Introduction; Application; Operation; Mounting & Adjustment - ABB LMS100 Series Operating Instructions Manual

1.0 Introduction

The LMS100 is a magnetically actuated single pole, double throw
switch. When the LMS100 is mounted on a KM26 Magnetic
Level Gauge, LS Series Cage Level switch or an External Cham-
ber that contains a magnetic float, it can sense high or low levels
within a vessel. The unique magnetic coupling action eliminates
the need for seals, diaphragms, spring or torque tubes. There is
no physical contact with the process. Magnetic coupling also
eliminates the necessity of process connections and ensures total
isolation from the process.

2.0 Application

The LMS100 will provide either a normally open or normally
closed dry contact which may be used to activate external devic-
es such as alarms or solenoids. Its main application is to sense
the passing of a magnetic float in a KM26, or similar chamber,
attached to a vessel containing a fluid. These trip points can be
used for alarms or to activate a pump motor starter relay.

3.0 Operation

The LMS100 consists of a form C reed switch and a magnet.
The reed switch uses precious metal contacts in an inert gas at-
mosphere sealed by glass to metal bond. A magnetic float travel-
ing relative to the LMS100 causes the reed switch to change
state. After the float has passed, the reed switch will maintain its
state until the float reverses direction and passes the switch in
the opposite direction. The action of the switch is break before
make. The hermetically sealed contacts serve to ensure a high
degree of hazardous area safety, weather resistance and general
reliability of the product.
4.0 Mounting & Adjustment
The LMS100 is mounted using two stainless steel clamps that
pass around the mounting ears attached to the switch housing.
The switch can be easily positioned by loosening the clamp and
sliding the switch to the correct position on the chamber. Other
switches can be added at any time, without the concern for ad-
ditional process piping or valves. Note that two switches can be
mounted so that they can trip at the same point.
NOTE:
1. Do not use the switch on chambers with operating temperatures above 300°F
/ 149°C without using insulation between the switch and the chamber to keep
the temperature of the switch from exceeding 300°F/ 149°C. Consult factory.
2. Any conduit or fittings connected to an LMS100 magnetically activated switch
should be non-magnetic material. This is necessary to avoid interference with
the operation of the KM26 Magnetic Liquid Level Indicator or other magneti-
cally activated switches.
OI/LMS100-EN Rev. A |
LMS100 Magnetic Level Gauge Switch 3