Delta Compact Drive MS300 IP66/NEMA 4X Series, User Manual

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Chapter 7 Optional Accessories

MS300 (IP66 / NEMA 4X)
7-7
7-4 AC/DC Reactor
AC Input Reactor (IP Level: IP00)
Installing an AC reactor on the input side of an AC motor drive can increase line impedance, improve
the power factor, reduce input current, and reduce interference generated from the motor drive. It also
reduces momentary voltage surges or abnormal current spikes. For example, when the main power
capacity is higher than 500 kVA, or when using a switching capacitor bank, momentary voltage and
current spikes may damage the AC motor drive’s internal circuit. An AC reactor on the input side of the AC
motor drive protects it by suppressing surges.
Installation
Install an AC input reactor in series between the main power and three input phases R / L1, S / L2, T /
L3, as shown in the figure below:
Connecting an AC input reactor
AC Output Reactor (IP Level: IP00)
When using drives in long wiring output application, ground fault (GFF), over-current (OC) and motor
over-voltage (OV) often occur. GFF and OC cause errors due to the drive's self-protective mechanism;
over-voltage damages motor insulation.
The excessive length of the output wires makes the grounded stray capacitance too large, increase
the three-phase output common mode current, and the reflected wave of the long wires makes the motor
dv / dt and the motor terminal voltage too high. Thus, installing a reactor on the drive’s output side can
increases the high-frequency impedance to reduce the dv / dt and terminal voltage to protect the motor.
Installation
Install an AC output reactor on the output side of the drive, as shown in the figure below:
Connecting an AC output reactor