unusual insulation class...
    >
    >As always, the manufacturer would be the best place to start. But also look
    >into the inverter design. 'Soft start' or VFD may be a lot more tolerable.
    >(especially centrifugal pumps that have very low torque requirements at low
    >speeds).
    >
    >daestrom
    >
    Bob, Jul 19, 2005
    #7
  8. BIGEYE

    Bob Guest

    Wrong wrong wrong all.

    A VFD can start the motor at 100% FLA. Starting restrictions are based
    upon Across-the-Line (DOL) starting, where the starting current will
    be 600% FLA. Using a VFD means there are NO RESTRICTIONS to the number
    of starts per hour, other than those imposed by ramp settings. That is
    true for both the drive and the motor.

    Soft starters are another thing all together. The Starts-per-hour
    rating of the motor stays exactly the same. Some soft starters, and
    ESPECIALLY that Telemecanique piece of junk mentioned earlier, are so
    cheaply built that they can take FEWER starts per hour than the motor
    they are connected to. There are many brands that are built to exceed
    the starts ratings of their motors, but that is not one of them. You
    need to ask that question when selecting a soft starter, but many
    people don't bother.


    On Fri, 17 Jun 2005 17:12:44 GMT, "daestrom"
    <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:

    >
    >"SQLit" <> wrote in message
    >news:SLlse.75$9%...
    >>
    >> "BIGEYE" <address@is[invalid].ok> wrote in message
    >> news:42b1d710$0$24474$...
    >>> We have two submersible pumps (UK Spec) -
    >>> Pump 1
    >>> 250 kW, 4 Pole (1480 RPM), 690 Volts
    >>>
    >>> Pump 2
    >>> 250 kW, 6 Pole (965 RPM), 690 Volts
    >>>
    >>> They are both controlled by inverters and typically the maximum speed is
    >>> about 85% of nameplate speed.
    >>> What is the maximum number of starts per hour for each pump.
    >>> Appreciate if anyone can advise.
    >>> TIA

    >>
    >> The manufacture would be the place to find out. Not knowing the service
    >> factor of the motors and the loading it is only a guess.
    >>
    >> We have motors (larger) that we allow 3 starts per hour. All motors over
    >> 250
    >> hp are limited to 6 starts an hour. Per manufactures specs.
    >>

    >
    >I'd be surprised if they allowed even six. IIRC, most motors of that size
    >are limited to only 2 starts in three hours, or one restart if it was
    >already up to temperature. Some really large units are limited to one start
    >in 3 hours (these are MW range though).
    >
    >Of course, it depends too on the type of 'start'. A 'soft start' of an
    >unloaded motor from a static inverter system might be very 'gentle' to the
    >unit and be allowed any number of times. Also, if they had forced cooling
    >(separate fans or circulating water). Or unusual insulation class...
    >
    >As always, the manufacturer would be the best place to start. But also look
    >into the inverter design. 'Soft start' or VFD may be a lot more tolerable.
    >(especially centrifugal pumps that have very low torque requirements at low
    >speeds).
    >
    >daestrom
    >
    Bob, Jul 19, 2005
    #8
    1. Advertising

Want to reply to this thread or ask your own question?

It takes just 2 minutes to sign up (and it's free!). Just click the sign up button to choose a username and then you can ask your own questions on the forum.
Similar Threads
  1. ldbk

    Appliance Output per Hour

    ldbk, Dec 20, 2006, in forum: Electronic Basics
    Replies:
    12
    Views:
    465
    Gareth
    Dec 21, 2006
  2. rqo

    Per Hour Charge

    rqo, Sep 22, 2006, in forum: Security Alarms
    Replies:
    23
    Views:
    514
    Crash Gordon
    Sep 29, 2006
  3. aussiblu
    Replies:
    3
    Views:
    1,122
    Luke O'Zade
    Jan 17, 2009
  4. Glenn Ashmore

    20 hour vs. 50 hour battery rating

    Glenn Ashmore, Dec 25, 2006, in forum: Boat Electronics
    Replies:
    4
    Views:
    343
    Glenn Ashmore
    Dec 25, 2006
  5. Bart Z. Lederman

    Life vs. number of starts for CFL UV lamp.

    Bart Z. Lederman, Jul 28, 2006, in forum: Lighting
    Replies:
    4
    Views:
    295
Loading...

Share This Page