20
16-
03
18
Z-System – Zener Barriers
Installation
Connecting Circuits
1. Ground the device. Use the integrated ground connection of the zener barrier
for grounding.
The conductor cross-section of the ground connection, using a copper
conductor, must be at least 4 mm
²
(12 AWG).
2. Connect the field circuit.
3. Connect the control circuit.
3.3.1
Grounding with Zener Barriers
Intrinsically safe circuits with zener barriers without galvanic isolation must be
grounded. Observe the grounding requirements according to IEC/EN 60079–14
and NEC 504-50. The maintenance of these requirements prevents the
occurrence of a dangerous potential with respect to ground.
If the zener barrier is not grounded and a fault occurs a dangerous spark can
cause.
Figure 3.3
Non-grounded zener barrier
Note!
For more information on grounding see chapter 3.3.1.
Note!
For more information see the corresponding datasheets.
Zone 0, 1, 2
Div. 1, 2
Fault
Transformer
Power supply
AC/DC
supply
voltage
Haz
ar
dous potential
Haz
ar
dous potential