
3.INSTALLATION B-63943EN/02
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3.5.6 Measures Against Surges due to Lightning
To protect the devices from surge voltages due to lightening, it is
recommended to install surge-absorbing elements between the lines of
the input power and between one line and ground. This does not,
however, assure protection from all surges due to lightening.
The recommended items are as follows. (Items made by Okaya
Denki Sangyo Co.)
For the 200-V system
Between lines R⋅A⋅V-781BYZ-2
Between line and ground R⋅A⋅V-781BXZ-4
For the 400-V system
Between lines R⋅A⋅V-152BYZ-2A
Between line and ground R⋅A⋅V-801BXZ-4
Installation procedure
The surge-absorbing elements used for measures against surges due to
lightening must be installed in the input power unit as shown in the
figure below. The figure below shows an example in which an
insulating transformer, shown by dotted lines, is not installed. If an
insulating transformer is installed, surge-absorbing element 2
(between line and ground) is not required.