Eaton BA484DF-F Fieldbus intrinsically safe display

F300 Megablocks are DIN-rail mounted passive hubs for Foundation™

fieldbus H1 and Profibus PA networks for general purpose, Zone 2 and

Division 2 applications. They provide a simple means of connecting field

devices to the network trunk cable, and protect the segment from spur

short circuits. Megablocks minimize hand wiring and allow individual

devices to be added to and removed from the segment without

disrupting network communication. A green power LED on each unit

indicates whether at least 10V dc is present. F300 Megablocks are

available in four, eight, and twelve drop versions.

The black Trunk In/Out pluggable connector allows replacement of

a Megablock without breaking the trunk connection to other devices

on the fieldbus segment. The F97 terminator supplied should be

mounted in the Trunk-out connection to provide termination when the

Megablock is located at the end of the fieldbus segment; alternatively,

if the segment is extended, it can be removed to ensure the correct

termination is maintained.

Spur connections to the Megablock are made using pluggable, grey,

screw-terminal or spring clamp terminal connectors. Wire terminations

can be made to the individual connectors before plugging them into

the Megablock. Devices can then be connected and disconnected

easily during commissioning. After commissioning, retaining screws

are tightened to secure each connector to the Megablock. Separate

numbered connections are provided for each spur drop.

SpurGuard™ is a device-port, short circuit protection technique

that minimizes susceptibility to single points of failure. The F300

Megablock has built-in SpurGuard™ protectors that prevent a short

circuit in any of the individual field devices or spur cable runs, from

bringing down the entire fieldbus segment. A red LED near each

spur connection indicates when a spur is shorted and hence in “over

current” mode.

The optional FS32 modules can provide surge protection for the

F300 products on both the trunk and spur terminals. These pluggable

modules are simple to fit in a new installation, or as a retrofit option.

A range of MTL Process Junction Boxes in stainless steel and carbon

loaded, glass-reinforced polyester are available for mounting Megablock

wiring components. They offer plenty of space for termination and

wiring, making it easy to install and maintain the fieldbus system.

F300 Megablock hazardous area approvals permit

installation in a variety of configurations in Zone 2 and Division 2

hazardous areas. Typically, F300 Megablocks may be installed with

non-sparking (non-arcing) trunk and spur connections. Alternatively,

when connected to suitably certified fieldbus power supplies, the trunk

may be non-sparking (non-arcing) with non-incendive or intrinsically

safe Ex ic spur connections.

When installed on a non-sparking trunk with Ex ic spurs, an

F300-A01 trunk-spur partition must be installed on the F300 Megablock.

The trunk-spur partition is supplied as a pack of 5. as detailed in the

Accessories section of this document.