MTL7000 SERIES
Shunt-diode Safety Barriers

Ultra-slim Safety Barriers that can be used like terminals

• Exceptionally high packing densities - only 7mm barrier width
• Quickly and easily installed clamp securely onto DIN rail in one simple operation
• Commissioning and maintenance simplified - secondary replaceable fuse (MTL7100 barriers) and removable link (MTL7200 barriers) provide 'disconnect' features
• 24V dc supply connections simplified- optional power comb feeds many barriers
• Direct connection of cable screens and OV lines - third terminal on both hazardous and safe side
• Reduce need for separate field terminals - many features common to conventional terminals

MTL7000 Series award-winning, intrinsically safe shunt-diode safety barriers are innovative devices designed to provide exceptionally high packing densities, straightforward 'single-operation' installation and simplified connection, commissioning and maintenance facilities. Many of the MTL7000 Series' features duplicate the functions of conventional field terminals and the barriers con, therefore, 'double up' as terminals for many applications, saving even more space.

A barrier width of only 7mm enables maximum packing densities due to the use of surface mount and thick-film hybrid circuit technologies (subjects of patent applications).

Barriers clamp simply and securely onto standard T-section DIN rail, simultaneously making a reliable IS earth connection. Earth terminals, insulating spacers and corrosion-resistant DIN rail are available to satisfy individual IS earthing requirements.

Extra terminals on each side of the barrier allow cable screens from field wiring and OV returns to be terminated on the barrier. 'Dummy barriers handle spare hazardous-area cable screens and signal lines. Additionally, and as an alternative, an earth rail accessory is available for terminating and securing cable screens, or earth returns and spare cores.

Barrier identification is provided by one or both of two methods. The first consists of tagging strips mounted on posts located at each end of a row of barriers while the other consists of separate identifiers attached to the tops of individual barriers. Of these, the first can be used to tag locations as well as barriers and is recommended for large installations while the second is better suited to installations of a few barriers only.

An optional power comb simplifies installations where multiple barriers are powered from a common 24V dc source (a power feed module or a dummy barrier). The comb replaces individual power supply connections to each barrier, yet allows single barriers to be removed without affecting the others. The power feed module powers up to 40 barriers and incorporates a trip which switches oft the supply to the barriers if a fault (such as an overvoltage) occurs in the power source circuit.

Secondary replaceable fuse versions of many barriers are available and form the MTL7100 sub-series. These ore useful where there is a possibility of faults occurring during commissioning which would otherwise blow the barriers' internal safety fuses. One secondary replaceable fuse for each barrier channel is provided and is lower in value than the related safety fuse. Fuses are packaged in small mouldings which con be latched in a 'disconnect' position to break the safe and hazardous areas during commissioning, maintenance or fault finding, thus avoiding the need for additional disconnect terminals.

Where a fuse is less likely to be necessary, the MTL7200 sub-series uses a latching-out link only, to provide the basic loop disconnection of the MTL7100 sub-series.

Data Sheet