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Fieldbus in Non-Incendive/Division 2 Applications

Benefits
  • Up to 32 instruments / segments
  • Optional redundant Fieldbus power with Power Hub
  • Optional online physical layer diagnostics with Power Hub
  • High Power Trunk => maximum cable length
  • Nonincendive short circuit protected outputs
  • Live connect / disconnect of devices in Division 2
  • Worldwide approvals
High Power Trunk with Segment Protectors in a Nonincendive Application


Non Incindive Fieldbus
* Note: the maximum spur length per Fieldbus spec is 120m. Therefore, when using a Type A fieldbus cable, the L and C evaluation, (for practical purposes), can be eliminated, due to the short cable length. This reduces the evaluation to just Vmax >= Voc = Vout
Non-Incendive Applications

When using Fieldbus technology in non-incendive/Division 2 installations the installer must follow certain guidelines defined in the NEC and ANSI/ISA standards. Article 502.2 of the NEC defines the non-incendive words listed on the image and refers to ANSI/ISA 12.12.01-2000, Non-Incendive Electrical Equipment for Use in Class I and II, Division 2, and Class III, Division 1 and 2 Hazardous (Classified) Locations for further information. 

Section 7 of this standard, titled Non-incendive Circuits and Non-Incendive Field Wiring, defines the concept of matching parameters of the associated non-incendive field wiring apparatus with those of the non-incendive field wiring apparatus.

As shown here, live maintenance such as connecting / disconnecting a device under power on the spur connections can only be performed when these parameters are properly matched.