BeiJer iX Panel T4A - 6.2 Ethernet Connection Grounding

Additional Installation Tips
6.2 EthernetConnectioninthePanel
1
2
3
4
5
1-1
2-2
3-3
8-8
RJ45
RJ45
RJ45
RJ45
RJ45
RJ45
RJ45
RJ45
Industrial Ethernet
Operator panel
Operator panel
Operator panel
Operator panel
Shielded
Short and
unshielded
0.1 uF
250 V
5351
In some industrial units for Ethernet, the RJ45 contact’s shield is connected to the
chassis via a capacitor, see 1 in drawing above.
The operator panel’s Ethernet shield is directly
connected to the chassis, see 2 in
drawing above.
1.
Check whether the other Ethernet unit has its shield directly grounded or
grounded via a capacitor.
Note:
Inmanycases,connectingtheshieldedEthernetcablingtothechassisatbothendsis
inappropriate. Humorgroundingloopscanoccur. Unshieldedcablingmayevenresult
infewercommunicationerrors.
A good solution may be to use a shielded Ethernet cable, but to co nnect the shield
at one end only.
One option is to break the shield, see 3 in drawing above.
A more elegant method is to expand the shielded Ethernet cabling with a p iece of
unshielded Ethernet cable, see 4 in drawing above.
You can ground the shield via an external 0.1 uF/250 V plastic capacitor, see 5 in
drawing above. This will connect the HF transients to the ground.
BeijerElectronics, MAEN015A
18