Reference Manual V1.10
Software Versions 3.xx
Page 16
X300-621-110
3.10. Connecting Shields
To obtain full EMC or for RFI immunity, cable shields MUST be connected to the earth lug on
the rear of the instrument.
3.10.1. Cable Shield Connection and Earthing
Care should be taken when connecting shields to maximise EMC or RFI immunity and
minimise earth loops and cross-talk (interference) between instruments.
For full EMC or for RFI immunity, termination of the cable shields at the earth lug is very
important. The earth lug of the instrument must be separately connected to ground
potential via a reliable link.
The instrument should only be connected to earth via a single reliable link to avoid earth
loops.
Where each instrument is separately earthed, interconnecting cable shields should be
connected at one end only. This also applies to communications cable shields in Ring
Networks, refer to Short Ring Network and Long Ring Network connections under ‘RS-
232 Serial
Caution:
Some load cells connect the cable shield directly to the load cell (and therefore
the scale base). Connection of the load cell cable shield in this situation may be site
specific.
3.11. Regulatory Sealing Requirements
To comply with regulatory sealing requirements for each instrument, (ie. to ensure instruments are
not accidentally or deliberately tampered with), it is important that proper sealing procedures be
adhered to. Refer to Appendix - Trade Sealing page 49 for more information.