
Powered Liquid Level Switches
LZ12, LU10, LP15 & LO10 Series Manual
Flowline, Inc. | 10500 Humbolt Street, Los Alamitos, CA 90720 p 562.598.3015 f 562.431.8507 w flowline.com MN301370 Rev B1 1 of 19

Introduction / Table of Contents Step One
ABOUT SWITCH-TEK™ POWERED LEVEL SWITCHES
This manual contains information on all four models of Flowline Switch-Tek™ powered level switches; Vibration
(LZ12 series), Ultrasonic (LU10 series), Optic Leak (LO10 series) and SuperGuard Capacitance (LP15 series).
The switches all feature two outputs: 1) a 4 or 20 mA current switch and 2) a 60VA SPST dry contact relay. All
four series are manufactured with thermoplastics, including the cable, making them submersible in design and
ideal for corrosive applications. Package the switches with either Flowline controllers (LC10 or LC40 series) or
interface directly to another controller or PLC.
TABLE OF CONTENTS
Specifications: ................................................................................................................ 3
Sensor Information: ........................................................................................................ 4
Vibration Level Switch (LZ12 Series): ................................................................. 4
Maintenance Alarm: .................................................................................. 5
Ultrasonic Level Switch (LU10 Series): ............................................................... 6
Optic Leak Detection Switch (LO10 Series): ....................................................... 7
Capacitance Level Switch (LP15 Series): ............................................................ 8
Safety Precautions: ........................................................................................................ 9
Make a Fail-Safe System:: .................................................................................. 9
Installation: ................................................................................................................... 10
Through Wall Installation: .................................................................................. 10
Top Wall Installation: ......................................................................................... 10
Electrical: ...................................................................................................................... 11
Wiring: .......................................................................................................................... 12
Wiring to a Flowline Controller: ..................................................................................... 12
Switching Inductive Loads: ................................................................................ 12
Wiring the Relay Output: ................................................................................... 13
Intrinsically Safe Control Drawings (LU10 Series Only): ...............................14-15
Wiring as a P-Channel or N-Channel Output: .................................................... 16
Maintenance: ............................................................................................................... 17
Cleaning Procedure: ......................................................................................... 17
LZ12 Maintenance Alarm: ................................................................................. 17
Testing the Installation: ..................................................................................... 18
Warranty, Returns & Limitations: .................................................................................. 19
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Specifications - Common Step Two
Orientation: Universal
Accuracy: ± 1 mm in water
Repeatability: ± 0.5 mm in water
Supply voltage: 12-36 VDC
12-30 VDC (LZ12 Only)
Consumption: 25 mA maximum
Contact type: (1) SPST relay
Contact rating: 60VA (125 VAC max / 1A
max)
Contact output: Selectable NO/NC
Process temp.: F: -40° to 176°
C: -40° to 80°
Pressure: 150 psi (10 bar) @ 25 °C.,
derated @ 1.667 psi (.113 bar)
per °C. above 25° C.
Sensor rating: NEMA 6 (IP68)
NEMA 4X (IP65) - LU10-2_ _5
series only
Cable type: 4-conductor, #22 AWG
(shielded)
Cable length: 10' (3m) - Standard
25' (7.6m) or 50' (15.2m) -
Special
Process mount: 3/4" NPT (3/4" G / R)
Mount. gasket: Viton® (G / R version only)
Classification: General purpose
CE compliance: EN 61326 EMC / EN 61010-1
safety
COMMON SPECIFICATIONS
MN301370 Rev B1 3 |

Sensor Information - Vibration Step Three
Sensor material: Ryton® (glass fill)
Viton® cable grommet
Process temp.: F: -40° to 176°
C: -40° to 80°
Maint. alarm: NPN transistor, 10 mA max.
Cable jacket mat’l: PP
Cable type: 5-conductor, #24 AWG
(shielded)
VIBRATION LEVEL SWITCH (LZ12 SERIES)
The Vibration switch operates at a nominal frequency of 400 Hz. As the switch becomes immersed in a liquid
or slurry, a corresponding frequency shift occurs. When the measured frequency shift reaches the set point
value, the switch changes state indicating the presence of a liquid or slurry medium. For optimum performance
and proactive maintenance, the sensor automatically adjusts for coating, and if necessary, outputs a
preventative maintenance alarm.
Do not squeeze the forks together. Doing so could damage or break the sensor and void the warranty.
When powering up the LZ12, the start-up procedure requires the switch to cycle through a wet condition for 1/2
second in order to determine an initial resonance.
LZ12 SPECIFICATIONS
CONFIGURATIONS
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Sensor Information - Vibration Step Three
Sensor Power
[RED & BLK wires] / 36 VDC Max.
5 ±1mA Dry / 22 ±1mA Wet
Relay Rating
[GRN & WHT wires] / 60 VA
Maintenance Alarm
[YEL wire] / NPN Transistor / 10mA Max.
To wire the maintenance output wire to a PLC, follow the wiring diagram below. The Yellow wire is connected
to the PLC input with a 10 kΩ resistor parallel to the PLC input and the (+) of the power supply.
Sensor Power
[RED & BLK wires] / 36 VDC Max.
5 ±1mA Dry / 22 ±1mA Wet
Relay Rating
[GRN & WHT wires] / 60 VA
Maintenance Alarm
[YEL wire] / NPN Transistor / 10mA Max.
MAINTENANCE ALARM (LZ12 VIBRATION ONLY)
For optimum performance and proactive maintenance, the sensor automatically adjusts for coating, and if
necessary, outputs a preventative maintenance alarm. The Yellow wire is a NPN transistor designed to switch
when a build-up of material prevents the vibration switch from operating at its operational frequency. Use the
Yellow wire to identify when the Vibration switch requires cleaning. To wire the maintenance output wire to an
LED, follow the wiring diagram below. The Yellow wire is connected to the LED and a 2.2kΩ resistor in series
and referenced back to the (+) of the power supply.
MN301370 Rev B1 5 |

Sensor Information - Ultrasonic Step Three
Sensor material: 1_ _5: PP
2_ _5: PFA
Classification: Intrinsically safe
Approvals: CSA: Class I, Groups A,
B, C & D; Class II, Groups
E, F and G; Class III
EEx: Class 1, Division 1,
Groups A, B, C, D; EEx ib
IIC T6
Cable jacket mat’l: 1_ _5: PP
2_ _5: PFA
Parameters: CSA: Vmax = 32V, Imax = 300
mA, Pmax = 1.3 W; Ci = 0 µF, Li
= 0 µH
EEx: Ui = 32V; Ii = 300 mA; Pi =
1.3 W; Ci = 0 µF; Li = 0 µH
Certificates: CSA: LR 79326
EEx: LCIE 01.E6048 X
ULTRASONIC LEVEL SWITCH (LU10 SERIES)
The Ultrasonic switch generates a 1.5 MHz ultrasonic wave from a miniature piezoelectric transducer located
on one side of the gap within it’s sensing tip. Another piezo transducer, located on the other side of the gap,
acts as a microphone, picking up the sound wave. When liquid enters the gap, there is a change in the speed
the wave crosses the gap. This change in the speed of sound identifies whether the sensor is in liquid or in air.
The sensor should be installed so that the liquid will drip out of the gap when the sensor becomes dry.
LU10 SPECIFICATIONS
CONFIGURATIONS
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