Manual Sor

T21 Thermal Differential Point Switch
General Instructions
The T21 Point Level Switch is a state-of-the-art in liquid level and interface measurement and control. Level detection is accomplished by using a high-resolution thermal differential technique. The sensor wetted parts are of durable 316L series stainless steel, all-welded construction and contain no moving parts. The switch is easy toinstall and adjustable providing reliable, low-maintenance performance in the most demanding applications.

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
Design and specifications are subject to changewithout notice. For latest revision, go to www.sorinc.com Installation Mechanical ................................ 2-3 Electrical .....................................4 Set up and Operation ...........................5 Calibration for Level Switches ............. 6-7 Calibration for Flow Switches.............. 8-9 Dimensions .................................... 10 Cleaning........................................ 11 Troubleshooting ........................... 11-12
Registered Quality System to ISO 9001:2008

Form 1024 (1.10) ©2010 SOR Inc.

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Mechanical Installation
The T21 has a 3/4-inch MNPT mount (standard), designed for easy installation through a threaded port. Conduit is recommended for all wiring to the switch. Due to the pipe thread mounting, it may be necessary to make a trialfit, add or remove teflon tape or other pipe thread sealant and reinstall to achieve a satisfactory seal with the sensor properly oriented. Proper orientation is marked on the switch body for reference. It is generally recommended that the sensor tips be located at 1/4 of the pipe’s ) inside diameter (I.D.) assuming pipe is full. (See Level Application The switch body MUST be oriented with the twosensor tips aligned paralled to the level being detected. (Disregard for top mount installation.)
Tips Sensor Tips Sensor

Tips

Material Direction

Incorrect

Flow Application The swtich body MUST be oriented with the two sensor tips aligned perpendicular to the flow being detected.
Tips

Material Direction

Sensor

Sensor Tips

For level and flow applications the material you are monitoringMUST contact the two sensor tips at the same time .

Use a 1-1/8”, open-end wrench to tighten at the HEX flats of the MNPT of a standard switch. Do not use the instrument head to tighten the switch to the mounting port. Rotation of the instrument head with respect to the sensor body may cause internal wiring damage.

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Form 1024 (1.10) ©2010 SOR Inc.

Tips

Incorrect

Material Direction

SensorSensor

Thread Engagement Pipe Nozzle/ Coupling Length

*Sensor Length
Pipe Wall Thickness 1/4 of p pe I.D. (preferred pip pipe insertion a assuming pipe is full)

Flow

Unit can be mounted above or below pipe. Mounting on top of pipe is displayed above. Nozzle/Coupling length *Sensor Length = + Pipe wall thickness + 25% of pipe I.D. - Thread engagement
Form 1024 (1.10) ©2010 SOR Inc.

3/12Electrical Installation
Remove the instrument enclosure lid by unscrewing in a counterclockwise direction. Loosen the two, board-retaining captured screws. Remove the printed circuit board by grasping the transformer on the center of the board and, while rocking gently back and forth, pull firmly outward. Connect power and alarm relay wiring to Terminal Block TBB as shown in . Reinstall the switchelectronics and tighten the retention screws.

NOTE: Connections to sensors are factory installed and should not be disconnected in the field. NOTE: For 24 VDC operation (factory prepared), connect +24 VDC to TBB7 and 24 VDC return to TBB8. For 115 VAC or 230 VAC operation, there is no polarity. NOTE: Connect ground wire to the ground screw located in back of instrument enclosure. A ground wire...