Wednesday, January 3, 2024

Test IGBT with Multimeter BAD or Good Condition

Test    IGBT    with    Multimeter 

How  to  test  IGBT with  multimeter , it  will explain on  this article.   If  anyone  can  use  a  basic  multimeter and  know  how  to  test diode , it can easily test  IGBT  too.  Before  testing  notice  the IGBT terminals , It has  G ,  C and  E terminal.  G = Gate ,  C= Collector,  E = Emitter.   Some model  of   IGBT has internal diode connected  across  C and E terminal.  Hight current  and  big IGBT tend to  fail  as shorted and open condition so  before testing all process you may firstly check  shorted and open condition.


IGBT  Symbol

IGBT   test  with   multimeter

 Discharge IGBT by shorting 3 terminal together.  This sample IGBT  has terminal arrangement  as   G   C   E  ( 1-2-3 respectively ).


Test    IGBT   Part   1

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Choose   these  articles   to  read .


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Step  to  Test  IGBT   with  a   multimeter .

1.  Discharge IGBT by shorting 3 terminal together. Use resistor legs or other similar metal wire.  After discharge do not touch any its terminal and during the test process always hold at insulated area or black case.   Remove  IGBT  from circuit  before doing  any any  testing.

2.  Test  C and  E  terminals by using Rx1K   Ohm range.  Touch the test lead and read the measured value.   Switch the test lead and   read the measured value again.   Good  IGBT  will  display some resistance  1 time  and  ∞  1  time.  Shored  IGBT will point at 0 Ohm  2 time.  Open IGBT  will point at ∞    2   time.


Test   IGBT    with multimeter       万用表
                    Good  IGBT  will   point  at  some resistance  1 time .



Test  IGBT   with multimeter
                 Good   IGBT  will   point   at   ∞   scale     1  time 


3.  Test  G and  C  terminals by using Rx10K   Ohm range.  Touch the test lead and read the measured value.   Switch the test lead and  read the measured value again.    Good IGBT  will  display  ∞   2   time.

4.  Test  G and  E  terminals by using Rx10K   Ohm range.  Touch the test lead and read the measured value.   Switch the test lead and read the measured value again.   Good  IGBT  will  display  ∞  2   time.

                                      

Test   IGBT

                     Test  G and  C   terminals   by using   Rx10K   Ohm range.


Test   IGBT   with multimeter

                     Test  G and  E   terminals by using   Rx10K   Ohm range.


All step  1 ,  2  ,  3 to 4 testing must    be good condition so the IGBT is good condition.  If any of  only 1 step is  fail so the IGBT is already bad.


Simple   method  to test IGBT  is   Gate  trig.

Discharge the IGBT by shorting 3 terminal together. During the test process do not touch any terminal and always hold  IGBT at  black case.    Connect the lest lead  as photo then use resistor to supply trig voltage from C terminal to trig G terminal.   Good IGBT will cause  pointer  of   multimeter  move  forward and point at some resistance.  then remove  the resistor ( trig voltage) ,  the IGBT still let current flow and the pointer still  point  at  the same position  when  trig  Gate.

Test   IGBT    with multimeter

                                         Connection  of   test  leads  to trig  Gate  of   IGBT




Test   IGBT

              After removing  trig voltage , the pointer still point  the same position  ( for good IGBT)