Lake Monitors Flow Transmitters - Manual (Page 22)

NOTE: Installation, operation and cleaning instructions for the basic flow meter
cartridge can be found in the first section of this manual. The following instruc-
tions are specifically for meters with electrical switches for flow alarms.
General Information
Lake’s Flow Alarms are typically used to make or break a set of
electrical contacts to signal a limit setting. They may be used to turn
on a warning light, sound a bell or horn, or even to shut down a
process. The switches on the alarm can be configured to open or
close a contact for an increasing or decreasing set point. Decreasing
flow set points may be located anywhere in the lower 2/3 of the scale
while increasing set points may be located anywhere in the upper
2/3 of the scale.
Overview
Illustration 1 shows the primary mechanism for a single-switch flow
alarm. Dual-switch flow alarms contain two sets of these same com-
ponents, but have a slightly different electrical wiring diagram (Wiring
to the DIN connector is described on page 24.) The factory default
configuration for the alarm switch is for decreasing flow, as shown in
Illustration 1. Dual alarm units contain one additional switch config-
ured for increasing flow. If an increasing flow alarm is desired, it
should be specified when the unit is ordered.
The follower moves in
unison with an orifice plate
inside of the unit’s pressure
vessel via a magnetic
coupling in order to indicate
flow rate. As the follower
moves with changes in
flow rate, the flow rate is
determined by relating the
position of the flow indica-
tor line to the increments
on the flow rate scale.
Page 22 / Flow Alarms / Lake Manual
Illustration 1
FOLLOWER
POINTER
SWITCH GLIDE
SCREW
ALARM
SWITCH
FLOW INDICATOR
LINE
FLOW RATE
SCALE