Electrical Connection; Connecting The Measuring Device - Endress+Hauser Liquipoint FTW23 Bedienungsanleitung

Liquipoint FTW23
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.
• 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 connection 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
Function monitoring
With two-channel evaluation, functional monitoring of the sensor is also possible in addition
to level monitoring.
Endress+Hauser
Mode of operation
MAX
1
2
3
4
K
0.5A
L– L+
1 2
1 2
Electrical connection
MIN
2 1
4
3
0.5A
K
L+
L–
1 4
1 4
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