Anytime sensitive loads are used, great care should be taken to ensure the
wiring and grounding are appropriate. Every aspect of the power system should
meet, or exceed, the National Electrical Code requirements. It is important to
realize that the Code is not concerned with power quality, rather its concern is
with safety. If the Code says rigid metal conduit systems make an acceptable
ground, it's OK to still run a separate ground conductor.
In the case of local area networks (LANs), grounding is even more important. In computers, the internal digital reference is usually tied directly to the input power ground. Therefore, the digital reference of PC #1 on the LAN is the outlet it is plugged in to. The same applies to PC #2. If a voltage difference exists between these two ground points, then current will flow through the data cable connecting the two PCs. This can disrupt data flow, cause data errors, and even damage the I/O ports of the PCs.
If wiring is found that violates the Code, it should be fixed immediately. Oftentimes, bringing the electrical system up to Code resolves many power quality problems.
If poor grounding is a concern, the use of isolated ground receptacles, isolated ground busses in the panel, and isolated ground conductors will alleviate most problems.
When an isolated ground conductor is used, it should be run in the same raceway as the power conductors, and terminated at the neutral-to-ground bond of the power source. This source is the transformer or service entrance directly feeding the loads.
Using ground rods for grounding sensitive electronic devices inside the building is not recommended.
