Toshiba T2N - Manual (Page 77)

4.Installation and Wiring
62 PROSEC T2N
1. Separate the expansion cables as far as possible from other cables. In
particular, isolate them at least 200mm from power lines.
2. 4 types of expansion cables are available - 0.3m, 0.5m, 0.7m and 1.5m.
Select according to the positions of the units.
Grounding Point
It is advisable, for the grounding of electronic devices to carry out dedicated
grounding which is isolated from that of power systems, and to carry out
single-point grounding between 2 or more electronic devices. In the T2N,
noise-proofing is designed which takes the actual application into account, and
it has a satisfactory noise-immunity without carrying out grounding of the device
itself. However, as a precaution, correct grounding is recommended from the
viewpoint of reliability.
Carrying out grounding, check against the following criteria.
(1) The electronic equipment case must not become a path for a ground
current. (High-frequency currents are particularly harmful)
(2) Equalise the ground potentials when 2 or more units of electronic
equipment are to be connected. (Single-point grounding is best)
(3) Do not connect to power system earths. (High-frequency isolation is
necessary)
(4) Do not connect to unstable earths. (parts with unstable impedance such
as painted screws, and parts subject to vibration)
4.5
Grounding
NOTE