EMC Tests

CONFIGURATION OF THE 1^stTEST:

Data cable in an external electromagnetic field
A data cable (Category 5e UTP) is placed in an insulated anechoic chamber and subjected to a powerful artificially-generated electromagnetic field in order to simulate electromagnetic interference.

Each tray is connected to earth and subjected to the test:

Results and interpretations
A simple comparison of the measurements for the different cable tray configurations (wire mesh and perforated tray, with and without cover) makes it possible to quantify the role played by the tray in terms of EMC.

These tests show that there is no significant difference in "Faraday cage" effect offered by wire mesh or perforated cable tray.

These results show that is vital:
- To use metal tray
- To earth the cable tray
- To use a cover if required

Non metallic cable trays (PVC, composite materials) are ineffective against electromagnetic interference.

CONFIGURATION OF THE 2^ndTEST:

Data cable alongside a power cable
A category 6 UTP data cable is placed inside an insulated anechoic chamber and subjected to an electromagnetic field generated by a power cable. The following parameters are studied:
- Cable-tray earthing
- Separation distances: 0, 10, 20, 30 cm
- Cable-tray type: wire mesh, perforated tray, trunking
- Separated cable trays
- One cable trays, with and without dividers

As a result, a total of 118 configurations are tested

Results and interpretations
This second test configuration confirms that metal cable trays reduce interference (wire mesh or perforated tray).

To obtain a goog EMC, these results show that it is vital:
- To use metal cable tray
- To earth the cable tray

These tests show the importance of the following criterias:
- To ensure maximum separation distances
- To use two separate cable trays for power and data
- To use a divider if sharing containment systems

Never put power cables and data cables in the same closed compartment.