Maximum number of starts per hour

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" <address@is[invalid].ok> wrote in message
news:42b1d710$0$24474$(E-Mail Removed)...
> 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" <(E-Mail Removed)> wrote in message
news:SLlse.75$9%(E-Mail Removed)...
>
> "BIGEYE" <address@is[invalid].ok> wrote in message
> news:42b1d710$0$24474$(E-Mail Removed)...
> > 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" <(E-Mail Removed)> wrote in message
news:Gsrse.4619$(E-Mail Removed)...
>
> "SQLit" <(E-Mail Removed)> wrote in message
> news:SLlse.75$9%(E-Mail Removed)...
>>
>> "BIGEYE" <address@is[invalid].ok> wrote in message
>> news:42b1d710$0$24474$(E-Mail Removed)...
>> > 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" <address@is[invalid].ok> wrote in message
news:42b25e36$0$22591$(E-Mail Removed)...
> "operator jay" <(E-Mail Removed)> wrote in message
> news:Gsrse.4619$(E-Mail Removed)...
> >
> > "SQLit" <(E-Mail Removed)> wrote in message
> > news:SLlse.75$9%(E-Mail Removed)...
> >>
> >> "BIGEYE" <address@is[invalid].ok> wrote in message
> >> news:42b1d710$0$24474$(E-Mail Removed)...
> >> > 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

"SQLit" <(E-Mail Removed)> wrote in message
news:SLlse.75$9%(E-Mail Removed)...
>
> "BIGEYE" <address@is[invalid].ok> wrote in message
> news:42b1d710$0$24474$(E-Mail Removed)...
>> 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

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" <(E-Mail Removed)> wrote in message
>news:SLlse.75$9%(E-Mail Removed)...
>>
>> "BIGEYE" <address@is[invalid].ok> wrote in message
>> news:42b1d710$0$24474$(E-Mail Removed)...
>>> 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
>

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" <(E-Mail Removed)> wrote in message
>news:SLlse.75$9%(E-Mail Removed)...
>>
>> "BIGEYE" <address@is[invalid].ok> wrote in message
>> news:42b1d710$0$24474$(E-Mail Removed)...
>>> 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
>