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SJ300 Inverter
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CAUTION: MOTOR TERMINAL VOLTAGE SURGE SUPPRESSION FILTER
(For 400 V CLASS Inverters)
In a system using an inverter with the voltage control PWM system, a voltage surge caused by
the cable constants such as the cable length (especially when the distance between the motor
and inverter is 10 m or more) and cabling method may occur at the motor terminals. A
dedicated filter of the 400 V class for suppressing this voltage surge is available. Be sure to
install a filter in this situation. (See “LCR filter” on page 5–2, part type HRL–xxxC.)
CAUTION: EFFECTS OF POWER DISTRIBUTION SYSTEMS ON INVERTERS
In the cases below involving a general-purpose inverter, a large peak current can flow on the
power supply side, sometimes destroying the converter module:
1. The unbalance factor of the power supply is 3% or higher.
2. The power supply capacity is at least 10 times greater than the inverter capacity (or the
power supply capacity is 500 kVA or more).
3. Abrupt power supply changes are expected, due to conditions such as:
a. Several inverters are interconnected with a short bus.
b. A thyristor converter and an inverter are interconnected with a short bus.
c. An installed phase advance capacitor opens and closes.
Where these conditions exist or when the connected equipment must be highly reliable, you
MUST install an input-side AC reactor of 3% (at a voltage drop at rated current) with respect to
the supply voltage on the power supply side. Also, where the effects of an indirect lightning
strike are possible, install a lightning conductor.
CAUTION: Do not install inverters in a corner-grounded Delta distribution system. The result-
ing line imbalance will cause premature line fuse failure and failure of the inverter input bridge
rectifier. Install in a balanced Delta or Wye distribution system only.
CAUTION: When the EEPROM error E8 occurs, be sure to confirm the setting values again.
CAUTION: When using normally closed active state settings (C011 to C019) for externally
commanded Forward or Reverse terminals [FW] or [RV], the inverter may start automatically
when the external system is powered OFF or disconnected from the inverter! So, do not use
normally closed active state settings for Forward or Reverse terminals [FW] or [RV] unless
your system design protects against unintended motor operation.
General Caution
CAUTION: In all the illustrations in this manual, covers and safety devices are occasionally
removed to describe the details. While operating the product, make sure that the covers and
safety devices are placed as they were specified originally and operate it according to the
instruction manual.