User guide

ManualsBrandsSOR ManualsSensorsSingle Point Ultrasonic Level Switch

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

Summary of content (16 pages)

PAGE 1
Ultrasonic Point Level Switches General Instructions 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.
PAGE 2
PC Board Arrangement Models beginning with 71 Failsafe Slide Switch 9-Position Terminal Block (Reverse Side)  Ground (Earth)  Power Supply  DPDT Level Indication Relay Contact Factory-sealed sensitivity pot No adjustment required Replacable Fuse(s) Liquid Level Indication LED Sensor Lead Connection J1 (remote cable connection A) Sensor Lead Connection J2 (remote cable connection T) Models beginning with 72 Sensor Monitor LED 6-Position Terminal Block (Reverse Side)  DPDT Sensor Monitor Relay Contac
PAGE 3
Sensor Installation Notch-Type Sensor (Series 37  - N) Series 370 Ultrasonic Level Sensors can be mounted by inserting the sensor through a fitting in a vessel, or the sensor may be suspended over an open sump or basin. DO NOT weld any part of this instrument. Irreparable damage may be done to Teflon sensors by turning Metal hex and Teflon hex separately. Always rotate Metal hex and Teflon hex simultaneously. Do not apply more than 10 in. lbs.
PAGE 4
Alignment mark shown at 3 o’clock Alternate position: 9 o’clock 1 inch minimum Open Sump or Basin Do not suspend the unit by rigid conduit installed in the electrical hub. When installing the unit over an open sump or basin, use a suitable bracket to support the instrument.
PAGE 5
Viscous Sensor Cavity Orientation Bottom View Viscous Sensor with 4-Hole Flange ø 76.2 minimum 3.00 opening required (typ.) 5.9 0.23 5.9 0.23 CL of flange 62.1 2.44 (typ.) Alignment mark (other side) position at 6 o’clock (typ.) Bottom View Viscous Sensor with 8-Hole Flange Electrical Connection Electrical power must be disconnected from explosion proof models before the cover is removed. Failure to do so could result in severe personal injury or substantial property damage.
PAGE 6
Nine-Position Liquid Level Relay Terminal Strip GND 24VDC NC1 C1 NO1 NO2 C2 NC2 + - NC1 C1 NO1 NO2 C2 NC2 L1 N GND 120 VAC NC1 C1 NO1 NO2 C2 NC2 L1 L2 GND 240VAC C A B Sensor Condition Liquid Level Relay Contact A Continuity Chart Relay Continuity Chart Fail-safe Mode Switch Position Relay energized on high level Relay energized on low level Liquid above sensor NC1 C1 NO1 NO2 C2 NC2 Relay Energized Liquid below sensor NC1 C1 NO1 NO2 C2 NC2 Relay De-engergized Liquid abo
PAGE 7
One Point Remote Cable Connection - Models 711R1 and 721R2 Only Install conduit between the sensor base and the electronics housing to provide a raceway ) The sensor base and the electronics housing are for sensor extension cables. (See suitable for use in Class I Groups C & D; Class II Groups E, F & G; Divisions 1 & 2 hazardous locations. All conduit and fittings used for the installation must equal or exceed this rating to maintain the explosion proof integrity of the assembly.
PAGE 8
Discharge the Sensor Temperature changes which occur during shipment may result in a small electrical charge inside the sensor crystals. This charge is harmless to humans, but may result Short each in damage to the electronics if the center conductor to the shell to discharge sensor is plugged in before it is sensor crystals. discharged. To discharge the sensor, touch a wire to each sensor connector so that the center conductor and outside shell make contact.
PAGE 9
Fishing the Sensor Extension Cables Three sensor extension cables are supplied. Both ends of the cables are terminated and labeled at the factory. Protect factory installed plugs Use care to avoid damaging the factory installed coax connectors while fishing the sensor extension cables through the conduit. Pull cables from the sensor base so that the free ends follow the fish through the conduit. ) Leave enough cable (See in the electronics housing to make PC board connections.
PAGE 10
Plug in Connections Inside Electronics Housing Discharge the sensor per instructions on page 8. Attach the PC board connectors according to Figure . Note that cable T can be connected to J2 on either the upper or the lower PC Board. J1 Plug in sensor lead A J2 Plug in sensor lead T PC Board Labeled UPPER J1 Plug in sensor lead B J2 Alternate Connection for sensor lead T PC Board Labeled LOWER Electrical power must be disconnected from explosion proof models before the cover is removed.
PAGE 11
Pump Logic Accessory — Models with PL near the end of the Model Number Two point ultrasonic level switches with the PL accessory are supplied with a third PC board that has a DPDT relay for pump logic control. This third board is factory wired to one set of liquid level relay contacts on each sensor cavity PC board.
PAGE 12
 Reinstall the two screws to secure the PC board bracket to the housing.  Go to C. Two Point Sensors (712 or 722) Upper and lower sensor cavities are connected to dedicated PC Boards. The PC boards are marked Upper and Lower to indicate which board belongs to which sensor. One or both of the boards can be replaced. To replace the Upper board:  Unscrew the three 1-1/2” #4 mounting screws which fasten the Upper board to the housing mounting bracket. (Note spacer locations.) Unplug sensor cable A.
PAGE 13
Sensor Test Procedure  Disconnect a sensor cable from the PC board. Measure the capacitance across the pin and shell of the male mini phono connector.  Capacitance from 600 to 1500pf indicates circuit is good. Plug the sensor cable back into the PC board. Go to step 2. See note below for epoxy sensor capacitance values.  Capacitance lower than 600pf or higher than l500pf indicates that the circuit is bad. For remote units, go to Step 1a. Otherwise, go to Step 3. a.
PAGE 14
Model No. of 1 pt control for metal notch integral sensor Replacement Board includes hardware Model No. of 1 pt control for metal notch remote sensor Replacement Board includes hardware Model No.
PAGE 16
Control Drawing Printed in USA sorinc.com 14685 West 105th Street, Lenexa, KS 66215  913-888-2630  800-676-6794 USA  Fax 913-888-0767 16/16 Registered Quality System to ISO 9001 Form 829 (08.13) ©SOR Inc.