Hitachi CMU Series User Manual page 13

(chapter 3, page 3-4)
Dust or other foreign matter might accumulate on the connector, resulting in
poor contact. Immediately after the module is unpacked, perform the
mounting and wiring procedures.
To prevent the module from being damaged, observe the following precautions
when you mount or demount the module:
• Before mounting the module to the mount base connector, check that the
connector pins are properly aligned and not bent, broken, or soiled with dirt
or the like.
• Ensure that the module is parallel to the mount base vertical surface as
shown below when mounting. If you connect a module to or disconnect it
from its connector while it is tilted, the connector pins may become damaged.
• If the mount base is positioned overhead due to the employed enclosure
structure, use a stepladder or the like and mount the module squarely. If
you mount the module obliquely, the connector may become damaged.
Mount base
(chapter 3, page 3-5)
Do not disassemble or modify the module. Failure to observe this precaution
may result in a fire or cause the module to become defective or malfunction.
NOTICE
[Bad example]
Module
NOTICE
S-10
[Good example]