User Manual
EM303B General Purpose Inverter
27
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.
The inverter will not automatically start after power 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.
Installing a Surge Absorber
Install a surge absorber for inductive loads (electromagnetic contactors, solenoid valves,
solenoid coils, or electromagnetic circuit breakers) nearby the inverter.
Installing a Noise Filter on Power Supply Side
To filter noise transmitted between power cable and the inverter, andthe harmonic
distortion
of
power grid caused by the noise produced by the inverter.
A special purpose noise filter is required for the inverter.
Correct vs incorrect installations of noise filters as shown in Figure 3-6 and Figure 3-7.
MCCB
Special
Purpose
Noise Filter
Other
Control
Devices
EM303B
Inverter
IM
EMC
Figure 3-6 Correct Noise Filter Installation
MCCB
Regular
Noise
Filter
Other
Control
Devices
EM303B
Inverter
IM
MCCB
Regular
Noise
Filter
Other
Control
Devices
EM303B
Inverter
IM
(a)
(b)
Figure 3-7 Incorrect Noise Filter Installation