Motor nameplate data question...

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VinceS

Senior Member
I have a Leroy Somer motor on which the nameplate is as confusing as the spec sheet;

Totally enclosed three-phase powersaving
asynchronous motors, LSES series,
according to IEC 60034, 60038, 60072; power
1.1 to 90 kW, frame size 80 to 280 mm.

Single speed: 2 and 4 poles; 230/400 V or
400 V Δ, 50 Hz.
The selection tables for motors in this
catalogue allow for:
• Direct on line starting on the mains supplies
230 V or 400 V operating in:
- delta connection (Δ) at 230 V,
- star connection (Υ) at 400 V.

• Star/delta start (Υ/Δ) on mains supply 400 V
with:
- star connection (Υ) during initial starting,
- delta connection (Δ) on 400 V duty.

********************************************************
How would the above listed motor data be wired at the motor junction box when connected to a drive with a 480VAC source? Delta or Wye

The nameplate and spec sheet seem to indicate the motor should be in a Wye configuration at high voltage. But it is in conflict with the later star/delta info.

The motor is currently in a OEM provided delta configuration and the drive rarely runs above 50% base speed or 30 Hz so the voltage never at max from the drive.


********************************************************
 

ohmhead

Senior Member
Location
ORLANDO FLA
Well delta full voltage attached to a drive .

If you had a old starter wye /delta then you would have two taps for connection and contactors do the changing from the wye to delta but on a freq drive its the delta connection it changes the inrush current for you so a delta connection is all you need.

Wire it up for full running motor delta .
 
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mcclary's electrical

Senior Member
Location
VA
The drive must be configured for this voltage and then you terminate in the peckerhead for delta. If you were starting it with contactors it would start on WYE and run on DELTA
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
Something is wrong with the nameplate information...I don't see how that information can be on one motor. In the direct line starting info the motor windings would be rated at 230 volts. In the wye start/delta run, the windings would have to be rated at 400 volts. Is this a 6 lead or 12 lead motor?
 

topgone

Senior Member
Something is wrong with the nameplate information...I don't see how that information can be on one motor. In the direct line starting info the motor windings would be rated at 230 volts. In the wye start/delta run, the windings would have to be rated at 400 volts. Is this a 6 lead or 12 lead motor?

The winding voltage rating is 230V. If you operate that motor on 230V 3-phase supply, you're okay! But if you want it to run it on 480V 3-phase, you need a 480/400 V transformer. Your motor cannot run on 480V as it is.
 

VinceS

Senior Member
More info...

More info...

The motor has a 6 terminal junction box with shorting bars to configure it as wye or delta.
 

don_resqcapt19

Moderator
Staff member
Location
Illinois
Occupation
retired electrician
The motor has a 6 terminal junction box with shorting bars to configure it as wye or delta.
Then it is not possilble to have both of the configerations shown on the sheet on that motor. It is either a dual voltage 230/400 volt motor or it is a 400 volt for wye start/ delta run. I can't be both with out letting the magic smoke out.
 

Jraef

Moderator, OTD
Staff member
Location
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Occupation
Electrical Engineer
There are a couple of things going on here.
1) This is a 230/400V 50Hz motor. Motors can operate just fine if you maintain a constant V/Hz ratio. So the 400V winding connection is based on a V/Hz ration of 8:1 (400/50). If you apply 60Hz to it, the same ratio would give you 60*8 = ...ta daaaa 480V! So no problem using this motor at 480V 60Hz, except maybe in that it will spin 20% faster than what the nameplate says and you will get 20% more HP out of it as a result. That may affect thinks like couplings and other power transmission components.

2) The Y-Delta starting issue is completely separate. If you want to start it with a Y-Delta motor starter AND use the higher voltage, you need to have a single voltage motor designed for that. So you would order a motor as 230V Y-Delta start, OR 400V Y Delta start. Your information appears to be catalog data referring to an entire series of motors, not something direct from the actual nameplate of a specific one. What that indicates to me is that you CAN order it as a dual-voltage motor with the Y used for high voltage and Delta connections for low, OR you can order it as a single voltage Y-Delta start. But to have both, it would need to be a 12 lead motor.

Take a look at this chart. For your IEC motor, scroll to about 3/4 down towards the bottom of the page and look for the section titled "IEC Nomenclature--6 & 12 Leads:" You can see that for motors with 6 leads there is a connection pattern for SINGLE voltage with Y-Delta starting, or DUAL voltage connections, but no Y-Delta starting. So you can have one OR the other in a 6 lead motor, but if you want dual voltage and Y-Delta starting, it needs 12 leads.
 
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There are a couple of things going on here.
1) This is a 230/400V 50Hz motor. Motors can operate just fine if you maintain a constant V/Hz ratio. So the 400V winding connection is based on a V/Hz ration of 8:1 (400/50). If you apply 60Hz to it, the same ratio would give you 60*8 = ...ta daaaa 480V! So no problem using this motor at 480V 60Hz, except maybe in that it will spin 20% faster than what the nameplate says and you will get 20% more HP out of it as a result. That may affect thinks like couplings and other power transmission components.

2) The Y-Delta starting issue is completely separate. If you want to start it with a Y-Delta motor starter AND use the higher voltage, you need to have a single voltage motor designed for that. So you would order a motor as 230V Y-Delta start, OR 400V Y Delta start. Your information appears to be catalog data referring to an entire series of motors, not something direct from the actual nameplate of a specific one. What that indicates to me is that you CAN order it as a dual-voltage motor with the Y used for high voltage and Delta connections for low, OR you can order it as a single voltage Y-Delta start. But to have both, it would need to be a 12 lead motor.

Take a look at this chart. For your IEC motor, scroll to about 3/4 down towards the bottom of the page and look for the section titled "IEC Nomenclature--6 & 12 Leads:" You can see that for motors with 6 leads there is a connection pattern for SINGLE voltage with Y-Delta starting, or DUAL voltage connections, but no Y-Delta starting. So you can have one OR the other in a 6 lead motor, but if you want dual voltage and Y-Delta starting, it needs 12 leads.

Theoretically a motor can be built for dual voltage, eg the same winding can be used at different voltages, resulting in different kW shaft power. A set of three windings can be connected to a star/delta starter with all 6 leads bought to the starter.

6 leads can only be a 2 OR 4 pole motor if one set of the 3 wires would represent an internally delta or star winding on 2 poles and the other set of three are internally wired for 4 poles. "Star-delta" wiring in that case would represent a two speed, two winding wiring.
 

VinceS

Senior Member
More Info...

More Info...

Yes the info was cut from the spec sheet, and for the purpose of the question was identical.

The name plate's, there were 2, included:

LSMV180LU-T
HP 35.4
RPM 1768
Delta 277 FLA 70.2A
Wye 480 FLA 40.4A
PF .84
EFF 93.4 @ 60Hz
SF 1
and everything for the EU 50Hz on the other

I have contacted the MFR's Tech Support, in St Louis, He specified the motor would be normally be wired Wye when using 480VAC in and out of the drive.

My associate contacted tech support, New Jersey, for Emerson, current owner of Leroy Somer. He was told that the motor is wired Wye by design, to maintain torque iaw some EU Engineering norm... Has anyone run across this before?

As stated in the first post, the motor is connected to a drive, everyone seems to have gotten side tracked by the star delta starting. I might not have been as specific as necessary, and should have specified my confusion of the voltages listed for delta, 277V or wye, 480V. Most of the American and EU motors I have wired are Wye 277V and Delta 480V.
 
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Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
Yes the info was cut from the spec sheet, and for the purpose of the question was identical.

The name plate's, there were 2, included:

LSMV180LU-T
HP 35.4
RPM 1768
Delta 277 FLA 70.2A
Wye 480 FLA 40.4A
PF .84
EFF 93.4 @ 60Hz
SF 1
and everything for the EU 50Hz on the other

I have contacted the MFR's Tech Support, in St Louis, He specified the motor would be normally be wired Wye when using 480VAC in and out of the drive.

My associate contacted tech support, New Jersey, for Emerson, current owner of Leroy Somer. He was told that the motor is wired Wye by design, to maintain torque iaw some EU Engineering norm... Has anyone run across this before?

As stated in the first post, the motor is connected to a drive, everyone seems to have gotten side tracked by the star delta starting. I might not have been as specific as necessary, and should have specified my confusion of the voltages listed for delta, 277V or wye, 480V. Most of the American and EU motors I have wired are Wye 277V and Delta 480V.

There are no standard North American motors designed for 277Y / 480V Delta, you are confusing motor connections with transformer connections. They are apples and oranges.

Your motor is an IEC design, it is intended to be connected to the higher voltage in Y, the lower voltage in Delta. NEMA (North American) motors are not designed this way, they are made with separate windings when they are dual voltage and you connect the windings in series for the higher voltage, parallel for the lower. The dual voltage motors used here are for 240/480V. You cannot compare the designs to one another, the philosophy is completely different.

Forget all the Y-Delta starting stuff as well, it is completely irrelevant if you are connecting to a VFD. Connect the motor internally in Y if you are using a 480V drive.
 

VinceS

Senior Member
Correction

Correction

He was told that the motor is wired Wye by design, to maintain torque iaw some EU Engineering norm... Has anyone run across this before?

Should read:

He was told that the motor is wired Delta by design, to maintain torque iaw some EU Engineering norm... Has anyone run across this before?

oops....
 

Jraef

Moderator, OTD
Staff member
Location
San Francisco Bay Area, CA, USA
Occupation
Electrical Engineer
He was told that the motor is wired Wye by design, to maintain torque iaw some EU Engineering norm... Has anyone run across this before?

Should read:

He was told that the motor is wired Delta by design, to maintain torque iaw some EU Engineering norm... Has anyone run across this before?

oops....
Ah, that makes more sense (got your PM on this BTW).

Yes, this is an old VFD trick. Motor torque is dependent upon a V/Hz ratio being maintained. So for a 480V 60Hz motor, that ratio is 8:1 (480/60). If you want to run a motor above base speed, the problem you have is that once you get to full voltage, you cannot keep increasing the voltage above the line supply (a VFD cannot create magic voltage) to maintain the proper V/Hz ratio and you lose torque as you increase speed. For example at 100Hz and the same 480V, your V/Hz ratio dropped to 4.8:1. So the trick is, you wire a dual-voltage motor for the LOWER voltage, but feed the higher voltage into the VFD. Then you program the VFD to reach that lower voltage at the motor's base speed, which allows you to continue increasing the Hz beyond that because now you can keep increasing the voltage with it. It's easier to understand with an example, I'll use yours:

The motor is strapped for Delta, in this case 277V. That makes the motor's native V/Hz ratio become 277/60 or 4.6:1. You program the VFD to deliver 277V at 60Hz, so everything within the motor is copacetic; you get full torque at 60Hz. But because you actually have 480V available to the VFD input, you can now allow the VFD output frequency to increase by 1.732 times normal, to 104Hz, without losing torque because at 104Hz and 480V, the ratio is 480/104 = 4.61!

If you didn't do this and wired the motor for 480V, once you reached 60Hz you would be at 480V and you are done. If you wanted to increase speed to 100Hz, the torque would be dropping starting at 61Hz (although not by much at first) and by the time you got to 100Hz you would have almost 1/2 of the normal motor torque, risking a stall.
 

VinceS

Senior Member
If you can't find a white paper just ask Jraef!

If you can't find a white paper just ask Jraef!

Thanks all, and some again, much more than others...
 

LarryFine

Master Electrician Electric Contractor Richmond VA
Location
Henrico County, VA
Occupation
Electrical Contractor
The dual voltage motors used here are for 240/480V.
Sidebar, if I may. (This isn't worth it's own new thread.)

If the motor is rated 208/240/480 (208/230/460, actually), wouldn't it run just fine on 416v when wired for 480?
 
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