General guidelines
The following guidelines should be observed regarding the power supply:
A surge limiter must be installed at the junction where the flex enters the building.
Disturbances to the mains power are dampened by industrial line filters installed at the entrance to the system.
Sensitive devices are protected by surge limiters and surge arresters at the input feed.
Transformers can also be used as filters. For high frequency disturbances the transformer must be equipped with single, or preferably double, shielding.
Example: Solution for the power supply
The following illustration shows an example of filtering the mains power by using a double isolated transformer:

Guidelines for partitioning in the system
The power supplies for the individual devices should be wired as point-to-point from the line entry:

Separate power supplies must be provided if extremely sensitive and high interference devices are used concurrently in the same power supply system:

Devices with high inference capabilities must be connected as close as possible to the line entry and sensitive devices connected at a distance from the line entry:
