BABBITT LS8500 User manual

www.babbittinternational.com Reference Manual
2020 Rev.2
LS8500 Presence/Absence Switch
OWNERS MANUAL
♦INSTALLATION
♦CALIBRATION
♦TROUBLESHOOTING
♦WARRANTY
P.O. Box 70094
Houston, TX 77270
[phone]

www.babbittinternational.com Reference Manual
2020 Rev.2
TABLE OF CONTENTS
Page
1. Description -------------------------------------------------------------------- 1
A. General Description ------------------------------------------------ 1
B. Specifications ------------------------------------------------------1-2
2. Theory of Operation/ Ordering Information ------------------------------ 3
3. Installation ---------------------------------------------------------------------3
A. Inspection ------------------------------------------------------------ 3
B. Physical Installation of Probe ------------------------------------- 3
C. Installing the Receiver ----------------------------------------------4
D. Typical Applications and Wiring Diagrams -------------------5-7
1) LS8000 Terminal Layout --------------------------------5-7
2) Ladder Diagrams ------------------------------------------5-7
4. Calibration -------------------------------------------------------------------- 8
A. Setting the Time Delay -------------------------------------------- 8
B. Fail Safe Selection -------------------------------------------------- 8
C. Sensitivity Calibration --------------------------------------------- 9
5. Maintenance and Troubleshooting ------------------------------------- 9-10
6. Warranty -----------------------------------------------------------------------11

www.babbittinternational.com Reference Manual
2020 Rev.2
Read this manual before working with the product. For personal and system safety, and for optimum product
performance, make sure that you thoroughly understand the contents before installing, using or maintaining this
product.
For equipment service or support needs:
Customer Service: 1-800-835-8012 or 713-467-4438 (8:00 a.m. to 5:00 p.m. CST US)
Failure to follow safe installation and servicing guidelines could result in death or serious injury.
Make sure only qualified personnel perform the installation.
Use the equipment only as specified in this manual. Failure to do so may impair the protection provided by the
equipment.
Do not perform any services other than those contained in this manual unless you are qualified.
Explosions could result in death or serious injury.
Verify the operating environment of the Babbitt LS8500 Presence/Absence switch is consistent with the
appropriate location certifications.
Do not remove the housing cover in explosive atmospheres when the circuit is alive.
To prevent ignition of flammable or combustible atmospheres, disconnect power before servicing.
High voltage that may be present on leads could cause electrical shock.
Make sure the main power to the Babbitt LS8500 Presence/Absence switch is off and the lines to any other external
power source are disconnected or not powered while wiring the instrument.
WARNING
NOTICE

www.babbittinternational.com Reference Manual
2020 Rev.2
LS8500 PRESENCE/ABSENCE SWITCH
1. DESCRIPTION
A. General Description
The LS8500 is a point level switch that detects the presence or absence of material in a pipe. The basic
unit is made up of a solid stainless steel flange attached to an explosion proof housing. Inside the
explosion proof housing is a transmitter that is connected to the receiver board by a twisted, shielded pair
of wires. The receiver board may be mounted up to one mile from the flange. All calibration adjustments
and indicators are at the receiver. The receiver also has the relay output and an on board fuse. The unit is
calibrated in the absence of material and an on board relay at the receiver changes state when material is
detected.
B. Specifications
Electrical
Power: 115 VAC (±15%) 50/60 Hz. 2 watts, standard.
(12 VDC, 24 VDC or 230 VAC optional)
Output: 2 Form C contacts, DPDT relay, 5 amp resistive
at 125, 250 VAC; 30 VDC
Fuse: On board, 250 mA @ 125 volts
Fail Safe: Selectable high or low level
Time Delay: Selectable: ON or OFF delay
Adjustable: 1/8 sec to 2 hrs.
RF Frequency: Approximately 1.3 MHz
Environmental
Hazardous Area: Transmitter: Housing is CSA and UL approved for Class I, Div. 1,
Groups C & D; Class II, Groups E, F & G
Receiver: Open printed circuit board can be put in
enclosure as required by application.
Temperature: Probe: -30° F to 180° F**
Electronics: -40° F to 185° F**
Pressure: Probe: 200 PSI @ 75° F**
(**Higher ranges available upon request)
Construction: Probe: All wetted parts, 316 SS Teflon (or UHWMPE) and Viton.
A Halar coating can be applied to the flange when applicable.
Transmitter: Housed in cast aluminum explosion proof enclosure
Receiver: Printed circuit board mounted on plastic track provided
with each unit.
Specifications subject to change without notice.
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www.babbittinternational.com Reference Manual
2020 Rev.2
C. Ordering Information
LS8500 -115VAC - FP - 4” 150# - PR
Model #
(LS8500)
Power Supply:
(115VAC 24VDC 12VDC 220VAC)
Sensor Type:
(FP-Flange Probe or TC-Tri-Clamp)
Sensor Size:
Flange Model:
(PR-Partial Ring or FR-Full Ring)
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www.babbittinternational.com Reference Manual
2020 Rev.2
2. THEORY OF OPERATION
The LS8500 employs a radio frequency (RF) balanced impedance bridge circuit to detect if the sensing
element is in contact with the material that is to be sensed. When material is not in contact with the sensing
element, the bridge is balanced by turning the adjustment pot to find the threshold where the red led goes out.
When material is in contact with the sensing element, the bridge becomes unbalanced and the comparing
circuit realizes the change. This causes the relay to change state.
3. INSTALLATION
A. INSPECTION
After unpacking the LS8500, visually inspect the unit for any damages.
Please advise the factory or your local distributor of any damage.
A complete unit should consist of the following:
1. An explosion proof enclosure with flange attached
2. A transmitter module in the explosion proof enclosure
3. The LS8000/R receiver card
4. A plastic snap track to mount the receiver card
NOTE: LS8000 AND LS8500 ELECTRONIC COMPONENTS ARE INTERCHANGABLE.
B. PHYSICAL INSTALLATION OF TRANSMITTER MODULE AND PROBE
1) The LS8500 is installed into the pipe using a flange.
2) CAUTION: Always take the necessary safety precautions when cutting or welding in the
coupling for the LS8500.
a) Tag and lock out the electrical power to the equipment that services the vessels.
b) Check liquid or dry powders that create a gas in the vessel for oxygen as well as the
explosion factor. (All dust will explode.)
c) Vessels that are cross vented have to be isolated.
3) Tighten the LS8500 flange into place using proper gaskets and sufficient torque to prevent leaks.
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CAUTION: ALL INSTALLATION AND WIRING MUST CONFORM TO NEC AND ALL
OTHER LOCAL ELECTRICAL CODES. TAKE SPECIAL CARE IN OBSERVING
HAZARDOUS AREA SAFETY PROCEDURES. WE ASSUME NO LIABILITY FOR
IMPROPERLY INSTALLED OR WIRED UNITS.

www.babbittinternational.com Reference Manual
2020 Rev.2
NOTE: LS8000 AND LS8500 ELECTRONIC COMPONENTS ARE INTERCHANGABLE.
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www.babbittinternational.com Reference Manual
2020 Rev.2
NOTE: LS8000 AND LS8500 ELECTRONIC COMPONENTS ARE INTERCHANGABLE.
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2020 Rev.2
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2020 Rev.2
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