Delta MS300 Series User Manual page 92

7-5-1 Installation
During installation, pass the cable through at least one zero phase reactor. Use a suitable cable type
(pressure endurance, current endurance, insulation class, and wire gauge) so that the cable passes
easily through the zero phase reactor. Do not pass the grounding cable through the zero phase
reactor; only pass the motor wire and power cable through the zero phase reactor. With longer motor
cables the zero-phase reactor can effectively reduce interference at the motor output. Moreover, pay
extra attention to the large leakage current due to long cable length. This may cause temperature rise
in the zero phase reactor. Install the zero phase reactor as close to the output of the drive as possible.
Figure 7-23 below shows the installation diagram for a single turn zero phase reactor. If the wire
diameter allows several turns, Figure 7-24 shows the installation of a multi-turn zero phase reactor.
The more turns, the better the noise suppression effect.
Single turn wiring diagram for shielding wire with a zero phase reactor
7-5-2 Installation Precaution
Install the zero phase reactor at the drive's output terminal (U/T1, V/T2 and W/T3). After the zero
phase reactor is installed, it reduces the electromagnetic radiation and load stress emitted by the
wiring of the drive. The number of zero phase reactors required for the drive depends on the wiring
length and the drive voltage.
The normal operating temperature of the zero phase reactor should be lower than 85°C (176°F).
However, when the zero phase reactor is saturated, its temperature may exceed 85°C (176°F). In this
case, increase the number of zero phase reactors to avoid saturation. The following are reasons that
might cause saturation of the zero phase reactors: the drive wiring is too long; the drive has several
sets of loads; the wiring is in parallel; or the drive uses high capacitance wiring. If the temperature of
the zero phase reactor exceeds 85°C (176°F) during the operation of the drive, increase the number
of zero phase reactors.
Figure 7-23
Figure 7-24
Multi-turn zero phase reactor
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Chapter 7 Optional AccessoriesMS300