- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
Given a 3-phase motor with a dual rating of 230/460V, if we change the power source from 240V to 480V, would this require the wiring to be reconfigured?
Dual-Rated Motor
- Thread starter charlie b
- Start date
- Status
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
If you mean inside of the motor, yes. Inside of the motor peckerhead (or on the nameplate) there will be a diagram showing how the motor connections need to be changed.
But if you meant the external wiring, then no, just what dkidd said.
- Location
- Lockport, IL
- Occupation
- Retired Electrical Engineer
I have a question from the field for a project that was issued before my time. The persons involved are no longer working at this office. The drawing says to rewire the motor for 480V. It is not clear to me what was meant by that.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
As stated above, that's done at the motor terminals, basically rewiring each phase's windings from parallel to series.
Different connections for a 4% change of voltage???
Frank DuVal
Senior Member
- Occupation
- Electrical Contractor, Electrical Engineer
240 to 480 is twice the voltage. So, 100% change going up.
Diagrams in Ugly's. Page 48 of the 2005 edition.
Diagrams in Ugly's. Page 48 of the 2005 edition.
Might I suggest you read the opening post again?240 to 480 is twice the voltage. So, 100% change going up.
Diagrams in Ugly's. Page 48 of the 2005 edition.
LarryFine
Master Electrician Electric Contractor Richmond VA
- Location
- Henrico County, VA
- Occupation
- Electrical Contractor
If the voltage was being halved instead, the existing conductor size could have been an issue.
Ainsley Whyte
Senior Member
- Location
- Jamaica
- Occupation
- Senior Electrical Engineer
The answer to this question is yes the motor is connected delta for one voltage and star for the other voltage
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Ainsley Whyte
Senior Member
- Location
- Jamaica
- Occupation
- Senior Electrical Engineer
as i said before for the 460 V the connection would be star connection when 230v v is connected Delta
Ainsley Whyte
Senior Member
- Location
- Jamaica
- Occupation
- Senior Electrical Engineer
connection is change in the motor terminal usually a matter of rearranging three links
Ainsley Whyte
Senior Member
- Location
- Jamaica
- Occupation
- Senior Electrical Engineer
“reconnect” would have been a better way to describe what needs to be done instead of “rewire”.
GeorgeB
ElectroHydraulics engineer (retired)
- Location
- Greenville SC
- Occupation
- Retired
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
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
- Location
- San Francisco Bay Area, CA, USA
- Occupation
- Electrical Engineer
No, not true for 230/460V motors, that applies to IEC motors that are 230/400V...
texie
Senior Member
- Location
- Fort Collins, Colorado
- Occupation
- Electrician, Contractor, Inspector
In some cases the starter may be to large to put in the required (now smaller) overload protection.
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