KROHNE OPTIFLUX 4040 C Ex EN - Manual (Page 10)

3
ELECTRICAL CONNECTIONS
10
OPTIFLUX 4040 C
www.krohne.com 09/2010 - 7312232100 - AD EX OPTIFLUX 4040 C R01 en
3.1 Equipotential bonding system
The flowmeter must be incorporated into the equipotential bonding system through the internal
or external PE-clamp. The external clamp is suitable for wires up to 4 mm
2 cross section.
Disconnection from the equipotential bonding system is only allowed when the flowmeter is not
in contact with power supplies or ground voltages outside the hazardous area.
3.2 Terminal arrangment
To connect external devices to the signal output terminals, the wiring requirements for the type
of protection of the compartment must also be conform to the international or national standard
involved (e.g. EN 60079-14). The terminal arrangment is shown by the following figure.
The following outputs are available for connection to external circuits:
Current output Current output Current output Current output
This circuit constitutes a passive 4...20 mA current loop and includes the HART protocol of the
communication device (choice of polarity free).
Additional power supply or power booster Additional power supply or power booster Additional power supply or power booster Additional power supply or power booster
These terminals are connected to provide the 2x2 wire mode (choice of polarity free).
Binary outputs Binary outputs Binary outputs Binary outputs
Terminals B1 and B
gnd
can be configured as pulse or status output through software.
Terminals B2 and B
gnd
can be configured as pulse or status output to NAMUR.
Galvanical separation of circuits Galvanical separation of circuits Galvanical separation of circuits Galvanical separation of circuits
The internal electrode circuit with type of protection "EEx ib" is galvanically connected to the
aluminum signal converter housing (i.e. PE potential). The current output, the additional power
supply and the internal field current circuit are galvanically connected to each other.
Figure 3-1: Terminals OPTIFLUX 4040 C
1 Current output
2 Binary outputs
3 Power booster (additional power supply)
4 PE (Protective Earth) / FE (Functional Earth)