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400Hz 3-phase power
Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. |
400Hz 3-phase power
On Tue, 05 Jul 2011 13:39:05 -0400, Spehro Pefhany
wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. my hitachi and my mitsubeshe (sp) both do 0 to 360 Hz. Karl |
400Hz 3-phase power
On 07/05/2011 11:45 AM, Spehro Pefhany wrote:
On Tue, 05 Jul 2011 10:52:22 -0700, Jim wrote: Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. It seems like a 60Hz to 400Hz converter would be a common accessory in avionics shops -- or do they go for avionics prices? -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html |
400Hz 3-phase power
Jim Stewart wrote:
Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? ha |
400Hz 3-phase power
Tim Wescott writes:
It seems like a 60Hz to 400Hz converter would be a common accessory in avionics shops -- or do they go for avionics prices? I suspect most provide a few watts; at best tens of same. -- A host is a host from coast to & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433 |
400Hz 3-phase power
"Tim Wescott" wrote in message ... On 07/05/2011 11:45 AM, Spehro Pefhany wrote: On Tue, 05 Jul 2011 10:52:22 -0700, Jim wrote: Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. It seems like a 60Hz to 400Hz converter would be a common accessory in avionics shops -- or do they go for avionics prices? 60 / 400 Hz motor gensets are a fairly common military surplus item these days |
400Hz 3-phase power
On 07/05/2011 01:45 PM, Spehro Pefhany wrote:
On Tue, 05 Jul 2011 10:52:22 -0700, Jim wrote: Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. A VFD does NOT produce 240 V sine waves. It produces 400 V square waves that are the equivalent to a MOTOR, ONLY! it will definitely fry any electronics you connect to it! It is theoretically possible to filter the VFD output, but that would be a significant job to build. Jon |
400Hz 3-phase power
On Tue, 05 Jul 2011 16:55:30 -0500, Jon Elson
wrote: On 07/05/2011 01:45 PM, Spehro Pefhany wrote: On Tue, 05 Jul 2011 10:52:22 -0700, Jim wrote: Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. A VFD does NOT produce 240 V sine waves. It produces 400 V square waves that are the equivalent to a MOTOR, ONLY! it will definitely fry any electronics you connect to it! I want to run an MG set off of it to get (a lot of) DC . ;-) It is theoretically possible to filter the VFD output, but that would be a significant job to build. Jon |
400Hz 3-phase power
On 07/05/2011 04:59 PM, Spehro Pefhany wrote:
On Tue, 05 Jul 2011 16:55:30 -0500, Jon wrote: A VFD does NOT produce 240 V sine waves. It produces 400 V square waves that are the equivalent to a MOTOR, ONLY! it will definitely fry any electronics you connect to it! I want to run an MG set off of it to get (a lot of) DC . ;-) It is theoretically possible to filter the VFD output, but that would be a significant job to build. Gee, seems like a VERY round-about way to make DC. But, if you already have the MG set, then it will work. Jon |
400Hz 3-phase power
On 07/05/2011 02:59 PM, Spehro Pefhany wrote:
On Tue, 05 Jul 2011 16:55:30 -0500, Jon wrote: On 07/05/2011 01:45 PM, Spehro Pefhany wrote: On Tue, 05 Jul 2011 10:52:22 -0700, Jim wrote: Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. A VFD does NOT produce 240 V sine waves. It produces 400 V square waves that are the equivalent to a MOTOR, ONLY! it will definitely fry any electronics you connect to it! I want to run an MG set off of it to get (a lot of) DC . ;-) It is theoretically possible to filter the VFD output, but that would be a significant job to build. Jon Then why not just get a big DC power supply? -- Tim Wescott Wescott Design Services http://www.wescottdesign.com Do you need to implement control loops in software? "Applied Control Theory for Embedded Systems" was written for you. See details at http://www.wescottdesign.com/actfes/actfes.html |
400Hz 3-phase power
On Tue, 05 Jul 2011 12:18:23 -0700, Tim Wescott
wrote: Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. It seems like a 60Hz to 400Hz converter would be a common accessory in avionics shops -- or do they go for avionics prices? Why do they use 400 Hz for anything? RWL |
400Hz 3-phase power
GeoLane at PTD dot NET GeoLane at PTD dot NET writes:
Why do they use 400 Hz for anything? 400 Hz reduces the iron needed in magnetics such as generators, motors and transformers. Weight is a big big factor in aircraft. -- A host is a host from coast to & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433 |
400Hz 3-phase power
On Wed, 6 Jul 2011 03:00:05 +0000 (UTC), David Lesher
wrote: GeoLane at PTD dot NET GeoLane at PTD dot NET writes: Why do they use 400 Hz for anything? 400 Hz reduces the iron needed in magnetics such as generators, motors and transformers. Weight is a big big factor in aircraft. Also makes it easier to get the speed required for gyro instruments. |
400Hz 3-phase power
Tim Wescott wrote: On 07/05/2011 02:59 PM, Spehro Pefhany wrote: On Tue, 05 Jul 2011 16:55:30 -0500, Jon wrote: On 07/05/2011 01:45 PM, Spehro Pefhany wrote: On Tue, 05 Jul 2011 10:52:22 -0700, Jim wrote: Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. A VFD does NOT produce 240 V sine waves. It produces 400 V square waves that are the equivalent to a MOTOR, ONLY! it will definitely fry any electronics you connect to it! I want to run an MG set off of it to get (a lot of) DC . ;-) It is theoretically possible to filter the VFD output, but that would be a significant job to build. Jon Then why not just get a big DC power supply? Did anyone consider that he wants to test that power supply? -- It's easy to think outside the box, when you have a cutting torch. |
400Hz 3-phase power
On 2011-07-05, Spehro Pefhany wrote:
Will any commonly available 240V VFDs go up to 400Hz? Some of the Mitsubishi ones will. Possibly others. You need to go into the configuration options to enable going that high. Need around 7.5HP. O.K. No knowledge about that. I have a 3 HP one which will go up to 400 Hz if properly configured. Good Luck, DoN. -- Remove oil spill source from e-mail Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
400Hz 3-phase power
On Jul 5, 12:45*pm, Spehro Pefhany
wrote: On Tue, 05 Jul 2011 10:52:22 -0700, Jim Stewart wrote: Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. I work in the avionics industry. Just how are you going to show all the environmental compliance test requirements. The commercial world uses RTCA DO-160() as the bible. There are many test requirements that must be shown for airworthiness. The big ones are that it does not upset other equipments, and is not a fire hazard. Even if the equipment is non-essential to safe flight and landing, it can not upset equipments that are essential or critical to SFL. Radiated and conducted RF emissions are the expensive test lab tests. Even for experimental test flights, the safety of flight paperwork must show that the equipment will not cause safety problems. ignator |
400Hz 3-phase power
On Jul 5, 12:45*pm, Spehro Pefhany
wrote: On Tue, 05 Jul 2011 10:52:22 -0700, Jim Stewart wrote: Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Powering up your surplus Minuteman missile? Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. I work in the avionics industry. Just how are you going to show all the environmental compliance test requirements. The commercial world uses RTCA DO-160() as the bible. There are many test requirements that must be shown for airworthiness. The big ones are that it does not upset other equipments, and is not a fire hazard. Even if the equipment is non-essential to safe flight and landing, it can not upset equipments that are essential or critical to SFL. Radiated and conducted RF emissions are the expensive test lab tests. Even for experimental test flights, the safety of flight paperwork must show that the equipment will not cause safety problems. ignator |
400Hz 3-phase power
On Wed, 6 Jul 2011 03:00:05 +0000 (UTC), David Lesher
wrote: GeoLane at PTD dot NET GeoLane at PTD dot NET writes: Why do they use 400 Hz for anything? 400 Hz reduces the iron needed in magnetics such as generators, motors and transformers. Weight is a big big factor in aircraft. Excellent. I learned my "something new every day" early today. Thanks. I'd wondered why they used that frequency in airplanes. -- Fear not those who argue but those who dodge. -- Marie Ebner von Eschenbach |
400Hz 3-phase power
On Wed, 06 Jul 2011 06:37:33 -0700, Larry Jaques
wrote: On Wed, 6 Jul 2011 03:00:05 +0000 (UTC), David Lesher wrote: GeoLane at PTD dot NET GeoLane at PTD dot NET writes: Why do they use 400 Hz for anything? 400 Hz reduces the iron needed in magnetics such as generators, motors and transformers. Weight is a big big factor in aircraft. Excellent. I learned my "something new every day" early today. Thanks. I'd wondered why they used that frequency in airplanes. Probably good for the old-fashioned mechanical gyros too.. which had to have motors that ran at high RPM. Of course modern strap-down nav systems tend to use fiber-optic or ring laser gyros. I wonder why 400Hz though, rather than 360 or something that's an integer multiple of 60Hz.. perhaps it originated in the UK where it would be an integer multiple of their 50Hz? I see an online claim that WWII-era German aircraft used 500Hz. Here's the MIL spec for aircraft power from '59: http://www.everyspec.com/MIL-STD/MIL...D_704.1080.pdf |
400Hz 3-phase power
Larry Jaques wrote:
On Wed, 6 Jul 2011 03:00:05 +0000 (UTC), David Lesher wrote: GeoLane at PTD dot NET GeoLane at PTD dot NET writes: Why do they use 400 Hz for anything? 400 Hz reduces the iron needed in magnetics such as generators, motors and transformers. Weight is a big big factor in aircraft. Excellent. I learned my "something new every day" early today. Thanks. I'd wondered why they used that frequency in airplanes. Yeah, no kidding. It also allows smaller, but higher speed induction motors. You won't believe how small a 1 Hp 22,000 RPM 400 Hz motor is, you can just about hold it between two fingers, and easily in the palm of your hand. Power transformers are also way smaller, if you haven't seen the difference, you won't believe it. Jon |
400Hz 3-phase power
On 7/6/2011 10:32 AM, Spehro Pefhany wrote:
Here's the MIL spec for aircraft power from '59: http://www.everyspec.com/MIL-STD/MIL...D_704.1080.pdf Here's the current spec, 704F. http://docimages.assistdocs.com/watermarker/transient/B0731B2B03B641D89CBFA7FB8886890F.pdf Kevin Gallimore |
400Hz 3-phase power
Larry Jaques wrote:
On Wed, 6 Jul 2011 03:00:05 +0000 (UTC), David Lesher GeoLane at PTD dot NET GeoLane at PTD dot NET writes: Why do they use 400 Hz for anything? 400 Hz reduces the iron needed in magnetics such as generators, motors and transformers. Weight is a big big factor in aircraft. Excellent. I learned my "something new every day" early today. Thanks. I'd wondered why they used that frequency in airplanes. Fear not those who argue but those who dodge. Usually, the newbies' next question concerns that box of dirt in the tail section for all the equipments' earth ground leads. ;-) Cheers! Rich |
400Hz 3-phase power
Spehro Pefhany wrote:
I wonder why 400Hz though, rather than 360 or something that's an integer multiple of 60Hz.. perhaps ... Nobody knows, but at least 2,150,000 people think they have an answer: http://www.google.com/search?hl=en&q...t+power+400+hz Cheers! Rich |
400Hz 3-phase power
Spehro Pefhany wrote:
Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. Three MONGO PA amps (think stadium or rock concert) and a 3-phase oscillator? ;-) Cheers! Rich |
400Hz 3-phase power
Jon Elson writes:
A VFD does NOT produce 240 V sine waves. It produces 400 V square waves that are the equivalent to a MOTOR, ONLY! it will definitely fry any electronics you connect to it! "Line Reactors" for 3-phase are surprisingly available and affordable. That said. I can't see why making 400hz to run a generator to provide DC is sensible. What voltage DC at what current? -- A host is a host from coast to & no one will talk to a host that's close........[v].(301) 56-LINUX Unless the host (that isn't close).........................pob 1433 is busy, hung or dead....................................20915-1433 |
400Hz 3-phase power
On Wed, 06 Jul 2011 17:01:09 -0400, the renowned axolotl
wrote: On 7/6/2011 10:32 AM, Spehro Pefhany wrote: Here's the MIL spec for aircraft power from '59: http://www.everyspec.com/MIL-STD/MIL...D_704.1080.pdf Here's the current spec, 704F. http://docimages.assistdocs.com/watermarker/transient/B0731B2B03B641D89CBFA7FB8886890F.pdf Kevin Gallimore Thanks. Best regards, Spehro Pefhany -- "it's the network..." "The Journey is the reward" Info for manufacturers: http://www.trexon.com Embedded software/hardware/analog Info for designers: http://www.speff.com |
400Hz 3-phase power
On 2011-07-06, GeoLane at PTD dot NET GeoLane wrote:
On Tue, 05 Jul 2011 12:18:23 -0700, Tim Wescott wrote: Close. Testing a mass of sophisticated equipment that gets crammed into a small cargo aircraft. It seems like a 60Hz to 400Hz converter would be a common accessory in avionics shops -- or do they go for avionics prices? Why do they use 400 Hz for anything? Transformers and AC electric motors (plus things like synchros, servos and resolvers) are a lot smaller and lighter (much less iron needed at that higher frequency) -- real benefits in aircraft. Included in the motors are the gryo motors as part of a navigation system, and the syncros or resolvers to transmit the information to the panel instruments. Enjoy, DoN. -- Remove oil spill source from e-mail Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
400Hz 3-phase power
On 2011-07-06, axolotl wrote:
On 7/6/2011 10:32 AM, Spehro Pefhany wrote: Here's the MIL spec for aircraft power from '59: http://www.everyspec.com/MIL-STD/MIL...D_704.1080.pdf Here's the current spec, 704F. http://docimages.assistdocs.com/watermarker/transient/B0731B2B03B641D89CBFA7FB8886890F.pdf Hmm ... I've just thought of something. I have a couple of ancient aircraft instruments (a gyrocompass and an artificial horizon) which each use a gyro powered by 115V 400 Hz three phase. Fine, those should work well with a VFD powering them. But also included are devices to adjust for proper axis on the gyros -- during spin up and more slowly once in the air. These consist of torque motors on each axis in the gymbals, which are fed current to bring that axis into alignment (vertical on the artificial horizon, and horizontal on the gyrocompass). Each of these are fed through a clip-in device which has what I suspect to be saline solution in the bottom of a shallow dome (curved down in the center), and feed that to four contacts at 90 degree intervals. I'm not sure how well that will balance with the synthesized sine waves output from the VFD. And -- FWIW -- I can use only one of these instruments at a time, because the stator (these are inverted rotor motors) in one is burned out, and it takes me about a half an hour or so to swap it from one to the other. :-) Hmm ... perhaps time to try rewinding the stator? I didn't even think of it back in the early 1960s when I first got these. :-) Enjoy, DoN. -- Remove oil spill source from e-mail Email: | Voice (all times): (703) 938-4564 (too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html --- Black Holes are where God is dividing by zero --- |
400Hz 3-phase power
Spehro Pefhany writes:
On Wed, 06 Jul 2011 17:01:09 -0400, the renowned axolotl wrote: On 7/6/2011 10:32 AM, Spehro Pefhany wrote: Here's the MIL spec for aircraft power from '59: http://www.everyspec.com/MIL-STD/MIL...D_704.1080.pdf Here's the current spec, 704F. http://docimages.assistdocs.com/watermarker/transient/B0731B2B03B641D89CBFA7FB8886890F.pdf Note the 787 is a bit different. http://www.groundsupportworldwide.com/online/printer.jsp?id=4620 |
400Hz 3-phase power
On Thu, 7 Jul 2011 02:36:15 +0000 (UTC), David Lesher
wrote: Spehro Pefhany writes: On Wed, 06 Jul 2011 17:01:09 -0400, the renowned axolotl wrote: On 7/6/2011 10:32 AM, Spehro Pefhany wrote: Here's the MIL spec for aircraft power from '59: http://www.everyspec.com/MIL-STD/MIL...D_704.1080.pdf Here's the current spec, 704F. http://docimages.assistdocs.com/watermarker/transient/B0731B2B03B641D89CBFA7FB8886890F.pdf Note the 787 is a bit different. http://www.groundsupportworldwide.com/online/printer.jsp?id=4620 Electric start. Perhaps not surprisingly, the A380 requires double the GPU capacity of a 747. www.naa.jp/en/annual/2007_pdf/09.pdf |
400Hz 3-phase power
On Wed, 06 Jul 2011 15:06:08 -0700, Rich Grise
wrote: Spehro Pefhany wrote: I wonder why 400Hz though, rather than 360 or something that's an integer multiple of 60Hz.. perhaps ... Nobody knows, but at least 2,150,000 people think they have an answer: http://www.google.com/search?hl=en&q...t+power+400+hz Cheers! Rich You can get MUCH better results if you learn to use advanced search options and better keywords (such as 'history'). Also, if you search books as well as the web-- but I don't see anything remotely authoritative yet. |
400Hz 3-phase power
On Tue, 05 Jul 2011 14:13:29 -0400, Ned Simmons wrote:
On Tue, 05 Jul 2011 13:39:05 -0400, Spehro Pefhany wrote: Will any commonly available 240V VFDs go up to 400Hz? Need around 7.5HP. At least some Yaskawas and Mitsubishis do; I've used them up in that range on high speed spindles. If you're ebaying for used Yaskawas, be aware that in the past many were rebranded as Magnetek GPD5xx. Actually..the other way around Magnatek was bought by Yaskawa in 2001 Gunner -- Maxim 12: A soft answer turneth away wrath. Once wrath is looking the other way, shoot it in the head. |
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