Principle Of Operation - Siemens Sitrans LPS200 Betriebsanleitung

SITRANS LPS200 Introduction
Notes
• Installation, maintenance, and commissioning must be performed by qualified
technical personnel.
• SITRANS LPS200 must be used only in the manner outlined in this instruction
manual.
The SITRANS LPS200 rotating paddle switch is used for level monitoring of bulk
materials. It can be used to detect full, demand, or empty conditions in silos, hoppers, or
storage vessels of materials such as grain, feed, cement, plastic granulate, and wood
chips. The paddle switch measures bulk densities as low as 100 g/l (6.25 lb/ft
standard measuring vane, or 35 g/l (2. 1 9 lb/ft
SITRANS LPS200 Features
• High integrity mechanical seal
• Switch-selectable power supply
• Unique friction clutch mechanism. When the measuring vane encounters sudden
resistance, the friction clutch slips to prevent internal component damage.
• NPT, BSP process connections
• Rotatable enclosure
• Optional hinged vane for use with low bulk density materials
• Compact, rigid extension and cable extension configurations available
• High temperature and high pressure models available
• Optional extension kit available for the compact version
SITRANS LPS200 Applications
• Grain, feed, cement, plastic granulate, wood chips, rice, soybeans, etc.
• Low or high bulk density materials

Principle of Operation

A low revolution gearing motor drives a rotating measuring vane. When material reaches
the rotating vane, rotation stops, actuating a microswitch contact closure. When the
vane is no longer covered, rotation resumes and the microswitch reverts to its normal
condition.
The synchronous induction motor is freely suspended within the housing. When the
rotation is slowed by the material, the reaction torque is used to operate a micro-switch
that gives an electrical signal to stop the motor. When the material level moves away
from the rotating vane, a spring draws the motor back into operating position, the
microswitch returns to operating position, and the motor is switched back on.
Two motor speeds are available:
Page EN-2
1 rpm, for storage silos
5 rpm, for faster process requirements
SITRANS LPS200 – INSTRUCTION MANUAL
3
) with the optional hinged vane.
3
) with the
7ML19985FS61