N-Tron 508TX Installation Manual

Also see for 500 Series: Installation guide

Contents

N-Tron 508TX Installation Manual Manual pdf 14 page image

(Revised 2013-06-21) 14N-Tron Switch Grounding TechniquesThe grounding philosophy of any control system is an integral part of the design. N-Tron switches aredesigned to be grounded, but the user has been given the flexibility to float the switch when required. Thebest noise immunity and emissions (i.e. CE) are obtained when the N-Tron switch chassis is connected toearth ground via a drain wire. Some N-Tron switches have metal din-rail brackets that can ground the switchif the din-rail is grounded. In some cases, N-Tron switches with metal brackets can be supplied withoptional plastic brackets if isolation is required.Both V- legs of the power input connector are connected tochassis internally on the PCB. Connecting a drain wire toearth ground from one of the V- terminal plugs as shownhere will ground the switch and the chassis. The powerleads from the power source should be limited to 3 metersor 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 anunused PEM nut to connect a ground lug via a machine screw, careshould be taken to limit the penetration of the outer skin by less than 1/4in. Failure to do so may cause irreversible damage to the internalcomponents of the switch. Please note that the minimum cross-sectional area of the grounding conductor must be at least 4mm2and it must be suitable for use in temperature of 110°C.Note: Ensure the power supply is grounded properly before applyingpower to the grounded switch. This may be verified by using avoltmeter to determine that there is no voltage difference between thepower supply’s negative output terminal and the chassis groundingpoint of the switch.If the use of shielded cables is required, it is generally recommended to only connect the shield at one end toprevent ground loops and interfere with low level signals (i.e. thermocouples, RTD, etc.). Cat5e cablesmanufactured 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 localcabinet and/or referenced to the same earth ground), it is permissible to use fully shielded cables terminatedto chassis ground at both ends in systems void of low level analog signals.