SIMOTICS

DC motor lekage current.

Erstellt von PISCEAN 2010 am 03.05.2012 11:15 (2 Antworten)

  03.05.2012, 11:15

PISCEAN 2010 Beigetreten am: 23.04.2010 Letzter Besuch: 20.05.2013 Beiträge: 1148 Bewertung:  (53)

(0)  Hello Experts, On one of the old HBM machine, Dc motor leakge current varies between 1.5 A to 3.5 Amp depending upon loading. Checked insulation resistance of field, armarure with body, found more than 50 M ohm at 500 V. Between, armatur & field more than 50 Mohm at 500 V. Field voltage is 190 V 1.8 Amp, armature voltage is 400 Volt, 23 Amp. What could be the problems? Thanks in advance. DEEP. Tell me and I will forget. Show me and I will remember. Involve me and I will understand. -Confucius

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  17.05.2012, 21:43

Mr_Al Beigetreten am: 29.12.2011 Letzter Besuch: 07.06.2012 Beiträge: 32 Bewertung:  (4)	(0)  Just an idea! In what direction is the current flowing? Is it flowing to the drive from the controller or from the drive to the motor? The motor earth connection could be  the earth for the whole control because of a bad earthing connection back in the control panel. atb as
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  18.05.2012, 06:49

PISCEAN 2010 Beigetreten am: 23.04.2010 Letzter Besuch: 20.05.2013 Beiträge: 1148 Bewertung:  (53)

(0)  Hello, Thanks for your keen interest & reply. Yes I have checked for proper earthing & confirmed that the current flows from motor to earth. Even to confirm this, I connected separate earth to motor & measured the current.   Basically I am unable to understand the reason behind this leakage current. According to my best knowledge, leakage current can flow only in case of bad or poor insulation. But in this case, the insulation resistance measured is quite good & within acceptable values. Moreover  megger, the instrument by which insulation resistance is measured is also in OK condition. Till don't know the reason behind it. Any guess, what could be the culprit?    Tell me and I will forget. Show me and I will remember. Involve me and I will understand. -Confucius

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