European motor nameplate values 1

[TestBeforeTouch]

A 750KW, 4000V European motor at my plantsite in the US lists three parameters that I am not familiar with and I have not been able to find a reference on:
Ma/Mn = .7
Ia/In = 5.3
Te = 16s

The Ia/In looks like the ratio of locked rotor current to full load current (maybe Iaccel./Inormal) but I am not sure. Any help would be appreciated.

 

[stardelta]

Those markings are typical of those found on Exe (increased safety) motors built to EN IEC 60079-9

Ia/In, Is the ratio of stalled current to normal current, it must not exceed 10

Te, Is the time taken in secs under a stall condition for the winding temp to rise from its intended max running temp to the max temp allowable for the class of insulation used in the motors construction......The overload device MUST disconnect the motor within this time.

I am not familiar with the Ma/Mn marking, maybe Scotty is?

 

[edison123]

Ma/Mn= Starting Torque/Running Torque

 

[Marke]

Ma/Mn is the Locked Rotor Torque.
Ia/In is the Locked Rotor Current.
Te is the motor start time constant and is used to define the protection class required.

Best regards,

Mark Empson

http://www.lmphotonics.com

 

[TestBeforeTouch]

Thank all of you for the prompt responses. I am modernizing the motor protection relay and this information will be helpful in my settings.