Motor winding configuration
- Thread starter panthripu
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Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
You got me. And while it is probably just a bad plate, it looks like it is telling you that at 230 the motor draws 0.27 amps.
I'll fancy a guess....First of all, the "-Z" at the end of the Siemens catalog number indicates some special construction. #4 is simply the numbers at 460/60 when the motor is loaded at nameplate power (7.5 KW), #3 is max load at 460/60. Connecting 460 in wye would only be suitable for starting using a wye-delta starter, probably not practical for continuous use. There is no 60 hz wye rating because the correct voltage would likely exceed the insulation design voltage.
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I believe that is the rating of the brake, not the motor itself.
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Strathead
Senior Member
- Location
- Ocala, Florida, USA
- Occupation
- Electrician/Estimator/Project Manager/Superintendent
:slaphead:
It is more lightly loaded on option 4 and the slip is less.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
I agree, but because putting the term "Service Factor" on an IEC motor would cause confusion for IEC customers, they show it like this, knowing that IEC customers will ignore the 460/60 ratings anyway.
So in NEMA world, this is a 10HP motor with a 1.15 SF.
If connected in Star and applied with 480V your torque would drop to 1/3 of rated, so in essence you could use it as a 3HP motor with higher than normal slip and poorer power factor. Why would you want to do that unless as a Star-Delta starting scheme? I have no clue.
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kwired
Electron manager
- Location
- NE Nebraska
Kind of on track with the last couple posts here, it is rated at 7.5kW for 50 Hz.
@ 60 Hz you get one set of current, power factor, speed, etc. data, but it apparently is also rated 8.6 kW with another set of current, power factor, speed, etc. This may simply be the NEMA motor equivalent to a service factor?
Add: or maybe gives the motor the same rating as a NEMA motor rated in HP instead of KW?
@ 60 Hz you get one set of current, power factor, speed, etc. data, but it apparently is also rated 8.6 kW with another set of current, power factor, speed, etc. This may simply be the NEMA motor equivalent to a service factor?
Add: or maybe gives the motor the same rating as a NEMA motor rated in HP instead of KW?
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
Yes. 746W per HP
7.5kW / .746 = aprox. 10HP
10HP x 1.15SF = 11.5HP
11.5HP x .746 = aprox. 8.6kW
I hadn't thought about a 1.15 SF before Ing noted it.
But it made me wonder why the rating isn't expressed in HP at least for the 60Hz ratings.
Also interesting that for both 50Hz and 60Hz, the continuous rating is given as 7.5kW.
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
* Because it's Siemens.... When I worked there, we had an internal quip about "why" questions (said with an exaggerated German accent).
"Zere is der right vay, und der wrong vay, und der Ziemens vay.
Der right und der wrong ist unimportant, you VILL do it zees vay und you vill like it!"
Phil Corso
Senior Member
- Location
- Boca Raton, Fl, USA
So you too, have been influenced by "Herr Doctor"... the man in a white lab-coat, w/ glasses, a clip-board, and 6 colored pens in a pocket-protector! ! !
Phil
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