Dual-Rated Motor

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Jraef

Jraef

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Staff member
Location
San Francisco Bay Area, CA, USA
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Unless it is a 12 lead motor set up for Part Winding or Wye-Delta starting, it will be a NEMA 9 lead motor connected using one of the diagrams below. The thing is, you will not know if it is a Delta or a Wye wound motor until you see the diagram that came with the motor. If it is small, it's likely Wye wound, but how small is small is something the motor mfr determines when designing it; it's really about economics. General rule of thumb though, at 480V 10HP and under will be Wye wound, 50HP and higher will be Delta wound, anything in between is a craps shoot.

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Eddie702

Licensed Electrician
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Western Massachusetts
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Electrician
Reconnect wiring at motor terminals. Install the proper sized overloads. This may require a change in the motor starter. Check the size of the branch circuit protection.
 
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Ainsley Whyte

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Jamaica
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GeorgeB said:
Ainsley, your 3 links suggestion is, I think, for a wye to delta change. A 230/460 motor will either have 9 or 12 leads (most 9, 12 if configurable for wye-delta at either voltage).

For 230, a pair of windings are connected in parallel. for 460, that pair are connected in series. Look at page 10 of an example 10 HP motor I randomly selected, https://www.baldorvip.com/Product/InfoPacketExternal/?id=CEM3774T
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you are so correct i look like i rush the post but never read properly my friend
 
kwired

kwired

Electron manager
Location
NE Nebraska
Ainsley Whyte said:
View attachment 2551766
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Those diagrams only identified as single voltage. If it is the same windings involved the Delta configuration each winding is connected to full line ot line input volts, same winding connected in wye sees 58% of line to line input volts because of the phase angles, that is why 230/400 is typical. If you want 230/460 ability you pretty much need a 9 or 12 lead motor.
 
kwired

kwired

Electron manager
Location
NE Nebraska
bwat said:
Can you post a picture of the nameplate of a 6 lead motor like this for 230/460? Some quick googling didn't yield good results for me. They looked like they were all 1.73 factors...
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Like I said if you want 230/460 you need 9 or 12 lead motors.

The vectors just don't come out to do it with 6 leads - the factor is 1.73 or .58 depending on which way you look at it.

With 230/460 and 9 or 12 lead motors you use delta or wye in both high and low voltage instead of switching between delta and wye for high/low volts. This means for low volts you put coils in parallel and high volts you put them in series but still in wye for both voltages or delta for both voltages.
 
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