Wattstopper Wireless DLM Now Available!

Intelligent. Secure. Scalable.

Watch the Video

Menu
Search
Menu

Electromagnetic Compatibility (EMC)
Understanding EMC involves the analysis of electromagnetic pollution between a source of disturbance and its victim.

Phenomenon
Electromagnetic disturbance is emitted by a source polluting a victim. The transmission of electromagnetic disturbance is known as coupling. An EMC problem only occurs when the three elements source, coupling and victim are evident. To obtain good EMC we simply need to eliminate one of the three elements or reduce its effect.

A metallic cable tray has excellent electrical continuity and is part of the equipotential earth network of the installation, it will reduce the impact of the coupling thereby participating in good EMC of the electrical installation.

In practice, the electrical system must be installed according to industry standards.



Electromagnetic Compatibility (EMC)

The three elements of an interference situation

Power cable

Mobile phone

Lightning

Frequency modulators

 

DATA Cables

Computer hardware

Devices



Best Practices to minimize EMC Potential 

Separate the power and DATA cables (20cm separation) 

Cables of different families should cross each other at right angles

Provide electrical continuity:
Metallic cable tray and low resistance couplers.

Connect the cable trays to earth network (15 to 20 metres)



The Cablofil® solution

  • Its open structure makes it easy to ensure correct cable separation by visual inspection.
  • Easy installation and metal structure guarantee excellent electrical continuity in all cases: couplings, bends, level changes, crossing walls, etc.
  • Electrical Continuity and proper cable separation can reduce crosstalk dramatically.

 

 EMC Tests
Carried out in independent and accredited laboratories, AEMC Mesures and CETIM, these tests demonstrate the performance of Cablofil® in regard to the EMC of the electrical installation.
 
 
1st test configuration
  Data cable subjected to an external electromagnetic field.
A UTP category 5e cable, placed in an insulated chamber, is subjected to a severe electromagnetic field, simulating electromagnetic disturbance. Each different type of metal cable tray, connected to earth, is tested:
 
        Results and interpretations
 

The comparison of the results of each configuration of cable tray, wire mesh and perforated tray, with and without cover, shows the EMC performance of cable tray.
These tests show that there is no significant difference in the "Faraday cage" effect offered by wire mesh of perforated cable tray.
These results show that it is vital:

  • To use metal cable tray
  • To earth the cable tray
  • To use a cover if required

 


Non metallic cable tray (PVC, composite material) has no effect against electromagnetic  disturbances.
 
 
 
2nd test configuration
 

Data cable alongside a power cable
A UTP category 6 cable, placed in an insulated chamber, is subjected to an electromagnetic field created by a power cable.  The following parameters are studied:

  • Impact of earthing
  • Separation distance : 0,10,20,30 cm
  • Type of containment: wire mesh, perforated tray and trunking
  • Separated cable trays
  • One cable tray with divider
  • One cable tray with divider and without divider

118 configurations were tested

 
 
       Results and interpretations
 

This 2nd test configuration confirms the attenuation effect of a metallic cable tray irrespective of its design (wire mesh or perforated tray).
Best Practices

  • Always use metal cable tray
  • Properly Ground/Bond the tray
  • Ensure maximum separation distances
  • Use two separate cable trays for power and data if possible
  • Always use a divider if sharing cable containment systems

 

Never mix power cables and data cables in a trunking system
 
 
Conclusion
 
 
 

When the Cablofil® "steel wire" cable tray is integrated in the earth or building network, it helps to contribute to enhanced electromagnetic compatibility in an electrical installation.

Independent tests show that in practice, the shape, pattern or type of cable tray has no significant impact on its EMC shielding capability.