KROHNE CORIMASS E P MFM 2081 EEx EN - Manual (Page 7)

Additional Instruction for Ex version MFM 2081 / 3081 7
• The PE protective ground conductor must be connected to the separate U-clamp
terminal in the terminal box of the signal converter.
•
Do not cross or loop the cables in the terminal box of the signal converter. Use
separate (PG or NPT) cable glands for power and output cables.
•
Ensure that the screw thread of the round cover on the terminal box is well greased at
all times.
NOTE: The grease used must be non-corrosive to aluminium; it must be resin- and acid-
free.
•
Protect sealing ring from damage.
5 6 4 4.1 4.2 11 12
N L AC
Output- - + DC
Connection PE
s. table
Fig. 2: Power and signal connections for MFC 081 K/F without intrinsically safe outputs
The tables below show the possible input output connection for the converter. The exact
configuration depends on which optional output modules were fitted in the factory.
Table of input/output connections
Nr. Option 1 (Current, pulse, alarm
and input)
Option 2* (2x current, not
galvanically isolated)
5 Common (-) Common (-)
6 Current output (+) Current output 1 (+)
4 Control input Control input
4.1 Pulse output Current output 2 (+)
4.2 Status output (active) Status output (passive)
* The inputs/outputs share a common signal ground which is galvanically isolated from the
ground (PE)
In addition, the signal may need protection from external interferences. The use of screened
cables and a filter capacitor next to any counter is recommended (Fig. 3).
It is possible to connect the pulse output without an external voltage supply. However to do
this the function of the status output must be sacrificed. (Fig. 4)
If the alarm output is used to power the pulse signal then the following settings must be
made in the menus:
(i) Fct. 3.5.1 ALARM FUNCTION must be set to OFF.
(ii) Fct. 3.5.2 ALARM ACTIVE LEVEL must be set to ACTIVE LOW.