Ethernet Cables in PLC Control Cabinets

[tom baker]

A common application is to have ethernet connected devices (PLC's and flat panel displays) in a PLC cabinet, which is UL 508 listed.
Typically the system integrator (who builds the PLC cabinet) runs the ethernet cables in the wiring trough with 120V power.
A ethernet cable is an Art 725 Class II application, and is not allowed in the same raceway, enclosure or box, with power and lighting.
Does UL508 allow ethernet cables in the wiring trough with 120V power?

 

[petersonra]

Re: Ethernet Cables in PLC Control Cabinets

its not an article anything. it is completely outside the scope of the nec.

 

[jim dungar]

Re: Ethernet Cables in PLC Control Cabinets

In most cases the requirements of UL508A can be met by following NEC practices. Very rarely does UL have lower standards.

UL508A 29.5.1a requires insulation for maximum voltage. 44.1.4 says Class 2 circuits for information technology equipment must meet UL1950. But that is the closest it comes to ethernet cabling.

 

[justdavemamm]

Re: Ethernet Cables in PLC Control Cabinets

Originally posted by tom baker:

Typically the system integrator (who builds the PLC cabinet) runs the ethernet cables in the wiring trough with 120V power.

Then typically I will have them remove it from there and run it away from any power wires as best they can.

When I was a S.I., we always routed the ethernet/devicenet/serial communications cable outside the panudit / wireway, mainly to help avoid any noise problems.