N-Tron 102PC-SE Manual Do Utilizador
12/1/2006
10
GROUNDING TECHNIQUES
The grounding philosophy of any control system is an integral part of the design. N-Tron switches are designed
to be grounded, but the user has been given the flexibility to float the switch when required. The best noise
immunity and emissions (i.e. CE) are obtained when the N-Tron switch chassis is connected to earth ground via
a drain wire. Some N-Tron switches have metal din-rail brackets that can ground the switch if the din-rail is
grounded. In some cases, N-Tron switches with metal brackets can be supplied with optional plastic brackets if
isolation is required.
to be grounded, but the user has been given the flexibility to float the switch when required. The best noise
immunity and emissions (i.e. CE) are obtained when the N-Tron switch chassis is connected to earth ground via
a drain wire. Some N-Tron switches have metal din-rail brackets that can ground the switch if the din-rail is
grounded. In some cases, N-Tron switches with metal brackets can be supplied with optional plastic brackets if
isolation is required.
Both V- legs of the power input connector are connected to
chassis internally on the PCB. Connecting a drain wire to earth
ground from one of the V- terminal plugs as shown here will
ground the switch and the chassis. The power leads from the
power source should be limited to 3 meters or less in length.
As an alternate,
chassis internally on the PCB. Connecting a drain wire to earth
ground from one of the V- terminal plugs as shown here will
ground the switch and the chassis. The power leads from the
power source should be limited to 3 meters or less in length.
As an alternate,
users can run a drain wire & lug from any of the Din-Rail
screws or empty PEM nuts on the enclosure. When using an
unused PEM nut to connect a ground lug via a machine screw,
care should be taken to limit the penetration of the outer skin
by less than 1/4 in. Failure to do so may cause irreversible
damage to the internal components of the switch.
The use of shielded cables between devices is not required for most N-Tron devices (please consult the user
manuals for specific details). If the use of shielded cables is required, it is generally recommended to only
connect the shield at one end to prevent ground loops and interfere with low level signals (i.e. thermocouples,
RTD, etc.). Cat5e cables manufactured to EIA-568A or 568B specifications are required for use with N-Tron
Switches.
screws or empty PEM nuts on the enclosure. When using an
unused PEM nut to connect a ground lug via a machine screw,
care should be taken to limit the penetration of the outer skin
by less than 1/4 in. Failure to do so may cause irreversible
damage to the internal components of the switch.
The use of shielded cables between devices is not required for most N-Tron devices (please consult the user
manuals for specific details). If the use of shielded cables is required, it is generally recommended to only
connect the shield at one end to prevent ground loops and interfere with low level signals (i.e. thermocouples,
RTD, etc.). Cat5e cables manufactured to EIA-568A or 568B specifications are required for use with N-Tron
Switches.
In the event all Cat5e patch cable distances are small (i.e. All Ethernet devices are located the same local
cabinet and/or referenced to the same earth ground), it is permissible to use fully shielded cables terminated to
chassis ground at both ends in systems void of low level analog signals.