BABBITT INTERNATIONAL INCORPORATED

LS2000

Low-Cost Sensor


LS6000

Basic Features Sensor


LS7000

Full-Featured Sensor


LS7000/2

Dual-Point Sensor


LS8000

Full-Featured Sensor with Remote Electronics


LS8000/2

Multi-Point Sensor with Remote Electronics


LT9000

Level Transmitter


Liquid Level Gauge


Magnetostrictive Level Transmitters
MLS-4EX

Multipoint Float Level Switch


Ultrasonic Level Gage


RADAR

RADAR Level Transmitter


FS10000

Dust Emission Flow Switch


FT4100

Dust Emission Flow Transmitter


BPS 400

Bag House and Dust Collector Differential Pressure Sensor


BPS 402 Control Panel

Bag House and Dust Collector Filter Monitor and Cleaning Cycle Control Panel


API 4058G

Bag House and Dust Collector Filter Sensor Transmitter


Pumping Down a Sump Using One Level Switch with an Off-Delay Timer


Schematic 1 High/Low level switches used for automatic filling of a tank.
Dual-point level switch used with timer level control
Pressure vessel level control
Bag house/dust collector filter monitoring and cleaning control

This level control application uses only one Babbitt LS7000 level switch to control automatic pumping down of a sump.

When the level rises to point "A", the pump turns on. The pump continues to run, emptying the tank, until the timer turns it off.

The pump motor starter is activated by 115VAC control voltage at the Level Switch #1 relay contacts. Wiring terminations are made between Common (C1) and and Normally Closed (NC1). The switch is set at "Fail-Safe High", which means that it will energize the relay output upon absence of liquid at the probe, and de-energize the relay upon presence of material at the probe. In addition, the Timer that is built in to the Level Switch electronics is set for OFF delay for one minute. Schematic 2

The Level Switch will de-energize (closing the NC contact) as the level rises and touches the probe. To keep the pump running as the level falls, the Off-delay timer keeps the Level Switch relay de-energized until the preset time is reached. In this example, we chose one minute to pump down. The time range is selectable from 1/8 second to 2 hours.

Level Switch "B" is set for "Fail-Safe High" (energize upon absence of material at the probe) with the wiring terminations made between Common (C1) and Normally Open (NO1) on the #1 relay contacts. Level Switch "B" must energize the relay output to enable the pump to run. When the level rises to point "B", Level Switch "B" will de-energize, and shut off the pump motor.

The second set of contacts on the Level Switch relay, C2 and NC2, are used to provide remote indication that the Pump should be running.

This Fail-Safe logic is used to prevent accidental overfill if Level Switch B's wiring is cut or relay contacts are burned.

Advantages:

Pricing: $400 to $600, depending on probe length and material.

We invite you to contact us with your next application.