6
INM9120 Rev 8
2 .3 .2
Host and IS fieldbus connections
The block diagram (Figure 7) shows terminals 5 and 8 marked with an ‘S’. This indicates a termination
point for the fieldbus cable screen. These are termination points only, with no internal connection
.
2 .3 .3
Power connection
The 912X-IS units can accommodate two power inputs for applications that require redundancy.Internal
steering diodes ensure correct power sharing.
Connect supplies as indicated below
2 .4 MAKING CONNECTIONS
2 .4 .1
Screw clamp connector
(a) Strip back the insulation of conductors (7mm - recommended strip length - See note).
(b) Check the terminal assignments, as indicated on the side label of the unit.
(c) Insert conductor into connector and tighten screws
.
2 .4 .2
Spring (cage) clamp connector
(a) Strip back the insulation of conductors (10 mm - recommended strip length - See note).
(b) Check the terminal assignments, as indicated on the side label of the unit.
(c) Press screwdriver blade into groove on spring clamp; fully insertconductor; remove screwdriver.
Note if the wires are to be fitted with crimp ferrules consult ferrule manufacturer’s recommendation
2 .5 FINISHING .
Wire up individual FISCO power supplies in accordance with wiring schedules. Power supply connections
can be onward linked from one power plug to the next (i.e. ‘daisy-chained’).
Segregate intrinsically safe wiring from other wiring into separatetrunking or looms wherever possible
to avoid errors and maintain a
tidy installation.
Figure 7 - Power supply block diagram
+ ve to
terminal
- ve to
terminal
Single power input
Power 1 1 or 3 2
Redundant power
Power 1 1 2
Power 2 3 2
