600 VAC Toshiba 2 speed motor won't start

[gerrybhoy]

I have a newly installed 575VAC toshiba motor that won't turn under uncoupled bump testing . The motor is 40/13.7 HP 2 speed 3330/1250 rpm so there is a low and high speed . we ended up changing out the motor thinking it was a bad motor but again same thing . the inrush current doesn't come down on low speed either . the motor just vibrates noisily. it sounds and looks very much like single phasing but we have equal albeit high current on all 3 amprobes

any help greatly appreciated

 

[macmckim]

Gerrybhoy
You are showing a 575V power motor (making it a 60HZ unit) - but your noted speeds of 3330 / 1250 RPM does not work for a 60HZ motor. What voltage & frequency are you applying?

 

[xnuke]

Have all shipping clamps been removed?

xnuke
"Live and act within the limit of your knowledge and keep expanding it to the limit of your life." Ayn Rand, Atlas Shrugged.
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[gerrybhoy]

macmckim (Electrical)20 Nov 22 21:36
Gerrybhoy
You are showing a 575V power motor (making it a 60HZ unit) - but your noted speeds of 3330 / 1250 RPM does not work for a 60HZ motor. What voltage & frequency are you applying?

575 vac leaving mcc cell and yes 60 hz all 3 phases showing current but motor still seems like its single phasing uncoupled

 

[gerrybhoy]

xnuke (Electrical)20 Nov 22 21:48
Have all shipping clamps been removed?

yes and it spins freely by hand

 

[gerrybhoy]

macmckim (Electrical)20 Nov 22 21:36
Gerrybhoy
You are showing a 575V power motor (making it a 60HZ unit) - but your noted speeds of 3330 / 1250 RPM does not work for a 60HZ motor. What voltage & frequency are you applying?

Also to note it is a direct replacement but i believe noe a high efficiency motor

 

[che12345]

Dear Mr. gerrybhoy (Electrical)
1. Please take a photo of the motor name-plate with all the data , especially on the connection for hi and lo speeds. It should be on the motor name-plate, otherwise inside the terminal cover. Refer the motor installation/ connection for hi and lo speed.
2. Show a simple free-hand drawing how had you wired up the two-speed connection, showing the terminals and windings.
3. Take a photo of the two-speed starter schematic diagram showing the contactor formation for hi and lo speed, including the terminal connected to and the formation of the winding.
4. FYI : there are numerous 2-speed motors/starters on the market. Based on your data [3200/1250 rpm, 40/13.7 hp], it may? be is a 2/4 pole motor with YY/Y Dahlander connection. The type of starter MUST be selected for the type that is designed for the winding.
Che Kuan Yau (Singapore)

 

[edison123]

Is it a single winding two speeds or two windings two speeds?

With the power applied, try turning the shaft to see if it rotates. If it does rotate, your starter connections are wrong since both the motors are not starting.

It could be cogging, but I doubt Toshiba made that basic design mistake.

Muthu

http://www.edison.co.in

 

[zlatkodo]

There are so many missing details here.
It's not possible to make any suggestions at all.
Read what Mr. Che wrote.

Motor Repair and Winding Design

 

[LionelHutz]

Is this a full-voltage contactor starter or something else?

Does it rotate slowly with notching or stepping in the rotation?