Dwyer BFM - Manual (Page 5)

SOUNDING AN ALARM TO INDICATE DECREASED
FLOW:
An alarm will sound when flow drops below the preset amount
(Fig. 11):
• When flow drops the relay contacts close to energize the
alarm.
• The power to the alarm (connected to the COM terminal) is
from the motor starter circuit so the alarm can only sound
when the motor is running. When the motor Stop button is
pressed the alarm will silence.
MACHING
SUPPLYING
MATERIAL
MOTOR
STARTER
START
SWITCH
TB2
COM
N/0
N/C
AC COM
117VAC
ALARM
NOTE: AUXILLARY SET OF
NORMALLY CLUSED
CONCACTS (CLOSED WHEN
STARTER IS ENERGIZED).
SHUTTING DOWN EQUIPMENT WHEN FLOW
DECREASES:
Equipment shut down mode is required if the flow rate drops
below the preset level. The relay is often wired to stop the
equipment that is supplying the material (Fig. 12 and 13).
STOP
START
STARTER
COIL
NORMAL STARTER CIRCUIT
Before the “controlled” equipment can be started again, the
following must occur:
• Material is flowing past the BFS-1 sensor.
• The Green L.E.D. (FLOW) indicator light is lit indicating
material flow.
• You may have to hold down the Start button until flow
reaches the preset rate.
As long as material continues to flow past the BFS-1 sensor
above the preset rate, the machine equipment supplying mate-
rial will continue to run. If the rate of material flow falls below
the preset level, the relay will open and the machine equip-
ment supplying the material will stop.
STOP
START
STARTER
COIL
TB2
COM
N / 0
M / C
STARTER CIRCUIT WITH BFM SHUTDOWN
Figure 11
Figure 12
Figure 13
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