
5. INSTALLATION
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To satisfy the EMC Directive, the installation of a noise filter is required
in the input section of the power magnetics cabinet.
The rated current of the noise filter being used is determined according
to the type of the CNC that is connected, the type and number of motors,
and the power consumption of the other peripheral devices. Using the
expression given below, calculate the noise filter load current, and select
a noise filter so that the load current does not exceed the rated current of
the filter. Recommended noise filters are given in (12) of Section 2.2.3.
Obtaining the load current of a noise filter
The load current of a noise filter is the sum of the CNC input current, PSM
input current, and current consumption under the other loads.
Load current
(Arms)
CNC input
current
(Arms)
PSM input
current
(Arms)
Current con-
sumption under
other loads
(Arms)
=+ Σ+
(Note 1) (Note 2)
NOTE
1 The CNC input current is determined by the number of
PSUs (power supply units). Calculate the CNC input current
from the following expression:
CNC input current (Arms) = 5 (Arms) x number of PSUs
Normally, a CNC has one PSU. The FS15 multiaxis control
system has two PSUs.
2 For details of how to obtain the PSM input current, see
Sections 4.1.1 or 4.2.1.
3 Attach a noise suppressor such as a spark killer to the
magnetic contactor driving coil. When more than one PSM
is connected, sum the input currents of the PSMs.
5.3.5
Selecting a Noise Filter