Tek-Tips is the largest IT community on the Internet today!
Members share and learn making Tek-Tips Forums the best source of peer-reviewed technical information on the Internet!
-
Congratulations cowski on being selected by the Eng-Tips community for having the most helpful posts in the forums last week. Way to Go!
175hp motor ?
- Thread starter sunloco
- Start date
This website and forum is not for this sort of thing. Your message and my reply may both be red-tagged for it!
150 and 200 HP are the only sizes you will find in a standard 3ph induction mtr.
Do web searches for motor mfr's websites, and vendors websites. Here in the USA a vendor with lots of online info is Grainger.
150 and 200 HP are the only sizes you will find in a standard 3ph induction mtr.
Do web searches for motor mfr's websites, and vendors websites. Here in the USA a vendor with lots of online info is Grainger.
I don't see the problem with his question. Just because one can't find it on a website does not mean it doesn't exist. Remember, although most posters are in N. America, this is a worldwide forum.
Of course in this case, it turns out that it doesn't exist, but I don't think the question deserves a red flag. A simple no should suffice.
Eng-Tips: Help for your job, not for your homework Read faq731-376![[pirate]](/data/assets/smilies/pirate.gif "[pirate] [pirate]")
Of course in this case, it turns out that it doesn't exist, but I don't think the question deserves a red flag. A simple no should suffice.
Eng-Tips: Help for your job, not for your homework Read faq731-376
![[infinity]](/data/assets/smilies/infinity.gif "[infinity] [infinity]")
sunloco, I did check the Brook Crompton catalogue (primarily an IEC manfacturer over here in Europe), they make the 175hp IEC motor as you state but not a NEMA version of the same power. Come to think of it, you can't easily convert between NEMA and IEC because "Eurovoltage" is 400V at 50Hz, and they are mechanically different, but apart from that..!
It has got to be 150 or 200hp.
It has got to be 150 or 200hp.
- Thread starter
- #7
Thanks for all above reply.
I am from China, Asia. Why I have this question is we now sell the USA aurora pump in China, China use 380V/3ph/50HZ ,normally IEC standard .
In IEC 132Kw is standard range for motor,but for Aurora pump ,motor is NEMA standard, It hasn't this range ,only big 200hp. Generally convert 200hp to Kilowatt is 150Kw,that means the motor doesn't have rivalrousness.so I have this question .
I am from China, Asia. Why I have this question is we now sell the USA aurora pump in China, China use 380V/3ph/50HZ ,normally IEC standard .
In IEC 132Kw is standard range for motor,but for Aurora pump ,motor is NEMA standard, It hasn't this range ,only big 200hp. Generally convert 200hp to Kilowatt is 150Kw,that means the motor doesn't have rivalrousness.so I have this question .
Sunloco,
The issue you are describing is a long standing one here in the US because we have been receiving IEC designed pump motors from a variety of sources for years. Generally when someone uses a motor of an odd size, we just accept that it is a kW rated motor even though we see ratings of, for example, 88HP or 175HP on the nameplate. In your case you have the opposite problem because you are apparently receiving a NEMA designed motor into an IEC applicaion that could have used a slightly smaller motor. What you may want to do is tell Aurora to supply you with an IEC designed motor. It may very well be possible, but they may need to get it from a different source than usual. Is there a reason why the oversizing to 150kW is a problem though?
Eng-Tips: Help for your job, not for your homework Read faq731-376
The issue you are describing is a long standing one here in the US because we have been receiving IEC designed pump motors from a variety of sources for years. Generally when someone uses a motor of an odd size, we just accept that it is a kW rated motor even though we see ratings of, for example, 88HP or 175HP on the nameplate. In your case you have the opposite problem because you are apparently receiving a NEMA designed motor into an IEC applicaion that could have used a slightly smaller motor. What you may want to do is tell Aurora to supply you with an IEC designed motor. It may very well be possible, but they may need to get it from a different source than usual. Is there a reason why the oversizing to 150kW is a problem though?
Eng-Tips: Help for your job, not for your homework Read faq731-376
Jraef,
I am in accordance with your above answer, and I don´t see too any problem with the sunloco´s question, I think we are in this forum because we want to help and be helped.No particular interest.
Taking account the sunloco´s question I think the NEMA motors can´t be so far from the IEC outputs the NEMA manufacturers play with 460 Volts motors that are going to be energized with 380 Volts. This Is a design problem and it is controlled by the NEMA manufacturers.They know what to do and how to label the name plate.
Regards
Petronila.
I am in accordance with your above answer, and I don´t see too any problem with the sunloco´s question, I think we are in this forum because we want to help and be helped.No particular interest.
Taking account the sunloco´s question I think the NEMA motors can´t be so far from the IEC outputs the NEMA manufacturers play with 460 Volts motors that are going to be energized with 380 Volts. This Is a design problem and it is controlled by the NEMA manufacturers.They know what to do and how to label the name plate.
Regards
Petronila.
Sunloco.
If the motor you have is 200 HP when operated at 60 HZ, it does not will be able to deliver the same power (200 HP) when supplied by 50HZ 380 Volts. The torque will be almost the same as in 60 HZ, whoever lowering the speed will drop the Power to around 200X50/60 = 167 HP. Then the motor has shorter HP not larger as originally you assumed. If the motor was matched to the pump for 60 HZ operation, you are lucky and it will work without any problem at 50 HZ since the drop of speed will reduce drastically the pump demanded power.
If the motor you have is 200 HP when operated at 60 HZ, it does not will be able to deliver the same power (200 HP) when supplied by 50HZ 380 Volts. The torque will be almost the same as in 60 HZ, whoever lowering the speed will drop the Power to around 200X50/60 = 167 HP. Then the motor has shorter HP not larger as originally you assumed. If the motor was matched to the pump for 60 HZ operation, you are lucky and it will work without any problem at 50 HZ since the drop of speed will reduce drastically the pump demanded power.
I might be a bit late posting, but we deal with this situation all of the time when shipping machines over seas...
You are correct, most (if not all) US manufacturers make a 150HP and 200HP motor, but nothing in between.
At 60HZ the pump will produce it's rated volume with 150HP. When you put the same motor on 50Hz, the motor HP is de-rated. This is OK, because the pump is now pumping 5/6 less volume. If you want the same volume at 50Hz, you need to put on a bigger pump to compensate and thus a bigger motor. The next up size happens to be 200HP.
You are correct, most (if not all) US manufacturers make a 150HP and 200HP motor, but nothing in between.
At 60HZ the pump will produce it's rated volume with 150HP. When you put the same motor on 50Hz, the motor HP is de-rated. This is OK, because the pump is now pumping 5/6 less volume. If you want the same volume at 50Hz, you need to put on a bigger pump to compensate and thus a bigger motor. The next up size happens to be 200HP.
- Moderator
- #12
I assume we are talking about a centrifugal pump.
The maximum pump pressure will also drop with the lower speed.
As the back pressure increases, the flow decreases, and the load on the motor decreases.
You really have to consult the manufacturers performance curves to determine the horsepower required at any combination of flow and dynamic head pressure.
There will be a different curve for every speed;
1200 RPM, 1500 RPM, 1800 RPM, 3000 RPM, 3600 RPM.
When you have calculated the motor size needed and then re-rated it from 50HZ to 60 HZ. If you need a 175 HP motor at 60HZ, the answer is "Sorry, not in the USA."
However, if you need a 132 KW motor, the 200 HP 60 HZ. motor will be a little bit too small after it is re-rated for 50HZ, (167 HP) but given the variable factors involved in pump motor sizing, it will probably work well in all installations except those that demand the maximum performance of the pump. Restricting the flow slightly will raise the dynamic head and reduce the power required.
The maximum pump pressure will also drop with the lower speed.
As the back pressure increases, the flow decreases, and the load on the motor decreases.
You really have to consult the manufacturers performance curves to determine the horsepower required at any combination of flow and dynamic head pressure.
There will be a different curve for every speed;
1200 RPM, 1500 RPM, 1800 RPM, 3000 RPM, 3600 RPM.
When you have calculated the motor size needed and then re-rated it from 50HZ to 60 HZ. If you need a 175 HP motor at 60HZ, the answer is "Sorry, not in the USA."
However, if you need a 132 KW motor, the 200 HP 60 HZ. motor will be a little bit too small after it is re-rated for 50HZ, (167 HP) but given the variable factors involved in pump motor sizing, it will probably work well in all installations except those that demand the maximum performance of the pump. Restricting the flow slightly will raise the dynamic head and reduce the power required.
- Status
Similar threads
- Question
- Question