Hitachi L100-004 HFE Manual page 12

well apart from the inverter. It is also effective to shield the whole inverter structure
(refer to figure below, left part).
Noise
Remote
operator
Completely ground the frame
with as short a wire as possible.
Addition of an EMI filter on the input side of the inverter also reduces the effect of
noise from commercial power lines on external devices (refer to figure above).
CAUTION EFFECTS OF DISTRIBUTER LINES ON INVERTERS
In the cases mentioned below involving a general purpose inverter, a large peak
current flows on the power supply side, sometimes destroying the converter module:
A) The unbalance factor of the power supply is 3% or higher.
B) The power supply capacity is set at least ten times greater than the inverter
capacity (i.e. 500kVA or more)
C) When abrupt power supply changes are to be expected. Some examples:
1) Several inverters are interconnected using a short bus to the same power
supply.
2) A thyristor converter and an inverter are interconnected using a short bus.
3) An installed power factor compensating device is connected or disconnected.
In the cases mentioned above we recommend installing an AC reactor of 3% voltage
drop at rated current with respect to the supply voltage on the power supply side.
When an EEPROM error occurs (trip E 08) all parameter values have to be checked
CAUTION
for correctness (especially the RS input).
CAUTION When the intelligent digital inputs FW or RV are configured as normally closed
contact (standard setting is normally open), then the inverter starts automatically. Do
not configure these inputs as normally closed inputs unless absolutely necessary.
GENERAL NOTICE
In all the illustrations and figures in this manual, covers and safety devices are
occasionally omitted in order to better describe the details. When the inverter is
operated make shure that all the covers and safety devices are placed in their correct
positions.
Grounded piping
or shielded wire
Motor
Noise
Grounded
frame
1-4
Chapter 1 – Safety precautions
Inverter
EMI filter
R1 R2 L1(L1) T1(U)
S1 S2 L2 T2(V)
T1 T2 L3(N) T3(W)
Grounding
Motor