Optional Controlled Decel And Alarm At Power Loss - Hitachi SJ7002 Series Instruction Manual

4–4

Optional Controlled Decel and Alarm at Power Loss

Optional Controlled Decel and Alarm at Power Loss
With the default SJ700 inverter configuration, a sudden power loss will cause the inverter to
2
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,
3-phase
L1
R
L2
S
L3
T
J51
T
R
Ferrite
filter
R0
T0
2-wire
jumper
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
L1 R
L2 S
L3 T
J51
T
R
2-wire
R0
jumper,
T0
20AWG
Ferrite
filter
SJ700
Converter
DC bus
+
Rectifier Inverter
–
+
Control
–
circuit
SJ700
2
Converter
DC bus
+
Rectifier Inverter
–
+
–
Control
circuit
2
T1
U
T2
V
Motor
T3
W
P
PD To optional
braking resistor /
RB
braking unit
N
AL1
To external
AL0
alarm circuit or
interface
AL2
U
V
Motor
W
P
PD
To optional
RB
braking resistor /
N
braking unit
AL1
To external
AL0
alarm circuit or
interface
AL2