KELCO F21 Series Wiring diagram

INSTALLING AND OPERATING THE KELCO F21 SERIES FLOW SWITCH
INTRODUCTION
This F21 ow switch may have been supplied in one of several available congurations. The model number of the specic switch is located inside the lid of the electrical housing. The
F21 series ow switch is a versatile heavy-duty paddle ow switch suitable for detecting ow of liquids in pipes of any diameter from 25 mm (1”) upward. This ow switch has several
unique features: A) The complete electrical assembly can be removed from the switch by undoing and removing the locking screw in the split clamp on the side of the switch’s electrical
housing. With the locking screw removed, the electrical housing can be pulled straight off the wet end of the switch. Removing the electrical housing allows the wet end of the switch
to be unscrewed from pipework without disturbing the cable connection to the switch. This means the paddle of the switch can be changed, inspected or trimmed without the need to
disturb the electrical connection to the switch. replace and tighten the locking screw after completing any work on the wet end of the switch. B) The standard version of the F21 ow
switch has a built-in manual override. On the end of the switch body underneath the cable entry port is a spring loaded push button. Pressing this button actuates the switch, regardless
of the state of ow. Pumping systems can be manually started by pressing this button and holding it in until ow is established. The override button can be used to test control circuits
and wiring during commissioning, without the need for water in the pipework. The button is spring loaded so it can’t be inadvertently left in the on position and only overrides the ow
switch while it is pressed.
Warning note on operating limitations: Maximum operating pressure of the Polypropylene F21-S must be linearly de-rated as operating temperature is increased so that at 60°C
the maximum permissible operating pressure for the switch is not more than one Bar Absolute.
INSTALLATION
OPERATING LIMITATIONSELECTRICAL DATA MICROSWITCH MODELS
Model F21-S
(All Poly)
F21-SS
(Stainless)
F21-D
(Diesel)
Maximum operating pressure
(Static or Dynamic) at ambient
temperature
18 Bars
(261 PSI)
200 Bars
(2900 PSI)
200 Bars
(2900 PSI)
Minimum burst pressure at
ambient temperature
45 Bars
(652 PSI)
500 Bars
(7251 PSI)
500 Bars
(7251 PSI)
Maximum operating
temperature
60ºC
See note
below
80ºC 80ºC
Minimum operating
temperature
0ºC 0ºC 0ºC
Minimum liquid S.G. 0.8 0.8 0.8
RATED
VOLTAGE
NON INDUCTIVE LOADS INDUCTIVE LOADS
RESISTIVE
LOAD
LAMP LOAD INDUCTIVE
LOAD
MOTOR LOAD
NO NC NO NC NO NC NO NC
125 VAC 15A 3A 1.5A 15A 5A 2.5A
250 VAC 15A 2.5A 1.25A 15A 3A 1.5A
500 VAC 10A 1.5A 0.75A 6A 1.5A 0.75
8 VDC 15A 3A 1.5A 15A 5A 2.5A
14 VDC 15A 3A 1.5A 10A 5A 2.5A
30 VDC 6A 3A 1.5A 5A 5A 2.5A
125 VDC 0.5A 0.5A 0.25A 0.05A 0.05A 0.05A
250 VDC 0.5A 0.5A 0.25A 0.03A 0.03A 0.03A
SWITCH
TYPE
CONTACT SWITCHED
POWER
SWITCHED VOLTAGE
MAXIMUM
SWITCHED CURRENT
(RESISTIVE)
CARRY
CURRENT
BREAKDOWN
VOLTAGE
TYPICAL
APPLICATIONS
DRY CONTACT
REED SWITCH
S.P.D.T BREAK
BEFORE MAKE
20W / VA
MAXIMUM
140V AC
150V DC
1 AMP
MAXIMUM
2 AMP
MAXIMUM
200V MINIMUM PLC, TELEMETRY & GENERAL
LOW VOLTAGE CONTROL
APPLICATIONS
The reed switch models are supplied with a high compliance single pole double throw reed switch suitable for all low wetting current and low voltage applications. Such
applications include PLC control, signalling in telemetry systems and relay logic circuits. Note: the reed switch models are not suitable for use with inductive loads such as
contactors or high wattage relays.
ELECTRICAL DATA REED SWITCH MODELS
Select a location for the ow switch in a straight run of pipe, ideally with ve pipe diameters of straight pipe either side of the switch. This will ensure a linear non turbulent ow acts
against the paddle of the switch. Do not install the ow switch in any location likely to expose it to turbulence, such as close to valves, pumps or pipe bends The idea is to install the
switch in a location where there is a smooth ow of liquid past the paddle, and to obtain a stable non-chattering response from the ow switch. The F21 ow switch can be mounted in
either the suction or discharge pipe of a pump, the switch will work equally well in positive or negative pressure applications.
The F21 ow switch has an extra long paddle so it can be used in large diameter pipes. The paddle will require trimming if the ow
switch is to be used in smaller diameter pipes. The paddle can be cut and shaped as required using tin snips or a hacksaw. Note, the
paddle can be cut both in length and if required, in width. Many installers maintain a more stable ow response can be obtained by
narrowing down the paddle and avoiding turbulence close to the walls of the pipe. The F21 ow switch can be installed in any required
orientation except on the under side of horizontal pipes.
Depending on the thread on the switch, a 25 mm, 1” BSP or 1” NPT threaded socket must be provided on the piping, to t the ow
switch. This may be a tapping saddle or a pipe tee tted with a threaded reducing bush, or a socket welded directly to the pipe. Ensure
that whatever tting is used, sufcient clearance is allowed for the free movement of the paddle. Normally a clearance to the full inside
diameter of the 1” pipe thread will be required. The F21 ow switch can be installed in a 1” pipe socket attached to a short stand off
pipe, at 90° to the main pipe. This method of mounting increases the sensitivity of the switch to low ows due to the extra leverage
against the tip of a longer paddle. If this mounting method is used make sure to leave extra clearance to allow for the full arc movement
of the longer paddle.
Use a suitable thread sealant and tighten the switch into the socket using the spanner ats provided on the switch body. Do not tighten
the switch into its socket by twisting the electrical housing of the switch, as damage to the ow switch may result. Align the ow switch
squarely to the axis of the pipe, with the direction of ow arrow on the side of the switch body parallel to the axis of the pipe and aligned
in the direction of ow. The F21 will not function correctly unless alignment is correct. When installing the ow switch in vertically
aligned pipework, the sensitivity of the switch will be slightly increased; it will detect lower ows when ow is downward, and the
sensitivity will be slightly decreased when ow is upward. This is due to the effect of gravity on the dead weight of the paddle itself.
This effect is more noticeable in larger pipes and low ows where long paddles may be used.
WARNING
Please read these installation and operating instructions fully and carefully before installing or servicing this level switch. The F21 Series ow switch is
mains voltage device. Death or serious injury may result if this switch is not correctly installed and operated. All electrical work must be performed by
a fully qualied and licenced electrician.
Vendor Manual - Heavy Duty Flow Switch - Kelco - Model F21 - Installation Operation and Maintenance Manual
Q-Pulse Id: VM465
Active: 27/10/2014
Page 1 of 4

PLEASE NOTE: Kelco Engineering Pty Ltd reserves the right to change the specication of this product without notice. Kelco Engineering Pty Ltd accepts no liability for
personal injury or economic loss as a consequence of the use of this product. All rights reserved. Copyright Kelco Engineering Pty Ltd ©2011.
KELCO Engineering Pty Ltd
ABN 20 002 834 844 Head ofce and factory:
9/9 Powells Road Brookvale NSW 2100 Australia
Postal Address: PO Box 496 Brookvale NSW 2100 Australia
Phone: [phone] Fax: [phone]
Email: [email protected] Web: www.Kelco.com.au
©2011 Kelco Engineering Pty Ltd
MADE IN AUSTRALIA BY
MAINTENANCE
ELECTRICAL
The F21 ow switch is available in one of two basic congurations. The standard
version of the ow switch is supplied with an SPDT microswitch tted. A special reed
switch version of the ow switch is also available for low power applications. The
model number of the switch is located on a label inside the switch lid. The standard
ow switch houses a magnetically coupled high current high voltage single pole
double throw microswitch that is suitable for most general-purpose control circuit
applications at any voltage up to 500VAC. The special reed switch version of the
F21 houses a gas lled reed switch that provides a single pole double throw break
before make action. The cable gland on the F21 ow switch is threaded M20 and
will accept standard M20 conduit bushes in addition to exible cable. When wiring
an F21 ow switch, ensure the lid and cable gland are securely tightened and in fully
exposed locations use secondary precautions such as cable drip loops to make sure
no water can enter the switch housing.
If the F21 ow switch is correctly installed and if the process liquid is compatible with
the materials of construction of the switch then a very long maintenance free service
life can be expected. Factors that may contribute to early failure of the F21 ow
switch include excess temperature, excessive pressure or electrical loads in excess
of the switch’s rating. Should service be required, an exploded view of the ow
switch is included to show the main components and how they t together. The F21
is a very simple switch to service, and all components are available as spare parts.
HAZARDOUS APPLICATIONS
The F21 ow switch can be used in hazardous areas. The ow switch is classed as a simple device and does not contain components capable of storing or producing an
electric charge. As a simple device the F21 can be used in hazardous applications provided an intrinsically safe barrier (a zener barrier) isolates it.
PADDLE TRIMMING AND FLOW SENSITIVITY
There are two methods of setting the sensitivity of the F21 ow switch. By far the
most effective method is by the correct trimming of the paddle. For ne tuning, a
sensitivity adjustment screw is provided, as shown in the accompanying drawing.
As supplied by the factory, the sensitivity screw is wound fully in, and is set to least
sensitivity. The adjusting screw can be wound out, and the sensitivity slightly
increased. The maximum effect is achieved with the screw wound out to a point
where the screw head is 4mm in from the face of the switch body.
By far the best way to set the F21 ow switch is to make a judgment on the likely ow
rate in the pipe, and to trim the paddle accordingly. If the ow is going to be high
then trim the paddle fairly short, and if you know the ow rate will be low then leave
the paddle as long as possible. If the ow rate is unknown then generally trimming
the paddle to half way across the pipe will achieve a satisfactory compromise and
will work well. Trimming the paddle is a compromise between sensitivity to the duty
ow and stress on the intruding paddle. Fluid ow generates force, and a certain
minimum amount of force is required by the ow switch in order to function.
Excessive force however can bend or break paddles.
The exact ow rates required to actuate the F21 will depend on many variables such
as turbulence, liquid viscosity and the exact area of the paddle face exposed to the
ow. For an accurate estimation of the switching point for any given paddle size, an
online ow calculator is available at www.kelco.com.au
WARNING
All electrical work associated with the F21 Series ow switch must be
carried out by qualied electrical personnel and all electrical work must
conform to AS/NZ (or equivalent) standards and to local wiring rules.
After installing or servicing this ow switch always replace its lid and
fully tighten its lid screw. Also ensure the cable gland is fully tightened.
Never leave the lid off the level switch for extended periods. Without its
lid in place this level switch is not water resistant and presents a potential
shock hazard. Take great care not to splash water onto the inside of the
level switch’s electrical housing when the lid is not in place. Without its
lid the level switch is not weather or insect proof and presents a potential
shock hazard that may result in death or serious injury.
WARNING
Vendor Manual - Heavy Duty Flow Switch - Kelco - Model F21 - Installation Operation and Maintenance Manual
Q-Pulse Id: VM465
Active: 27/10/2014
Page 2 of 4


F21SERIESHEAVYDUTYFLOWSWITCHES
KELCO
0 to 500V AC 15 Amp S.P.D.T switch
PLC versions available
316 Stainless or Polypropylene models
1” BSP & 1” NPT models available
Manual override built in
Modular construction
200 Bar pressure rating
Seal-less magnetic drive
Diesel models available
Weatherproof IP67 housing
Easily serviceable
FEATURES
OUTLINE
FOR ALL PIPE SIZES 25MM (1”) AND LARGER
Model F21-S
(All Poly)
F21-SS
(Stainless)
F21-D
(Diesel)
Maximum operating
pressure (Static or
Dynamic) at ambient
temperature
18 Bars
(261 PSI)
200 Bars
(2900 PSI)
200 Bars
(2900 PSI)
Minimum burst
pressure at ambient
temperature
45 Bars
(652 PSI)
500 Bars
(7251 PSI)
500 Bars
(7251 PSI)
Maximum operating
temperature
60ºC
See note
below
80ºC 80ºC
Minimum operating
temperature
0ºC 0ºC 0ºC
Ingress protection
rating
IP67 IP67 IP67
DIMENSIONSOPERATINGLIMITATIONS
Please note: Maximum operating pressure of the Polypropylene F21-S
must be linearly de-rated as operating temperature is increased so that at
60°C the maximum permissible operating pressure for the switch does not
exceed one Bar absolute.
The F21 ow switch is a tough but highly sensitive paddle ow switch suitable for a wide range
of ow control applications in both hot and cold liquids. The electrical housing of the switch is a
separate assembly and locks onto the wet end of the switch. It can be easily and safely removed
for servicing, without disturbing electrical wiring. This unique feature, and the inclusion of a built
in manual override make the F21 a very versatile ow switch. In addition to the standard
microswitch models the F21 is available tted with reed switches for PLC, relay logic and
telemetry applications.
The electrical module of the F21 ow switch is completely separate from the process connection and wet end of the switch. The wet end
assembly and the electrical module lock together with a single externally accessible screw. This feature allows the ow switch to be
disassembled and unscrewed from pipework without the need to disturb electrical wiring. All F21 ow switches are supplied with an extra
long glass bre reinforced polypropylene paddle. The paddle can be cut and shaped as required to suit pipework 25 mm (1”) or larger.
A unique feature of the standard F21 ow switch is its built in manual override. This allows the ow switch to be switched on at any time
at the press of a button regardless of lack of ow. Using the manual override allows pumps to be manually started at any time by simply
pressing the button. It also makes the testing and commissioning of systems very simple. Please note: when supplied with a reed
switch, no manual override is included in the F21.
Our well proven magnetic repulsion system is built into each F21 ow switch and couples the paddle’s movement to the high compliance
switch through a double wall of solid material. The result is a high-pressure ow switch with no seals, diaphragms or bellows or other
points of potential failure. The F21 is available in all stainless steel or Polypropylene construction. There are models to suit most
applications including use in seawater, bore water, acids, and alkalis and in many chemical solutions and fuels. There is also a dedicated
Diesel compatible version available.
Vendor Manual - Heavy Duty Flow Switch - Kelco - Model F21 - Installation Operation and Maintenance Manual
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Active: 27/10/2014
Page 3 of 4

F21 SERIES
The Kelco F21 Series ow switches are protected by a 12 month return to base warranty. Full details of
our warranty can be downloaded from: http://www.kelco.com.au/menu/information/warranty-statement/
PLEASE NOTE: Kelco Engineering Pty Ltd reserves the right to change the specication of this product without notice. Kelco Engineering Pty Ltd accepts no liability for personal injury or economic loss
as a consequence of the use of this product. All rights reserved copyright Kelco Engineering Pty Ltd © 2012
The F21 ow switch can be used in hazardous areas. The ow
switch is classed as a simple device and does not contain
components capable of storing or producing an electric charge.
As a simple device the F21 can be used in hazardous
applications provided it is isolated by an intrinsically safe barrier,
a zener barrier.
The high compliance single pole double throw switch used in
the F21 ow switch is approved to the following international
standards: UL (File No. E32667), CSA (File No. LR21642) SEV
(File No. S20/163) and CE.
SWITCH
TYPE
CONTACT SWITCHED
POWER
SWITCHED VOLTAGE
MAXIMUM
SWITCHED CURRENT
(RESISTIVE)
CARRY
CURRENT
BREAKDOWN
VOLTAGE
TYPICAL
APPLICATIONS
DRY CONTACT
REED SWITCH
S.P.D.T
BREAK
BEFORE
MAKE
20W / VA
MAXIMUM
140V AC
150V DC
1 AMP
MAXIMUM
2 AMP
MAXIMUM
200V MINIMUM PLC, TELEMETRY &
GENERAL LOW
VOLTAGE CONTROL
APPLICATIONS
RATED
VOLTAGE
NON INDUCTIVE LOADS INDUCTIVE LOADS
RESISTIVE
LOAD
LAMP LOAD INDUCTIVE
LOAD
MOTOR LOAD
NO NC NO NC NO NC NO NC
125 VAC 15A 3A 1.5A 15A 5A 2.5A
250 VAC 15A 2.5A 1.25A 15A 3A 1.5A
500 VAC 10A 1.5A 0.75A 6A 1.5A 0.75
8 VDC 15A 3A 1.5A 15A 5A 2.5A
14 VDC 15A 3A 1.5A 10A 5A 2.5A
30 VDC 6A 3A 1.5A 5A 5A 2.5A
125 VDC 0.5A 0.5A 0.25A 0.05A 0.05A 0.05A
250 VDC 0.5A 0.5A 0.25A 0.03A 0.03A 0.03A
ELECTRICAL DATA FOR STANDARD MICROSWITCH MODELS
The standard F21 ow switch is suitable for all general control circuit applications up to 500V AC. It is ideal for the control of pump
starters, relay logic circuits, and for the direct control of contactors and electronic timers.
ELECTRICAL DATA FOR REED SWITCH MODELS
The reed switch models are supplied with a high compliance single pole double throw reed switch suitable for all low wetting
current and low voltage applications. Such applications include PLC control, signalling in telemetry systems and relay logic circuits
Please note: the reed switch models are not suitable for use with inductive loads such as contactors or high wattage relays.
ELECTRICALDATA
FLOWSENSITIVITY
The ow rates required to actuate the F21 will depend on many
variables such as turbulence, liquid viscosity and the exact
area of the paddle face exposed to the ow. For an accurate
estimate of the switch performance and to determine the effect
of paddle trimming, an online ow calculator is available at
www.kelco.com.au
HAZARDOUSAPPLICATIONS
APPROVEDSTANDARDS
ORDERING
KELCO Engineering Pty Ltd
ABN 20 002 834 844 Head ofce and factory:
9/9 Powells Road Brookvale NSW 2100 Australia
Postal Address: PO Box 496 Brookvale NSW 2100 Australia
Phone: [phone] Fax: [phone]
Email: [email protected] Web: www.Kelco.com.au
©2012 Kelco Engineering Pty Ltd
MADE IN AUSTRALIA BY
Vendor Manual - Heavy Duty Flow Switch - Kelco - Model F21 - Installation Operation and Maintenance Manual
Q-Pulse Id: VM465
Active: 27/10/2014
Page 4 of 4