ITT McDonnell & Miller FS1 Series Installation and operating instructions

®
Series FS1
High Sensitivity
Liquid Flow Switch
Series FS1
Series FS1-W
• Before using product, read and understand instructions.
• Save these instructions for future reference.
• All work must be performed by qualified personnel trained in the proper application,
installation, and maintenance of plumbing, steam and electrical equipment and/or systems in
accordance with all applicable codes and ordinances.
• To prevent electrical shock, turn off the electrical power before making electrical
connections.
• To prevent an electrical fire or equipment damage, electrical wiring insulation must have a
rating of 167˚F (75˚C) if the liquid’s temperature exceeds 180˚F (82˚C).
• To prevent electrocution, when the electrical power is connected to the flow switch, do not
touch the terminals.
• Make sure flow switch electrical cover is secured before turning on electric power.
Failure to follow this warning could cause property damage, personal injury or death.
WARNING CAUTION
!
WARNING
OPERATION
This control is an independently mounted water flow
sensing device that makes or breaks an electrical
circuit when flow stops or starts.
(specified models only)
McDonnell & Miller
Installation & Maintenance
Instructions
MM-615A)

2
Maximum Liquid Pressure: 100 psi (7 kg/cm2)
Liquid Temperature Range (TL): 32 - 225˚F (0 - 107˚C)
Ambient Temperature Range (TS): 32 - 120˚F (0 - 49˚C)
Electrical Enclosure Rating: Nema Type 1 (IP 21)
(All models except “W”)
Nema Type 4X (IP 56) (“W” models)
Maximum Velocity: 10ft/sec (3M/sec)
Pipe Connection Thread Size: 1/2” NPT
(All models except “J”)
1/2” BSPT
(“J” models)
Models that meet CE Conformance:
FS1-J-E
FS1-W-E
• This Control: is for continuous operations
is not electronic
has Type 1C action (micro interruption
on operation)
• LVD 73/23/EEC
• EMC 89/33/EEC
For applications with loads between 0.5 and 3.7 Amps,
power factors exceeding 0.65, an anticipated system
switch operation rate of less than once per 2.5 minutes,
and any one cycle greater than 3 seconds on and 3
seconds off.
For applications with loads 0.5 and 38mA, power fac-
tors exceeding 0.65, an anticipated system switch
operation rate of less than once per 5 minutes, and any
one cycle greater than 3 seconds on and 3 seconds off.
Additional suppression may be required for applica-
tions outside these ranges.
• Declaration of Conformity
Available on request.
SPECIFICATIONS
NOTE: Switch on ‘G’ models is rated for 750mA @ 24VAC and 24VDC. This
switch should only be used on low voltage (24 VAC or less) or millivolt systems.
Motor Switch Rating (Amperes)
Voltage Full Load Locked Rotor Pilot Duty
120 VAC 7.4 44.4 125 VA at
240 VAC 3.7 22.2 120 or 240 VAC
50 or 60 cycles
ELECTRICAL RATINGS
CE Circuit Rating
7.4 (7.4)/120~ 0.3/120=
3.7 (3.7)/240~ 0.15/240=

P10 20 30 40 50 60 70 80 90
8.35 11.50 13.60 15.75 17.75 19.75 21.25 23 24.25
Mode of Operation
Flow No Flow
Settings gpm (lpm) gpm (lpm)
Factory or
Minimum 0.41 (1.55) 0.24 (.91) 25
Maximum 1.81 (6.85) 1.28 (4.84) (95)
FLOW RATES
Flow rates required to activate flow switch are shown
in chart below. The values are calculated for sensing
water (potable, non-polluted) in a horizontal pipe.
Settings will vary when used to sense flow of other
fluids.
3
NOTE: DO NOT USE LIQUID FLOW
SWITCHES ON SYSTEMS WITH
FLOW VELOCITY GREATER THAN
10 FEET (3M) PER SECOND.
INSTALLATION –
STEP 1 - Determine the Location of the Flow Switch
D
5 x D
MINIMUM
1/2" PIPE
5 x D
MINIMUM
FLUID FLOW
D= PIPE DIAMETER
• The flow switch should be located in a horizontal
section of pipe
where there is a straight horizontal
run of at least 5 pipe diameters on each side of the
flow switch.
• The flow switch
must be installed in the upright
position as shown with arrow mark on side of casting
in the same direction as fluid will flow.
• Some system conditions that require more than 5
pipe diameters are high viscosity fluid and high fluid
velocity.
NOTE: “L” models are set at the factory to prove flow at 1.7 gpm. The setpoint should not be adjusted in the
field without consulting factory.
Flow Rates
Values are ± 10%
Max. Flow Rate
gpm (lpm) w/o
Paddle Damage
PSI Flow Switch Capacity - FSI
DIFFERENTIAL
PRESSURE
GPM
CAPACITY

4
STEP 2 - Connecting the Flow Switch to Pipe
FLOW
b. Insert pipe threads into flow switch and turn 2
or 3 times until tight.
• Place one pipe wrench on hex fitting of flow
switch and one wrench on connecting piping.
Tighten to following torque values.
- 31 ft•lb (42 N•m) for 1/2” pipe
• Repeat to connect pipe to opposite side of
flow switch.
a. Apply pipe sealing compound or Teflon®tape to the
pipe threads.
NOTE: Do not apply sealant to first threads as this
switch is grounded (earthed) via the pipe mounting.

5
A
a. Cover Removal and Installation Procedure
For FS1 models with NEMA 1 Enclosure
• Using a flathead screwdriver, loosen but do not
remove the two cover screws and remove the
cover (A).
• Place the cover on the flow switch sliding the slots
behind the two loose cover screws. Push the cover
down into the flow switch and using a flat blade
screwdriver, tighten the cover screws to a torque of
10 lb•in (1.13 N•m).
For FS1-W models with NEMA 4X Enclosure
• Using flathead screwdriver, unscrew the six cover
screws and remove cover.
• Place the electrical connection cover on the flow
switch and insert the six cover screws. Tighten the
screws to a torque of 10 lb•in (1.13 N•m).
STEP 3 - Electrical Installation
• To prevent electrical shock, turn off the electrical power before making electrical connections.
• To prevent an electrical fire or equipment damage, electrical wiring insulation must have a rating of
167˚F (75˚C) if the liquid’s temperature exceeds 180˚F (82˚C).
• To prevent electrocution, when the electrical power is connected to the flow switch, do not touch the
terminals.
• Make sure flow switch electrical cover is secured before turning on electric power.
Failure to follow this warning could cause property damage, personal injury or death.
!
WARNING
b. Electrical Conduit Connection
• Connect electric conduit to flow switch electrical enclosure.
• Follow accepted electrical practices when installing fittings
and making connections.
• Refer to and follow local codes and standards when
selecting the types of electrical fittings and conduit to
connect to flow switch.

6
d. Based upon the mode of operation (“Flow” or “No-
Flow”) required, complete the appropriate steps to
connect wires to flow switch. Use a Phillip’s head
screwdriver to loosen and tighten switch terminal
screws when attaching wires.
For “Flow” Mode of Operation (Fig. 1)
If the flow switch will be used to actuate a signal,
alarm or other device when
flow occurs, connect
the wire from that device to the “N.O.” contact.
Connect the “Hot” power supply wire to “C” terminal.
For “No Flow” Mode of Operation (Fig. 2)
If the flow switch will be used to actuate a signal,
alarm or other device when
no flow occurs, connect
the wire from that device to the “N.C.” contact.
Connect the “Hot” power supply wire to “C” terminal.
Flow
Opens
Circuit
Normally
closed
3
Common
1
Flow
Closes
Circuit
2
( (
Normally
open
( (
Common
( (
FS4-3 LINE
LOAD
Fig. 1
HOT
31
2
FS4-3 LINE
LOAD
Fig. 2
HOT
31
2
c. Determine which switch action is required for the
flow switch.
• “Flow” means that the switch will close circuit
C.-N.O. and open circuit C.-N.C. when flow rate
is increased above setpoint of flow switch.
• “No Flow” means that the switch will open circuit
C.-N.O. and close circuit C.-N.C. when flow rate
is decreased below setpoint of flow switch.
NOTE: Do not adjust these screws.

7
a. Place cover on flow switch and turn on power. Initiate fluid
flow through the system. Observe the device being
activated by the flow switch to determine if device is
operating as required.
b. Turn off fluid flow to determine if device is operating
as required.
c. Repeat initiating and turning off fluid flow several times to
test flow switch and device for proper operation.
- If operating as required, put system into service.
- If not operating as required, flow switch may need
to be adjusted.
OFF
ON
SECTION 4 - Testing
STEP 5 - Adjustment
1/2" Pipe Connection
Adjusting Screw
Adjustment is necessary only if required flow/no
flow setpoints are above factory set minimum.
a. Turn off power.
b. Locate adjusting screw on bottom of unit.
c. Turn adjusting screw clockwise (1/8 turn) to
increase setpoint.
d. Turn on power.
e. Test the operation of the flow switch after
each adjustment.
IMPORTANT: Do not attempt to lower flow switch
setpoint from original factory minimum setting.
Lowering (turning adjusting screw counterclock-
wise) the setpoint from original factory setting
may cause erratic flow switch operation.