Hitachi SJ300-037HFE 사용자 설명서

SJ300 Inverter

T

roub

leshooting

and Maintenance

The following procedure will check the inverter transistors (IGBTs) and diodes:

1. Disconnect input power to terminals [R, S, and T] and motor terminals [U, V, and W]. 
2. Disconnect any wires from terminals [P] and [RB] for regenerative braking.
3. Use a Digital Volt Meter (DVM) and set it for 1 ohm resistance range. You can check the 

status of the charging state of terminals [R, S, T, U, V, W, RB, P, and N] of the inverter and 
the probe of the DVM by measuring the charging state.

Almost infinite ohms = “non-conducting,” and 0 to 10 ohms = “conducting.”

NOTE: The resistance values for the diodes or the transistors will not be exactly the same, but 
they will be close. If you find a significance difference, a problem may exist.

NOTE: Before measuring the voltage between [P] and [N] with the DC current range, confirm 
that the smoothing capacitor is discharged fully, then execute the tests.

Converter

D1

R

PD

Non-conducting

PD

R

Conducting

D2

S

PD

Non-conducting

PD

S

Conducting

D3

T

PD

Non-conducting

PD

T

Conducting

D4

R

N

Conducting

N

R

Non-conducting

D5

S

N

Conducting

N

S

Non-conducting

D6

T

N

Conducting

N

T

Non-conducting

Inverter

TR1

U

P

Non-conducting

P

U

Conducting

TR2

V

P

Non-conducting

P

V

Conducting

TR3

W

P

Non-conducting

P

W

Conducting

TR4

U

N

Conducting

N

U

Non-conducting

TR5

V

N

Conduct

N

V

Non-conducting

TR6

W

N

Conducting

N

W

Non-conducting

Dynamic 

Braking

(0.4kW–11kW)

TR7

RB

P

Non-conducting

P

RB

Conducting

RB

N

Non-conducting

N

RB

Non-conducting

D1

D2

D3

D4

D5

D6

TR1

TR2

TR3

TR4

TR5

TR6

C

TR7

+

Converter

Inverter