SOR Single Point Ultrasonic Level Switch - Manual

Form 829 (08.13) ©SOR Inc. 1/16
The Ultrasonic Point Level Switch indicates liquid presence/absence within a sensor
cavity. Two piezoelectric crystals face each other across the sensor
cavity. One crystal transmits an ultrasonic signal; the other crystal
receives the signal.
When the sensor cavity is empty, the receiver detects a weak signal
because air is a poor conductor of ultrasonic waves. With the failsafe
switch in the “HI” position, the normally open relay contacts remain
open, and the Liquid Level LED is not lit.
When process liquid fills the sensor cavity, the receiver detects a strong
signal because liquids are good conductors of ultrasonic waves. With
the failsafe switch in the “HI” position, the normally open relay contacts
are closed, and the Liquid Level LED is lit.
The Failsafe Slide Switch reverses the relay actuation. However, the
liquid level LED is lit only when the relay is energized.
The sensor monitor circuitry (standard on 721 and 722 series switches
only) constantly monitors sensor integrity and opens the normally open
contacts of the sensor monitor relay in the unlikely event of a sensor failure. The relay is
energized when the sensor is operating properly.
Ultrasonic
Point Level Switches
General Instructions
Registered Quality System to ISO 9001
Design and
specifications are
subject to change
without notice.
For latest revision,
go to sorinc.com
NOTE: If you suspect that a product is defective, contact the factory or the SOR ® Representative
in your area for a return authorization number (RMA). This product should only be installed by
trained and competent personnel.
Table of Contents
PC Board Arrangement ...............................2
Sensor Installation ................................ 3-4
Electrical Connection .................................5
Sensor Monitor Connection .........................6
One Point Remote Cable Connection ........... 7-8
Time Delay Adjustments ........................... 10
Pump Logic Accessory ............................. 11
PC Board Field Replacement ..................... 11
Sensor Test Procedure ............................. 13
Replacement Fuses ................................ 13
Spare Parts .......................................... 13
Troubleshooting ..................................... 14
Control Drawings ............................... 15-16