2-16
2-2 Wiring
2
Design
Main Circuit Connection Diagram
* For 3G3JX-AE's terminal symbols, R/L1 corresponds to L1, S/L2 to L2, and T/L3 to N/L3.
Wiring the Main Circuit Terminals (Input Side)
Installing a Molded-case Circuit Breaker (MCCB)
•Always connect the Inverter and power supply via a molded-case circuit breaker (MCCB) to protect
the Inverter from damage that may result from short-circuiting.
•Always connect the power input terminals (R/L1, S/L2, and T/L3) and power supply via an MCCB,
according to the Inverter capacity.
•Install one MCCB per Inverter.
•Choose an appropriate MCCB capacity according to the fuse size on page 2-13.
•When choosing MCCB's time characteristics, be sure to consider the Inverter's overload protection
(1 minute at 150% of the rated output current).
•By programming the sequence as illustrated below, you can turn off the power via the relay outputs
(MA, MB, and MC) for the 3G3JX Series.
* For 3G3JX-AE's terminal symbols, R/L1 corresponds to L1, S/L2 to L2, and T/L3 to N/L3.
Installing a Ground Fault Interrupter
•The Inverter's output uses high-speed switching, and so generates high-frequency current
leakage. (Generally, if the power cable is 1 m, the leakage current is approx. 100 mA per Inverter,
and approx. 5 mA is added per additional meter of the power cable.)
•At the power supply input part, install a special-purpose ground fault interrupter for Inverters that
excludes high-frequency leakage current and detects only the leakage current within a frequency
range that is hazardous to humans. (Choose a ground fault interrupter with a sensitivity current of
at least 10 mA per Inverter.)
•Alternatively, use a general ground fault interrupter with a sensitivity current of 200 mA or more per
Inverter, and with an operating time of 0.1 s or more.
R/L1
S/L2
T/L3 *
U/T1
V/T2
W/T3
Regenerative braking unit
P/+2 N/-
M
Molded case
circuit-breaker
(MCCB)
MC
AC reactor
noise filter
Fuse
Power supply
Inverter
3G3JX
R/L1
S/L2
T/L3 *
Molded-case
circuit breaker
(MCCB)
MC
Power supply
Inverter
3G3JX
OFF
ON
X1
X2
X1
X2
X1
MA
MC
(30 V DC, 50 mA max.
DC (24 V) relay