Installing Foundation Fieldbus H1 in Hazardous Areas Presented By: Jim Peterson Sr. Applications Engineer MTL/USA
(Divisions) (Zones) Zone 0 ia) Intrinsically Safe Class I Division 1 Explosion Proof Purged Intrinsic Safety Zone 1 (ia) and (ib) Intrinsically Safe (d) Flameproof (p) Pressurized (e) Increased Safety (q) Powder Filled (m) Encapsulation (o) Oil immersion Class I Division 2 All Types suitable for Division 1 and Nonincendive Zone 2 All types suitable for Zone 0 and 1 (n) Nonincendive Sub-catagories (na) Nonsparking Equip. (nc) Sparking Equip. with contacts protected (nr) Restricted breathing enclosure
What are the (Physical Layer) requirements for Hazardous Area FF H1 Installations?
A Hazardous Area Fieldbus Segment requires the following: An H1 Fieldbus Host A DC Bulk Power Supply certified for the area A certified Fieldbus Power Conditioner/ Barrier A set of 2 Terminators (1 at each end of a segment) integrated are acceptable Trunk and Spur cable certified for the area Certified (Spur Blocks) Field devices Certified for the area Spur Connectors (where appropriate)
Resides at the controller and will accept up to 32 FF Devices although a typical installation of a segment is less than 16 devices
A DC Power Source is required to supply the Power Conditioners 2 separate independent sources should power the Bulk Supplies AC line and Battery Backup or UPS typical Over-current protection should be provided for each feed supplying power to the FF Power Conditioners Negative Leg of supplies grounded Should be redundant
Power Conditioners must be used otherwise the power supply would absorb signals on the cable trying to maintain a constant voltage level (regulation). Power Conditioners use a circuit that allows the DC voltage on the wiring, but prevents the signal from being absorbed. Some Power Conditioners also provide other functions such as Intrinsic Safety or Repeater capabilities as with some FISCO Power Conditioner/Repeaters.
Matches impedance to eliminate reflections Two Required per Segment and for each repeated segment Terminators can be built into some devices such as the Power Conditioner/Repeaters 100 Ohms 1.0 μf
FISCO Field devices such as Transmitters and Valve Positioners,, Power Conditioners, and Inter-connecting active components (Spur Blocks with Short Circuit Protection), would have to comply with the Fieldbus Intrinsically Safe Concept (FISCO)
Point-to- Point Bus with Spurs Daisy-Chain Chicken foot
There are 2 ways to approach IS segments Entity Approach: FF816 Entity physical layer. This approach limits field devices to the allowable Capacitance and Inductance of the IS barriers as well as limiting the power available to the segment for these devices. Typically limited to a maximum of (80ma), 4 20ma field devices maximum FISCO Approach: FF816-FISCO The Fieldbus Intrinsically Safe Concept
Hazardous Area The Entity FF-816 approach Non- hazardous area SAFE AREA. 7 8 9 SAFE AREA HAZ. AREA HAZ. AREA 4 5 1 6 2 3 10 11 12 MTL5053 24vdc bulk supply
Fieldbus Intrinsically Safe Concept
FISCO (A&B) Power Conditioner/ Repeaters: Up to 6, 20ma FISCO field devices can be applied per Power Conditioner/Repeater in Gas Groups A&B Conditioners/Repeaters are seen by the host as a field device A total of 4 FISCO Conditioner/Repeaters can be used with a single input to an H1 host The maximum # of FISCO devices, (24 field devices), can then be applied in Class I, Division 1, Gas Group A using a single H1 control card
UPS Hazardous area Class I, Division 1 or Zone 0, Gas Group A with FISCO approved Field Devices 120VAC H1 Controller Non-Hazardous Area IS FISCO Repeater Isolators Div2/Zone 2 Redundant Bulk DC Supplies Div1/Zone 0 Spur Blocks, Terminators, and FISCO Field Devices
FISCO (C&D) Power Conditioner/ Repeaters: Up to 12, 20ma FISCO field devices can be applied per power conditioner/repeater Conditioners/Repeaters are seen by the host as a field device The use of up to 4, FISCO conditioners per H1 host is allowable The maximum # of FISCO devices (a fully loaded segment 28 field devices), may be used in gas groups C&D utilizing a single H1 control card
Hazardous area Class I, Division 1, Gas Group C&D with FISCO approved Field Devices UPS 120VAC H1 Controller Non-Hazardous Area IS FISCO Repeater Isolators Div2/Zone 2 Redundant Bulk DC Supplies Div1/Zone 0 Spur Blocks, Terminators, and FISCO Field Devices
Entity Approved FF H1 devices can be used on FISCO segments using Spur Connectors Spur Connectors were developed as a temporary solution to the situation of Entity and FISCO interconnection Several solutions are available for various applications and Area Classifications. The use of the Spur Connectors allow a flexible approach to the FISCO concept.
Non-Hazardous (SAFE) Area FISCO P/C Hazardous Div 2/Zone 2 Area Spur Connector Class I, Division 1/Zone1 FISCO Devices Entity Approved device
Fieldbus Non Incendive Concept
This allows Division 2/Zone 2 installations to take advantage of more relaxed ignition curves to provide more power to FISCO or FNICO field devices The FNICO method is allowed to be used ONLY in Division 2/Zone 2 applications, and doesn t t account for faults as FISCO does.
H1 Controller Non-hazardous Area UPS 120VAC FNICO Repeater Isolators Hazardous area Class I, Division 2/ Zone 2, Gas Group A& B B with approved Field Devices Redundant Bulk DC Supplies Spur Blocks, Terminators, and FISCO or FNICO Field Devices
Protect critical components of segment H1 card and DC bulk supplies Power conditioners Susceptible spurs (long cable runs or with exposure to the elements) at the spur blocks Transmitters and Positioners with exposure risk
Protection for Trunk and critical Spurs Protection for Field devices Has no affect on communications Must be certified for Area Classification
120 vac SAFE AREA Power Conditioner 10 11 12. MTL5995 SAFE AREA Spur Block