Tecfluid AMD For 2000 Series - Manual (Page 3)

3
If you don’t have the detector, the operation of the amplifier can be checked using the following
circuit diagram:
MAINTENANCE. Electrical verification of the limit switch
Connect a multimeter with the scale in DC mA, in series with the brown cable.
Verify that the current is more than 2.1 mA when the float goes trough the ring upwards, and less
than 1 mA when the float goes trough the ring downwards.
If you don’t have the NAMUR amplifier, the current can be checked using the following circuit
diagram:
AMD
+
-
1 k 
+
-
Browrn
Blue
Battery 9 V
(Nominal 8 V for
NAMUR )
Multimeter
mA
+
-
TECHNICAL CHARACTERISTICS
The AMD is a NAMUR (DIN 19234) sensor with the following nominal characteristics:
Nominal voltage
8 V
Power supply internal resistance 1 k 
Current with the float below the AMD  1 mA
Current with the float above the AMD  2.1 mA
Power supply limits
5 ... 25 VDC
Ambient Temperature 0 ... +40 ºC
Self inductance ≤120 µH
Self capacity ≤90 nF
Conforms with the Directive EMC 89/336/EEC and ATEX 94/9/CE
Amplifier
+
+
-
-
Multimeter
mA
NAMUR
conection
Potentiometer 20 k 
With the potentiometer we modify the current of the NAMUR amplifier. The switching point must be
between 1.2 mA and 2.1 mA. That is, with the current below 1.2 mA the output relay must have a
state and above 2.1 mA the output relay must have the other state.