Hitachi SJ300 Series manual 142

4–4

Optional Controlled Decel and Alarm at Power Loss

Optional Controlled Decel and Alarm at Power Loss

Operations and Monitoring

With the default SJ300 inverter configuration, a sudden power loss will cause the inverter to shut down immediately. If running at the time, the motor and load will coast to a stop. And without power, the inverter’s alarm output will not activate. This default performance may be fine for applications with loads such as fans and pumps. However, some loads may require controlled decelerations upon power loss, or you may want an alarm signal upon power loss. This section describes how to harness regenerative energy so that the motor/load actually powers the inverter long enough to control a final deceleration and power the alarm output.

The diagram below shows the default configuration. Chapter 2 covered wiring the power source to the inverter input and the inverter output to the motor. By default, the inverter’s internal control circuit gets its power from two phases (R and T) from the input. The user-accessible 2-wire jumper (R–R0 and T–T0) connects input power to the control circuit.

Power source,

SJ300

3-phase

Converter

L1

R

DC bus

U

T1

L2

S

Rectifier

+

Inverter

V

T2

Motor

L3

T

–

W

T3

J51

T

+

P

Ferrite

R

PD

To optional

filter

R0

RB

braking resistor /

Control

–

braking unit

N

T0

circuit

2-wire

jumper

AL1

To external

AL0

alarm circuit or

AL2

interface

To provide power to the control circuit after input power loss, you must change the control circuit wiring as shown below (steps provided on following page).

Power source,

3-phase

Converter

SJ300

L1

R

DC bus

U

L2

S

Rectifier

+

Inverter

V

Motor

L3

T

–

W

J51

T

+

P

R

PD

To optional

RB

2-wire

R0

–

N

braking resistor /

Control

braking unit

jumper,

T0

AL1

20AWG

circuit

To external

Ferrite

AL0

alarm circuit or

filter

AL2

interface