Eaton F300 megablock range MTL fieldbus device couplers

OVERVIEW

F300 Megablocks are DIN-rail mounted, device couplers for Foundation™ fieldbus 

or Profibus PA networks. They allow connection of field devices to the segment 

trunk cable and provide short-circuit protection to the segment.

Megablocks minimize hand wiring and allow individual devices to be added to 

and removed from the segment without disrupting network communication.

Megablocks are available in four, eight, and twelve port versions. Multiple 

Megablocks are easily wired together to allow larger segments to be constructed.

Each F300 Megablock includes an F97 Terminator for installation in the trunk 

terminals, which is clearly marked with a large ‘T’ for easy identification by field 

personnel.

Individual surge-protector modules (FS32) can also be fitted to any of the 

Megablock fieldbus terminals to provide protection against induced surges and 

transients that can potentially destroy or degrade certain components inside the 

F300 Megablocks.

DESCRIPTION

Simple and reliable interconnection

Each Megablock has dedicated connections for the fieldbus “home run” or trunk 

cable. Trunk connections are identified by their black connectors. Numbered 

(grey) connectors are provided for each spur.

Wiring connections to the Megablock are made using pluggable connectors 

(screw terminal type are standard, but other connection styles are available). 

These allow wire terminations to be made to the individual connectors, which are 

then plugged into the Megablock.  Devices can be connected and disconnected 

easily during commissioning. On completion, the connector retaining screws are 

tightened to secure each connector to the Megablock

MECHANICAL

Mounting orientation

Megablocks mount vertically or horizontally on 35mm DIN rail within a field junction 

box  The use of DIN rail end stops are recommended to prevent sliding (especially for 

vertical installations).

Eight, and twelve port Megablocks have areas on their body for labelling so that 

segments can be easily identified according to plant standards.

Enclosure requirements

General requirements

Megablocks may be mounted in hazardous (classified) areas – see section 8.  The 

following conditions must also be satisfied to ensure safe and reliable operation.

a) Prevent any form of pollution that could compromise the operation of the unit. 

For example, choose an unpolluted location or a suitable enclosure to protect the 

assembly.

b) Provide an adequate level of mechanical protection. This can be achieved by 

selecting a protected location, a suitable enclosure, or a combination of both.

c) Ensure that all cable entries and connections are secure by making provision for 

the careful routing and securing of all cables.

d) Provide adequate security against unauthorized interference.

e) Conform to the permitted ambient temperature range of –45°C to +70°C.

Outdoor mounting

In addition to the General Requirements above, if the Megablock is mounted in an 

outdoor location, use a suitable enclosure with a minimum of IP54 ingress protection.  

A higher level of ingress protection rating will be necessary if the working atmosphere 

is, or can be, corrosive, or if the enclosure is subject to wet or dusty environments.

DIN-rail mounting

The Megablocks are designed for mounting on 35mm x 7.5mm T-section “top hat” DIN 

rail to EN50022 and use built-in DIN rail clips to attach to the rail.  

Mounting procedure

Megablocks are attached to the DIN rail using a “push-and-tilt” method - as illustrated 

on the body label and in Figure 4.1 below.

Tilt the Megablock towards the trunk-connector side of the Megablock and then 

engage the DIN-rail clips under the ledge of the DIN rail. Push the Megablock against 

the edge of the rail then rotate the Megablock until it sits flat onto the DIN rail, then 

release the pressure to allow the clips on the other side to engage.