Electrical Connection; Connecting The Measuring Device - Endress+Hauser FTW33 Betriebsanleitung

Liquipoint FTW33
6

Electrical connection

The measuring device has two modes of operation:
• Maximum point level detection (MAX): e.g. as overfill protection
The device keeps the electrical switch closed as long as the sensor is not yet covered by
liquid.
• Minimum point level detection (MIN): e.g. to protect pumps from dry running
The device keeps the electrical switch closed as long as the sensor is covered by liquid.
By choosing the corresponding operating mode, the user ensures that the device also switches
in a safety-oriented manner even in an alarm condition, e.g. if the power supply line is
disconnected. The electronic switch opens if the point level is reached, if a fault occurs or of
the power fails (quiescent current principle).
6.1

Connecting the measuring device

• Supply voltage 10 to 30 V DC
• In accordance with IEC/EN61010 a suitable circuit breaker must be provided for the
measuring device.
6.1.1 M12 connector
Voltage source: non-hazardous contact voltage or Class 2 circuit (North America). The device
must be operated with a fine-wire fuse 500 mA (slow-blow).
Depending on the analysis of the switch outputs, the measuring device works in either MAX
oder MIN mode.
Electrical connection
M12 connector
Symbols Description
Yellow LED (ye) lit
Yellow LED (ye) not lit
K external load
Endress+Hauser
Mode of operation
MAX
2 1
3
4
K
0.5A
L– L+
1 2
1 2
2
3
K
L–
1
1
A0021416
Electrical connection
MIN
1
4
0.5A
L+
4
4
A0021417
33