5.5 How to check inverter & converter portion

Inverter and converter module can be checked by using a tester.

(Preparation)

(1)Disconnect all the connected wires and devices to the power terminals (R, S, T, U, V, W, P and RB). (2)Tester is to be set as 1ohm range.

(How to check)

Check the ON condition of each point shown below.

(note 1) Be sure to discharge DC bus voltage beforehand, which should be checked by DC bus voltage. (note 2) Normally, the resistance shows in case of OFF mode.

In some cases resistance does not show due to the capacitance of DC bus capacitors.

Resistance shows 3ohm ~ 50ohm (depends on the tester voltage) in case of ON mode.

Resistance values may not be completely the same due to the electrical device (IGBT chip, diode chip…) difference. But we can regard the result is okay if all the data are nearly the same.

 

 

 

 

 

Tester polarity

 

 

 

 

 

(Red)

 

 

(Blk)

 

 

 

 

 

 

 

D1

 

 

 

R

 

 

PD

 

 

 

PD

 

 

R

 

 

 

 

 

 

 

D2

 

 

 

S

 

 

PD

 

 

 

PD

 

 

S

 

 

 

 

 

 

Converter

D4

 

 

 

T

 

 

PD

 

 

 

N

 

 

R

 

D3

 

 

PD

 

 

T

 

 

 

 

 

R

 

 

N

 

D5

 

 

 

S

 

 

N

 

 

 

 

 

 

 

 

 

 

N

 

 

S

 

 

 

 

 

 

 

 

D6

 

 

 

T

 

 

N

 

 

 

 

N

 

 

T

 

 

 

 

 

 

 

 

TR1

 

 

 

U

 

 

P

 

 

 

 

P

 

 

U

 

 

 

 

 

 

 

 

TR3

 

 

 

V

 

 

P

 

 

 

 

P

 

 

V

 

 

 

 

 

 

 

Inverter

TR4

 

 

 

W

 

 

P

 

TR5

 

 

 

P

 

 

W

 

 

 

 

 

 

 

 

 

 

 

 

U

 

 

N

 

 

 

 

 

N

 

 

U

 

TR6

 

 

 

V

 

 

N

 

 

 

 

N

 

 

V

 

 

 

 

 

 

 

 

TR2

 

 

 

W

 

 

N

 

 

 

 

N

 

 

W

 

 

 

 

 

 

 

 

 

 

 

RB

 

 

P

BRD

TR7

 

 

 

P

 

 

RB

 

 

RB

 

 

N

 

 

 

 

 

N

 

 

RB

 

 

 

 

 

A

 

 

K

Thyristor

 

 

 

 

A

 

 

G

THY

 

 

 

K

 

 

A

 

 

 

 

 

 

 

 

 

 

K

 

 

G

 

 

 

 

 

 

 

 

 

 

 

 

G

 

 

A

 

 

 

 

 

G

 

 

K

ON; Low resistance

OFF; High resistance

Measure ment

OFF

ON

OFF

ON

OFF

ON

ON

OFF

ON

OFF

ON

OFF

OFF

ON

OFF

ON

OFF

ON

ON

OFF

ON

OFF

ON

OFF

OFF

ON

OFF

OFF

OFF

OFF

OFF

ON

OFF

ON

 

 

PD

P

RB

 

 

 

Converter

 

 

 

Inverter

 

 

 

 

 

 

 

TR1

TR3

TR5

D1

D2

D3

 

 

 

 

 

 

 

THY

 

 

 

 

 

R

 

 

 

 

 

 

 

 

 

 

 

 

 

 

U

S

 

 

 

 

 

 

V

 

 

 

 

C+

 

 

 

 

 

 

 

 

 

T

 

 

 

 

 

 

W

 

 

 

 

 

 

 

D4

D5

D6

 

 

 

 

 

 

 

 

 

TR7

TR4

TR6

TR2

 

 

 

N

BRD

 

 

 

 

 

 

 

 

 

 

Thyristor portion

A

K

 

G

5- 4

Page 33
Image 33
Hitachi L300P Series service manual How to check inverter & converter portion