User Manual
EM303A General Purpose Inverter
27
z
If single MCCB is shared by two or more inverters or other devices, the contact
of fault output relay shall be connected to power contactor coil, so that the power
supply will be turned off by the fault signals, as shown in Figure 3-4.
Figure 3-4 Connecting to Input Circuit Breaker
Installing a Leakage Circuit Breaker
High frequency leakage current is generated by high frequency PWM signal output
of inverter. Select a special purpose leakage breaker with a trigger current
≥
30mA.
For a regular leakage breaker, the trigger current
≥
200mA and the active time at
0.1S or above.
Installing an Electromagnetic Contactor
Install an electromagnetic contactor which is applicable to inverter as shown in
Figure 3-4.
z
Start/stop of the inverter can be controlled by the electromagnetic contactor on
input side. Inverter may break down if the electromagnetic contactor is on and off
frequently. The operation interval between start and stop of the inverter shall
≥
30
minutes, if electromagnetic contactor on input side must be used for controlling.
z
The inverter will not automatically start if power is on after failure.
Connecting to the Terminal Block
Power input phase sequence is not related to the phase sequence of terminals R, S,
and T on the terminal block, any two of them can be connected randomly.
Installing an AC Reactor
If the inverter is connected to a transformer with big-capacity (
≥
600kVA), or power
supply is connected to capacitive load, an excessive big surge current will occur
and rectifier of inverter can be broken down. Install an optional 3-phase AC reactor
on input side of inverter to suppress peak current and voltage, and improve power
factor of the system.
MCCB
ON
OFF
MC
MC
EC
EB
R
S
T
Fault Relay
Contact
EM303A