Dear sganesh,

What are the nameplates showing?

Are the motors connected properly?

Are there no fuses blown?

What happens when one motor is switched off?

Can you interchange the two motors and measure again?

Are the Amp-measurements executed in the same way? (f.i both measurements in one phase).

Etc.

A practical good field engineers employs field action.

Best regards

Teus ■

Dear sganesh,

The 2 motors are not the same.

One is for 380V-50Hz and the other is for 415V-50Hz. Their powerfactor is slightly different (0.6135 and 0.6086)

The given 1000 rpm is the synchronous rpm. The full load rpm can (and probably will) differ.

The north motor (380V) is fed with 415V and therefore will deliver a torque that is a factor (415/380)^2 = 19% higher.

Your information does not tell, whether the no load test were with one motor or with 2 motors at the same time.

As I understand, NOT being a vibrating screen expert, the 2 motors are mechanically coupled through the screen.

Therefore the 2 motors have to share the load, according to their torque curves and mechanical load, which are probably not the same.

As this is vibrating equipment, the vibration load on each motor can differ in phase.

Looking at the different no load Amps, I would say that the 2 motors are encountering different loads. A vibrating screen experienced person is needed.

All for now.

Teus ■

Dear sganesh,

The question now are:

1- Are the two motors getting the same load? (dissipation of vibrating energy the same for each motor?)

2- Do the 2 motors have the same Torque/rpm curve for sharing a load?.

The torque curves are NOT the same because the 2 motors are different.

The 380V motors can deliver a higher torque because it is running on 415V.

An experienced engineer is needed. (from this forum perhaps)

success

Teus ■

It is fairly important for the use of the same type motor mfr and motor specifications. Unmatched is NOT DESIRABLE.

Guage or length of wiring to motors may not be the same or the new unmatched motor may require a higher grade of wire? FOR electrical experts to say.

Feed end motors could draw higher amps due to HIGHER LOAD to handle at the FEED END vs discharge end motors which handle less load and hence would theoretically draw less amps, for less work.

Originally Posted by Teus Tuinenburg

Dear sganesh,

The question now are:

1- Are the two motors getting the same load? (dissipation of vibrating energy the same for each motor?)

2- Do the 2 motors have the same Torque/rpm curve for sharing a load?.

The torque curves are NOT the same because the 2 motors are different.

The 380V motors can deliver a higher torque because it is running on 415V.

An experienced engineer is needed. (from this forum perhaps)

success

Teus

■

Hi sganesh,

Coupled or not: This is a bad idea to run a motor with a different voltage from the data tag. Can you get a replacement motor with the correct rating? This is the most likely the reason for your Amperage being off. With a higher voltage the actual running speed is likely different from the other motor, this can put an additional load ont the motor especially if they are coupled to one another. ■

sganesh

Is the feeder working correctly? You should have two identical motors but if the feeder works and you can't change motors for any reason - where is the problem? ■