13
7. Electrical connections
7.1 Basic information
A typical intrinsically safe connection for the Level Plus
®
SoClean
®
trans-
mitter includes protective safety barriers, a power supply and a reading
or monitoring device. Refer to Agency information in Section 12.
7.2 Safety recommendations
Be sure to:
1. Always follow applicable local and national electrical codes and
observe polarity when making electrical connections.
2. Never make electrical connections to the SoClean
®
transmitter
with power turned on.
3. Make sure that no wire strands are loose or sticking out of the
terminal block connection which could short and cause a
problem.
4. Make sure that no wire strands, including shield, are in contact
with the electronic module enclosure.
5. The electronics module enclosure is grounded through internal
circuitry and is electronically isolated from the explosion-proof
housing.
7.3 Industrial topologies
There are four topologies described and illustrated below. However, the
daisy chain topology is not recommended by MTS.
Point-to-point
The point-to-point topology consists of having only one device on the
loop as shown in Figure 8. This topology is not usually used with a bus
network since it does not take advantage of placing multiple devices on a
loop.
PLC
Level Plus
®
SoClean
®
Operation Manual
Fig. 6: Threaded flange mounting for flexible pipe
Fig. 7: Tri-Clamp mounting for pipe
Fig. 8: Point-to-point topology
Bus with spurs
The bus with spurs topology has a main trunk cable that has each device
connected via its own spur at a junction box as shown in Figure 9. The
bus with spurs and tree topologies can also be used together to form a
hybrid topology.
Tree alignment
The tree topology is very similar to the bus with spurs topology with the
main difference of having a common junction box for all of the transmit-
ters as shown in Figure 10. Bus with spurs and tree topologies can also
be used together to form a hybrid topology.
Daisy chain
The daisy-chain topology utilizes a single cable that is connected to all of
the transmitters with the cable being interconnected at each field device.
When using this topology make sure that the wiring practice allows for
one transmitter to be disconnected without disconnecting the entire loop
as shown in Figure 11. MTS does not suggest using the daisy-chain
topology.
PLC
PLC
Fig. 9: Bus with spurs topology
Fig. 10: Tree topology
Fig. 11: Daisy-chain topology
PLC
