Seametrics FS20 - Manual

PUB 19128-1000
Page 1 of 2
FS20 Dual Flow Switch
Instructions
Designed to be used with a variety of SeaMetrics
meters, the FS20 signals when flow reaches critical
setpoints. Two setpoints are provided, a low and a high
setting. When flow falls below the low or rises above
the high, SPDT relay contacts close to actuate what-
ever alarms or controls are connected to them. Set-
ting is by means of DIP switches, and setpoints are in
pulses per minute. Output lights give visual indication
that flow limit has been reached.
Specifications
Power 115 VAC
Enclosure NEMA 4x, 5" x 7" polycar-
bonate
Relays SPST
Relay Rating 5 A resistive at 115 VAC
5 A at 24 VDC
Setpoint Range 1 - 33,000 pulses/
minute
Setpoint Hysteresis 6%
Sensor Power 25 mA at 12 VDC
nominal
Features
Mounting. To gain access to the mounting screw holes,
remove the front clear cover. Mounting screw holes
are at the four corners, under the cover screws. Mark
the centers of these holes, using the box or the en-
closed template, and drill. Finally, insert screws through
the corner holes and tighten.
Terminal Access. Terminals are on the back side of
the printed circuit board. Remove the front clear cover,
then remove the four front plate screws. Turn the printed
circuit board over to reach the terminals.
Connect Flow Meter. Bring the flow meter input cable
into the unit through the appropraite strain relief, then
connect following the Connections diagram. Either two-
wire (dry contact) or three-wire (solid state) flow meter
sensors can be used.
Connect Alarm Relay(s). Bring alarm output cable(s)
into the unit through the appropriate strain reliefs and
connect to relay outputs, as shown in the Connections
diagram. Note that depending on setting, relays may
energize when the unit is first powered up. If this
presents a hazard, disconnect any devices on the
other end of the cable(s) until settings have been
made and tested.
General Information Installation
Input Indicator
High Flow Setting Low Flow Setting
Power switch
and indicator
Cover screws
and box mounting
screw holes
strain relief
Power input cord
(6’ length)
Low flow
relay output
Internal 10 Amp
replaceable fuse
Output Indicators
OFF ON
MANUAL MANUAL
INC. KENT, WA
INPUT
LOW FLOW HIGH FLOW
FS20
FLOW SWITCH
OFF ON OFF ON
16384 16384
32768 32768
8192 8192
4096 4096
2048 2048
1024 1024
512 512
256 256
32 32
64 64
128 128
16 16
8 8
4 4
2 2
1 1
Setting equals
the sum of
the switches
turned "ON". Setting equals
the sum of
the switches
turned "ON".
L
O
W
F
L
O
W
H
I
G
H
F
L
O
W
High flow
relay output
Meter input
DIS
CON
TIN
UED