KROHNE ALTOFLUX IFM4042K EEx EN - Manual (Page 7)

6
•
The current output (terminals I, I
⊥
) and the additional power supply (terminals 1L=, 0L=)
must be galvanically separated connected and driven from each other. To avoid voltage or
current summation, at least one of the two circuits must be isolated from earth potential. It
is not allowed to drive both circuits at the same time with grounded zener barriers. Both
current circuits, including all connection cables, must be galvanically separated at all times
according to the valid regulations.
•
Also in case of non-intrinsically safe connections, it is absolutely necessary to maintain a
galvanic separation between the current output circuits and the additional power supply
connections. Without a galvanic separation, the IFC 040-EEx signal converter electronics
will be damaged, because these two circuits are internally connected to each other.
•
A safe connection of the IFC 040-EEx signal converter electronics with the equipotential
bonding system is achieved through the zinc-plated mounting frame, which must be
securely screwed to the aluminum signal converter housing (PE potential) by means of
two long-shafted screws. To access the two long-shafted screws it is necessary to
unscrew the display unit and fold it aside. The screws must be tightly secured with a
torque of 1.3 Nm (a 2 Pt. Phillips screwdriver is recommended).
2.2 Safety-technical data
The safety-technical data are listed in the table below.
Important: The functional-technical must also be regarded, therefore see the standard
installation and operating instructions.
Electrical data (per circuit)
Terminal
designation
Function Type of protection
"EEx ib"
Type of protection
"EEx e"
Circuit 1
I, I
⊥
Current output, passive
(2-wire connection)
4-20 mA, HART = possible
U
n
= 14…36 Vdc
I
n
= 4…20 mA
U
m
= 250 V
Circuit 2
1L=, 0L=
Additional power supply
(4-wire connection)
additional to circuit 1 (optional)
Maximum values:
U
i
= 30 V, I
i
= 100 mA,
P
i
= 1.0 W
C
i
= 20 nF, L
i
= 0
U
m
= 60 V
U
n
= 14…36 Vdc
I
n
= 22 mA
U
m
= 250 V
Circuit 3
B1, B
⊥
B2, B
⊥
Passive pulse/status output 1
Passive pulse/status output 2
Maximum values:
U
i
= 30 V, Ii = 100 mA,
P
i
= 1.0 W
C
i
= 0, L
i
= 0
U
m
= 60 V
Maximum values:
U = 36 V
I
= 100 mA
U
m
= 250 V
Table 4: Safety-technical data of output circuits.
2.3 Connection examples
In this section two examples for connection of the IFM 4042 K-EEx compact flowmeter are
described for operation in the 2-wire mode (figure 2) as well as in the 2x2-wire mode (figure
3).
See figure 2 on the next page. It shows an IFM 4042 K-EEx with the terminal compartment in
version A (EEx de [ib] with U
m
= 60 V). The flowmeter is connected through a so-called
transmitter power supply ("EEx i" approved) in 2-wire mode. If data communication with the
flowmeter through the HART protocol is required, the transmitter power supply unit must be
HART compatible. Terminals I, I
⊥
are not polarity sensitive.