6RA70 Drive Field And Armature Current is not showing Equal

Current is as below

Field Current

F1 – 1.65 A , F2 – 1 A

Armature Current :

A1 – 0.3A,   A2 – 0.8 A

Please Suggest what parameter needs to change or checking is need to do.

DC motor terminal

F1 and F2 Field winding terminal and A1 and A2 Armature winding terminal.+ve and -ve sequentially.

In case of field, please check if any resistance is connected in series with field winding. It may be inside motor terminal or inside motor.

In case of armature, please check the connections of brush holder, brush rocker position of if rockers are fitted on single ring, please check if ring is fitted correctly. (Basically your brush must be exactly at 180 degree (i.e. +ve 180 & -ve 180 deg)

HTH

Sir

It is new motor and shunt wound type.

Name plater is attached herewith

Hello,

What type of DC motor it is? i.e. is it solid or laminated yoke? DC motor efficiency value in attached snap is not clear, but seems to be very low (+70 % <79 % at rated load) & motor seems to be normal DC motor (i.e. not feed or servo or multiquadrant) The readings which you noted in your query are seems to be at no load. So at no load losses are comparatively more & you may get reading difference. If possible, please take readings at load & compare.

BTW, Do you have OEM motor test certificate? 

Please check, if not ask for it to manufacturer/supplier & attach here. 

Even I suggest you to contact motor manufacturer for this problem. 

HTH.