Endress+Hauser Liquiphant FTL33 Bedienungsanleitung Seite 55

Liquiphant FTL33
6 Electrical connection
The device has two operating modes: maximum safety (MAX) and minimum safety (MIN). 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.
• Maximum safety (MAX)
The device keeps the electronic switch closed as long as the liquid level is below the fork.
Sample application: overfill prevention
• Minimum safety (MIN)
The device keeps the electronic switch closed as long as the fork is immersed in liquid.
Sample application: Dry running protection for pumps
The electronic switch opens if the limit is reached, if a fault occurs or the power fails
(quiescent current principle).
6.1 Connecting the device
In accordance with IEC/EN61010 a separate circuit breaker must be provided for the
device .
6.1.1 Electronic version 3-wire DC-PNP
Voltage source: non-hazardous contact voltage or Class 2 circuit (North America)
M12 connector
Depending on the analysis of the switch outputs, the device works in MAX oder MIN mode.
Electrical connection
M12 connector
Yellow LED (ye) not lit
Yellow LED (ye) lit
K external load
Endress+Hauser
2
3
K
A0022901
Operating mode
MAX
1
4
0.5A
L– L+
A0022858
1 2
1 2
A0021416
Electrical connection
MIN
2 1
4
3
0.5A
K
L+
L–
A0022859
1 4
1 4
A0021417
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