Babbitt LS7000 Full-Featured Sensor - Manual (Page 4)

2. THEORY OF OPERATION
The LS7000 employs a radio frequency (RF) balanced impedance bridge circuit to detect if the probe is in
contact with the material that is to be sensed.
When material is not in contact with the probe, 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 probe, the bridge becomes unbalanced and the comparing circuit realizes
the change. This causes the relay to change state.
3. INSTALLATION
* 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.
A. Inspection and Operation
After unpacking the LS7000, visually inspect the unit for any damages. Please advise the factory or your local
distributor of any damage. Before installing the unit, a simple operational check can be performed.
*THIS IS AN EXCELLENT TIME TO SET THE TIME DELAY IF IT IS TO BE USED IN YOUR
APPLICATION.
(See calibration instructions, section 4, A)
On the bench, hook up the appropriate power to L1 and L2. The operating voltage of the LS7000 is marked on
the power supply board.
Hold the unit so that the probe is not touching any surface and press the test switch.
When the test switch is depressed, the red led should come on. This simulates product touching the probe. If a
timing mode has been selected it will operate as if installed.
NOTE: The timing mode can be adjusted when checking the unit but the sensitivity adjustment
MUST BE MADE AFTER the unit is installed where it will be used.
B. Physical Installation
1) The LS7000 is installed into the vessel wall using a 1” NPT connection.
This can be either a threaded coupling or a tapped entry such as a flange.
2) The teflon insulator should always extend at least 2” through the vessel wall.
3) Always check for physical room around the location you have chosen to allow for installation. Allow 3.25”
turning radius to screw the probe in and clearance above for the length of the probe.
4) CAUTION: Always take the necessary safety precautions when cutting or welding in the
coupling for the LS7000.
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.
5) Screw the LS7000 into the connection provided. In dry material application, no sealant on threads is
required. On liquid, teflon or a good pipe thread sealant may be used.
6) The LS7000 has a 1” NPT conduit entry. When wiring these units, conform to the National Electrical Code
and any other city or company codes.
7) Always install the electrical connection into the 1” NPT on the LS7000 so water will not follow the
connection routing into the threads of the 1” NPT hub. To guarantee that condensation and water will stay
outside the unit, install an EYSM unilet before each LS7000 and fill with explosion proof sealing cement.
8) When required, the LS7000 probe can be bent to meet your special application. Remember to allow 2” of
clearance between the probe and the vessel wall. If the probe is to be used in a pressure application, the
factory must bend the probe to your specifications.
9) Location of probes on high level installations is more critical on dry material than liquids. Note the
following:
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