3scort TD-150 User Manual page 55

Wiring with fuse (FU1) or resistance (R1)
The sensors are shipped with kits that contain 2 ballasts/resistances. Each of them can be
installed instead of the fuse from kit (not along with it) in case it is necessary to comply with
special anti-explosion safety requirements.
The black resistance must be used if the sensor is to be powered up by a 12 V power
supply. The red one must be used if the 24-36 V power supply will be used.
The idea behind this is that, if there is a short circuit or a sudden voltage surge in the
connection with the power supply, the resistance - installed outside the immediate danger
zone - will burn and thus disrupt the chain before any sparks will have time to reach the sensor
installed in the explosive zone and provoke an explosion.
Fig. 67
Fuse and resistor
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