Odd Voltage motor

[delectric123]

I am wiring a 1 hp motor for a 36" ventilating fan. the motor brand is something like MFLEX?????? the voltage on its nameplate is 265/460. what in the world is 265 volts? and its not just a typo, the amperage on its nameplate is 4.0/2.3. did anybody ever hear of such a thing? since my system voltage is 120/240 3 PH. delta, i don't think i'll have problem with it. though, with 208 v i bet it would get a bit warm.

 

[Hv&Lv]

Here is another thread on the subject that will help.


http://forums.mikeholt.com/showthread.php?t=149182

 

[norcal]

I am wiring a 1 hp motor for a 36" ventilating fan. the motor brand is something like MFLEX?????? the voltage on its nameplate is 265/460. what in the world is 265 volts? and its not just a typo, the amperage on its nameplate is 4.0/2.3. did anybody ever hear of such a thing? since my system voltage is 120/240 3 PH. delta, i don't think i'll have problem with it. though, with 208 v i bet it would get a bit warm.

265V is 277V. A PTAC for a 277V supply would be rated at 265V for example.

 

[templdl]

I am wiring a 1 hp motor for a 36" ventilating fan. the motor brand is something like MFLEX?????? the voltage on its nameplate is 265/460. what in the world is 265 volts? and its not just a typo, the amperage on its nameplate is 4.0/2.3. did anybody ever hear of such a thing? since my system voltage is 120/240 3 PH. delta, i don't think i'll have problem with it. though, with 208 v i bet it would get a bit warm.

Including a picture of the name plate would go along way to provide an accurate answer to your question.
It should also state if it is a 1ph or 3ph motor and if it is connected in a D or Y.
You see 265v really is not that strange. A nominal 480y/277v 3ph 4w is 480/1.73=277, 277 being the line to neutral voltage.
And 460y/265 3ph4w is 460/1.73=266.
Writing a voltage as 265/460 is a bit weird at best. If you have a 1ph motor it may be capable of being connected as 265 (266)v L-N or 460v L-L.
However by not actually seeing the actual name plate this is ONLY an assumption and not to be considered as an accurate answer.

 

[kwired]

what in the world is 265 volts?

Well it is one more than 264 and one less than 266:happyyes:

I have to agree with others that it is a 1.73 factor of 460. Other than that more details are necessary to know exactly why it is marked as such. Does it have a high and low volt wiring diagram? I guess it could be made to connect windings in wye configuration for 460 volt and in delta configuration for 264 volts, but finding a 264 volt three phase source would be pretty rare I think.

 

[delectric123]

Including a picture of the name plate would go along way to provide an accurate answer to your question.It should also state if it is a 1ph or 3ph motor and if it is connected in a D or Y.You see 265v really is not that strange. A nominal 480y/277v 3ph 4w is 480/1.73=277, 277 being the line to neutral voltage.And 460y/265 3ph4w is 460/1.73=266.Writing a voltage as 265/460 is a bit weird at best. If you have a 1ph motor it may be capable of being connected as 265 (266)v L-N or 460v L-L.However by not actually seeing the actual name plate this is ONLY an assumption and not to be considered as an accurate answer.

the motor operates on 3 ph. and if they would have meant 277, then the nameplate would have said so. yes, it has a high and low volt wiring diagram sorry, unable to provide a pic of the nameplate for now. I started up the fans on 240v 3 ph. and their current draw is not abnormal, though i question how it would work with 208.

 

[templdl]

the motor operates on 3 ph. and if they would have meant 277, then the nameplate would have said so. yes, it has a high and low volt wiring diagram sorry, unable to provide a pic of the nameplate for now. I started up the fans on 240v 3 ph. and their current draw is not abnormal, though i question how it would work with 208.

Oh well. When I address questions my first concern is that I'm responding to someone who has a working knowledge of safe electrical practices an procedure. There are numerous red flags that I have noted in the OP and the subsequent response that raises many concerns.
I fail to see your reasoning that 265v is a 3ph voltage to begin with and that 240v 3ph is acceptable to you and are even questioning if 208v is doable. In addition how have you determined that the current being drawn at 240v is not abnormal. Please advise what you have judged to be "normal"?
This whole scenario is a bit strange.
Please be safe.

 

[iwire]

and if they would have meant 277, then the nameplate would have said so

No, not usually.

Just like motor for 480 is marked 460 and a motor rated for 240 is marked 230 and a motor for 208 will be marked 200.

 

[Hv&Lv]

IMO the motor is from another country and is something like this, http://www.pfeiffer-vacuum.com/productPdfs/PKD46035.en.pdf

 

[delectric123]

Oh well. When I address questions my first concern is that I'm responding to someone who has a working knowledge of safe electrical practices an procedure. There are numerous red flags that I have noted in the OP and the subsequent response that raises many concerns. I fail to see your reasoning that 265v is a 3ph voltage to begin with and that 240v 3ph is acceptable to you and are even questioning if 208v is doable. In addition how have you determined that the current being drawn at 240v is not abnormal. Please advise what you have judged to be "normal"? This whole scenario is a bit strange.Please be safe.

the system voltage(240 v.) and the motors were selected by the ventilation company. i am doing the wiring. the designer claimed that the 265 v is just a typo, but i disagree. the motor is 3 ph., so that means, believe it or not, 265 v 3 ph.

 

[templdl]

the system voltage(240 v.) and the motors were selected by the ventilation company. i am doing the wiring. the designer claimed that the 265 v is just a typo, but i disagree. the motor is 3 ph., so that means, believe it or not, 265 v 3 ph.

I guess one learns something new every day as in my 30 years in the industry here in the USA I have never ran across any where that 265v 3ph was available. That would mean that there is a transformer with a 265v 3ph secondary which could be a delta or a 265y/153. Interesting. I have run across mislabeled name plates from time to time. Have you given any thought to confirming the motor name plate with the motor manufacturer?

 

[delectric123]

i once showed the motor to one of the ventilating company employees, and he mumbled something about that its probably italian.

 

[gar]

130408-1544 EDT

Over the years the nominal voltage has changed. Something like 110, 115, 117, and now 120. Then there would be integer multiples of these. Back in DC days there may have been a 100 V nominal.

My guess on this motor is that it can be connected wye or delta. The coils are 460/1.732 = 266.

If the coils were connected in delta, then the motor would have a nominal rating to be supplied from a 266 line to line delta. But when the motor coils are wired in a wye fashion, then the nominal delta source would be 460 line to line. Here I am sort of meaning nominal to be the voltage at the motor and it would tolerate a +/- variation from this value. See iwire's table.

There are some motors on CNC machines with vector drives that have the motor wiring under program control change from wye to delta and vice versa to improve torque capability under varying operating conditions (different speeds) to optimize the drive equipment.

.

 

[templdl]

130408-1544 EDT

Over the years the nominal voltage has changed. Something like 110, 115, 117, and now 120. Then there would be integer multiples of these. Back in DC days there may have been a 100 V nominal.

My guess on this motor is that it can be connected wye or delta. The coils are 460/1.732 = 266.

If the coils were connected in delta, then the motor would have a nominal rating to be supplied from a 266 line to line delta. But when the motor coils are wired in a wye fashion, then the nominal delta source would be 460 line to line. Here I am sort of meaning nominal to be the voltage at the motor and it would tolerate a +/- variation from this value. See iwire's table.

There are some motors on CNC machines with vector drives that have the motor wiring under program control change from wye to delta and vice versa to improve torque capability under varying operating conditions (different speeds) to optimize the drive equipment.

.

It is somewhat intriguing that a 3ph 1hp motor that has been described is being used in such a simple application.

 

[Jraef]

As mentioned, this is just the way Europeans list dual voltage motors. For THEM, dual voltage is accomplished simply by connecting the motor windings in a Star (Wye) pattern for their higher voltage, i.e. 400V, or a Delta pattern for their lower voltage, i.e. 230V. They do it that way in all countries where they use both voltages and in countries where they don't, the people theoretically know enough not to use the wrong voltage.

But here in North America, and in particular the US, we don't do it that way. For us, a dual voltage motor is 460 or 230V, accomplished by putting the windings in series or in parallel, not Delta or Wye. This is a completely foreign to an EU company who is not making a "global" product. So if they make their motors available for sale in the US, they are adapting their nameplates to suit us. If you use a motor designed for 400V 50Hz, you can DIRECTLY use it at 460V 60Hz, the V/Hz ratio is well within tolerance; 400/50 = 8:1, 460/60 = 7.67:1, and the tolerance is +-10%. But because they are USED TO putting the dual voltage information on the nameplate, they go ahead and do it. That then means that for us, the motor voltage is connected in Delta is 460/1.732 = 255.6 or rounded to 266V. There is no such animal though, it's just a fluke of the nameplate values.

If you apply 230V to it, you are going to under-flux the motor by a percentage that is now far outside of the design tolerance. The motor will have significantly less torque, which means higher slip, it will pull more current and will over heat if fully loaded. You either need to use a buck-boost transformer to get your 230V up closer to 266V, or just go get an off-the-shelf transformer and run it with 460V.