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IEC labeling of dual voltage motors with 9 and 12 leads

IEC labeling of dual voltage motors with 9 and 12 leads

IEC labeling of dual voltage motors with 9 and 12 leads

(OP)
This is about the IEC labeling and wiring of dual voltage motors with 9 and 12 leads.
Where to find valid IEC regulation?
There are various ways in practice.
See this WEG nameplate. Is it already outdated or there is something other?



9 leads, NEMA - IEC:


12 leads- IEC:

RE: IEC labeling of dual voltage motors with 9 and 12 leads

This is a standard dual voltage motor nameplate, IEC or otherwise. What is your question?

Muthu
www.edison.co.in

RE: IEC labeling of dual voltage motors with 9 and 12 leads

(OP)
Leads: U3; V3; W3 and U4; V4; W4 instead of U5; V5; W5 and U6; V6; W6.

RE: IEC labeling of dual voltage motors with 9 and 12 leads

This is a confusing post given the photograph of the nine lead motor has nothing to do
with the diagram showing connections for motors with 12 leads.

Perhaps the question could be rephrased?

John

RE: IEC labeling of dual voltage motors with 9 and 12 leads

Also, the WEG nameplate, for a connect and run it one way motor, probably has nothing to do with the separate diagram for a wye start-delta run motor. Apples, Oranges, and Apricots?

RE: IEC labeling of dual voltage motors with 9 and 12 leads

The correct diagram for connecting any motor is first and foremost the one that the motor manufacturer attached to the motor. The "standard" diagram shown below the photo is a convention, not a standard.


" We are all here on earth to help others; what on earth the others are here for I don't know." -- W. H. Auden

RE: IEC labeling of dual voltage motors with 9 and 12 leads

take another close look at the photo.
Nine terminals but 12 leads.

Parallel Delta:- 220 Volts.
Parallel Star:- 380 Volts.
Series Delta:- 440 Volts.
Series Star:- Starting only, no voltage given, but suitable for continuous running at 760 Volts.

Normal IEC motors are 6 lead, Star Delta, for two voltages in the ratio of 1.73/1.
Normal NEMA motors are 9 lead Series Parallel, for two voltages in the ratio of 2/1.
12 lead motors are not common but may be connected in Series Parallel, or Star Delta for 4 voltages.
Ratios of 1/1.73/2/3.46
Or 220 Volts, 380 Volts, 440 Volts, 760 Volts.
The WEG picture uses the convention:- U1, U2, U3, U4.
The second diagram uses the convention:, U1, U2, U5, U6.
If you look closely at the photo you will see that the top terminals each have 2 leads connected for a total of 12 leads.
Forget 9 leads.
Bill
--------------------
"Why not the best?"
Jimmy Carter

RE: IEC labeling of dual voltage motors with 9 and 12 leads

Quote:

If you look closely at the photo you will see that the top terminals each have 2 leads connected for a total of 12 leads.

Good catch, Bill.

The motor terminals as shown can be connected as high voltage wye or low voltage wye/wye.

Muthu
www.edison.co.in

RE: IEC labeling of dual voltage motors with 9 and 12 leads

(OP)
Waross, thanks for your explanation.
In addition:
As far as I know, the convention: U1, U2, U3, U4 should be for tapped windings with 12 leads, only, as is shown below:

But, the winding of weg motor ( see nameplate photo above) is not tapped winding for sure.
Split winding intended for series-parallel arrangement with 12 leads should be labeled as below:

This interrupting sequence U1, U2, U5, U6 is just chosen to distinguish this winding from the tapped winding.

RE: IEC labeling of dual voltage motors with 9 and 12 leads

Interesting how we beg for pictures around here. We get some... and still miss the obvious.

Agree on Bill's attention to detail. Did not notice the additional leads tucked underneath.

In looking at the photo with a little more "eye"... it appears the motor was connected
for a delta configuration when noting the 6 loose connection nuts from when the motor was disconnected.

Where to find valid IEC "regulation"?

The International Electrotechnical Commission (IEC) prepares and publishes International Standards. They are not referred to as regulations.

A few URLs for reference:

www.iec.ch/searchpub

webstore.iec.ch/justpublished

www.electropedia.org (electronic and electrical terms)

std.iec.ch/glossary

The additional diagram posted of the tapped windings does not apply to the
motors depicted (9 or 12 lead) in the discussion... which will further confuse the reader looking in on this conversation.

Attached screen shot(s) denote IEC connections for an externally connected 12 lead motor.

Additionally, my memory of WEG having different connections to their motors is a vague one. It was usually with their 12 lead motors, but I'll let someone else chase that one.

John

RE: IEC labeling of dual voltage motors with 9 and 12 leads

Below the three loose nuts on the right is a shorting jumper. Star connection.

Bill
--------------------
"Why not the best?"
Jimmy Carter

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