KELCO F21 Series Installing And Operating Information

Vendor Manual - Heavy Duty Flow Switch - Kelco - Model F21 - Installation Operation and Maintenance Manual
INSTALLING AND OPERATING THE KELCO F21 SERIES FLOW SWITCH
Please read these installation and operating instructions fully and carefully before installing or servicing this level switch. The F21 Series flow 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
This F21 flow switch may have been supplied in one of several available configurations. The model number of the specific switch is located inside the lid of the electrical housing. The
F21 series flow switch is a versatile heavy-duty paddle flow switch suitable for detecting flow of liquids in pipes of any diameter from 25 mm (1") upward. This flow 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 flow
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 flow. Pumping systems can be manually started by pressing this button and holding it in until flow 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 flow
switch while it is pressed.
Select a location for the flow switch in a straight run of pipe, ideally with five pipe diameters of straight pipe either side of the switch. This will ensure a linear non turbulent flow acts
against the paddle of the switch. Do not install the flow 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 flow of liquid past the paddle, and to obtain a stable non-chattering response from the flow switch. The F21 flow 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 flow switch has an extra long paddle so it can be used in large diameter pipes. The paddle will require trimming if the flow
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 flow response can be obtained by
narrowing down the paddle and avoiding turbulence close to the walls of the pipe. The F21 flow 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 fit the flow
switch. This may be a tapping saddle or a pipe tee fitted with a threaded reducing bush, or a socket welded directly to the pipe. Ensure
that whatever fitting is used, sufficient 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 flow 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 flows 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 flats 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 flow switch may result. Align the flow switch
squarely to the axis of the pipe, with the direction of flow arrow on the side of the switch body parallel to the axis of the pipe and aligned
in the direction of flow. The F21 will not function correctly unless alignment is correct. When installing the flow switch in vertically
aligned pipework, the sensitivity of the switch will be slightly increased; it will detect lower flows when flow is downward, and the
sensitivity will be slightly decreased when flow 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 flows where long paddles may be used.

ELECTRICAL DATA MICROSWITCH MODELS

RATED NON INDUCTIVE LOADS
VOLTAGE
RESISTIVE LAMP LOAD
LOAD
NO NC NO
125 VAC 15A 3A
250 VAC 15A 2.5A
500 VAC 10A 1.5A
8 VDC 15A 3A
14 VDC 15A 3A
30 VDC 6A 3A
125 VDC 0.5A 0.5A
250 VDC 0.5A 0.5A
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.
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.
SWITCH CONTACT
TYPE
DRY CONTACT S.P.D.T BREAK
REED SWITCH BEFORE MAKE
Q-Pulse Id: VM465
a fully qualified and licenced electrician.

INTRODUCTION

INSTALLATION

INDUCTIVE LOADS
INDUCTIVE MOTOR LOAD
LOAD
NC NO NC NO
1.5A 15A 5A
1.25A 15A 3A
0.75A 6A 1.5A
1.5A 15A 5A
1.5A 10A 5A
1.5A 5A 5A
0.25A 0.05A 0.05A
0.25A 0.03A 0.03A

ELECTRICAL DATA REED SWITCH MODELS

SWITCHED SWITCHED VOLTAGE
POWER MAXIMUM
20W / VA 140V AC
MAXIMUM 150V DC
Active: 27/10/2014
WARNING

OPERATING LIMITATIONS

Model
Maximum operating pressure
(Static or Dynamic) at ambient
temperature
NC
2.5A
Minimum burst pressure at
ambient temperature
1.5A
0.75 Maximum operating
temperature
2.5A
2.5A Minimum operating
temperature
2.5A
Minimum liquid S.G.
0.05A
0.03A
SWITCHED CURRENT CARRY
(RESISTIVE) CURRENT
1 AMP 2 AMP
MAXIMUM MAXIMUM
F21-S F21-SS
(All Poly) (Stainless)
18 Bars 200 Bars
(261 PSI) (2900 PSI)
45 Bars 500 Bars
(652 PSI) (7251 PSI)
60ºC 80ºC
See note
below
0ºC 0ºC
0.8 0.8
BREAKDOWN TYPICAL
VOLTAGE APPLICATIONS
200V MINIMUM PLC, TELEMETRY & GENERAL
LOW VOLTAGE CONTROL
APPLICATIONS
Page 1 of 4
F21-D
(Diesel)
200 Bars
(2900 PSI)
500 Bars
(7251 PSI)
80ºC
0ºC
0.8