Omron SYSDRIVE MX SERIES User Manual page 44

2-3 Wiring
Installing an AC Reactor
•If the Inverter is connected to a large-capacity power transformer (660 kVA or more) or the phase
advance capacitor is in use, a large peak current may flow through the input power circuit, causing
the converter unit to break down.
•Install an optional AC reactor on the input side of the Inverter. An AC reactor will also improve the
power factor of the power input side.
2
Installing a Surge Absorber
•Always use a surge absorber or diode when magnetic contactors (MC), electromagnetic relays,
solenoid valves, solenoid, and magnetic brakes are used.
Connecting a Regenerative Braking Unit
When running a load with a large inertia or a vertical axis, regenerative energy will return to the
Inverter.
If overvoltage in the main circuit is generated during deceleration, this indicates that the
regenerative energy exceeds the capacity of the Inverter. In this case, use a regenerative braking
unit.
•When using a regenerative braking unit, be sure to include a sequence whereby the power supply
for the Inverter will be turned off in the event of abnormal overheating. Not doing so may result in
fire.
Power supply
* Terminal symbols for 3G3MX-AE
<Braking Resistors and Braking Resistor Units for the Inverter>
Regenerative
2-19
For a regenerative braking unit: Use the error contact output (MA, MB).
Molded case
circuit-breaker
MC
(MCCB)
XB OFF ON
MC
Name Model
3G3AX-RBU21
3G3AX-RBU22
braking unit
3G3AX-RBU41
Magnetic contactor
(MC)
R/L1 (L1)
S/L2 (L2)
T/L3 (N/L3)
MC
MA
SA
MB
MC Regenerative braking unit
SA
are indicated in parentheses ( ).
3/1-phase
200 V
3-phase
400 V
Inverter
3G3MX
N/- P/+2 +1
N P
DCL
DC reactor
P RB R1 R2
Specifications
For general use (with built-in
resistor)
For heavy instantaneous
regenerative power (with built-in
resistor)
For general use (with built-in
resistor)