1. technology and computing
2. hardware
3. computer networking
4. router

Differential pressure flow switch
WFS10/11/14 Series
FLOW
Air Conditioning OnLine Controls
Overview
The WFS1 Series differential pressure flow switch was designed to be compact, cost-effective differential pressure
switch for application such as proof-of-low, filter monitoring, etc. It is one of the most important applications in HVAC
controlling system. It depends two opposing diagrams to sense pressure on the “High” and “Low” pressure output of a
system. The resulting pressure differential is transmitted through a linkage to a snap-action electrical switch, providing
an output when a pre-set difference is exceeded. It is the substitute for the target flow switch.
Features
Compact size/Good stability /Easy to install/Adjustable ranges /Optional status light/Accurately control /No resistance
effect on water system
Application
Typical applications include flow controlling and monitoring for pump and filter in air-cooled water chiller、water-cooled
chiller those use plate-type heat exchanger、double-pipe heat exchanger and shell-and-tube heat exchanger.
Nomenclature
WFS1
WFS1
0
030
A
A
1A
B
0
E
Specification
WFS1 Differential Pressure Flow Switch
Set point: single fixed
Set point: single adjustable
Set point: double adjustable
0
1
4
Differential pressure :A. fixed type is closed differential
pressureǗB. adjustable type is maximum adjustable rangLj
UnitǖkPa
030
…
…
High-pressure connectionǖ7/16ŅUNF male threadDŽ1/4Ņ
SAEDž
A
B
High-pressure connectionǖ1/4ŅNPT male threadDŽG1/4ŅDž
Low-pressure connectionǖ7/16ŅUNF male threadDŽ1/4Ņ
SAEDž
Low-pressure connectionǖ1/4ŅNPT male threadDŽG1/4ŅDž
Cable: plain connector, the letter indicates connection mode,
see the wiring schematic drawing (only for WFS10)
A
B
1A
2A
Cable: DIN43650 the letter indicates connection mode, see the
wiring schematic drawing (only for WFS10)
3A
Cable: terminal block wiring, the letter indicates status light
option, see the wiring schematic drawing (only for WFS11Ă
14)LjAǖno status lightLjBǖoutside 220VACLjCǖoutside
24VACLjDǖoutside 24VDC
B
L
K
0
2
3
E
N
ACOL(shanghai) Online Controls Co.,Ltd
Shell colour: black (recommended)
Shell colour: blue (custom-made)
Shell colour: custom-made
Cavity material: H59 brass
Cavity material: S316 stainless steel
Cavity material: reinforced plastic
Diaphragm material: EPDM, apply to waterĂ air, but oil is
prohibited, temperature resistance: Ľ80ņ
Diaphragm material: NBR, apply to water Ăair and oil,
temperature resistance: ļ80ņ(WFS11Ă14 series with this
diaphragm)
Http://www.acol.cn
WFS1-series 1/18
Differential pressure flow switch
WFS10 Series
FLOW
Air Conditioning OnLine Controls
Overview
The 10 series differential pressure flow switch with single fixed set point was
designed for OEM customers. It was designed to be compact, cost-effective,
differential pressure switch for application such as proof-of-flow, filter
monitoring, etc. The pre-setting value can not be changed, which can ensure
the flow setting value can not be changed. ACOL company considerate
the practical situation, can transfer the setting differential pressure value to
the flow protection value of the heat exchanger. The value can set by our
professional according to customer’s requirement and print on the label.
Features
Metering substances
water
gas
Please indicate your metering substances with your order.
Dimensional drawing
DIN 43650 connector (optional)
ACOL(shanghai) Online Controls Co.,Ltd
△ Storage temperature: －29℃～82℃
△ Ambient temperature: －20℃～71℃
△ Media temperature range: －20℃-93℃
△ Pressure connection: 1/4" SAE(7/16" –20UNF)G、1/4"NPT for optional)
△ Max. static pressure: 10bar
△ Max. pressure difference: 5bar
△ Set point repeatability tolerance: ±1%
△ Output: one SPDT dry contact output, one or two for optional factory set
one N/O.
△ Switch: 10A(max)、125/250VAC
△ Electrical connection: DIN 43650 /direct connect（105℃ resistance
burning 2×0.75 or 3×0.75mm for optional）
Set point parameters
Model
Set point
Hystersis
WFS10002
WFS10003
WFS10004
WFS10005
WFS10006
WFS10008
WFS10010
WFS10011
WFS10012
WFS10013
WFS10014
WFS10017
WFS10020
WFS10025
WFS10030
WFS10035
WFS10040
2kPa
3kPa
4kPa
5kPa
6kPa
8kPa
10kPa
11kPa
12kPa
13kPa
14kPa
17kPa
20kPa
25kPa
30kPa
35kPa
40kPa
0.8kPa
1kPa
1.2kPa
1.5kPa
1.5kPa
1.7kPa
2kPa
2.3kPa
2.5kPa
2.5kPa
3kPa
4kPa
5kPa
6kPa
7kPa
8kPa
8kPa
Http://www.acol.cn
WFS1-series 2/18
Differential pressure flow switch
WFS10 Series
FLOW
Air Conditioning OnLine Controls
Wiring schematic drawing(DIN 43650connector)
Conventional wiring
schematic drawing
A
Switch closed and power supply
indicating wiring schematic drawing
E
switch open wiring
schematic drawing
C
switch closed wiring
schematic drawing
B
Switch open and power supply
indicating wiring schematic drawing
F
switch open wiring
schematic drawing
D
Switch open and closed wiring
schematic drawing
G
Wiring schematic drawing(plain connector)
blue
brown
N/O wiring schematic drawing
A
blue
brown
N/C wiring schematic drawing
B
ACOL(shanghai) Online Controls Co.,Ltd
green
red
blue
N/O and N/C wiring schematic drawing
C
Http://www.acol.cn
WFS1-series 3/18
Differential pressure flow switch
WFS11、14 Series
FLOW
Air Conditioning OnLine Controls
Overview
The series differential pressure flow switch with adjustable set point is
designed for the field has different requirements on differential pressure, for
applications involving in differential pressure monitoring of filter 、pump、
heat exchanger and water chilling unit. It outputs a warning or cut off signal
when the flow exceed or drop below a specific value.
It is also can be used for monitoring of pump and filter. The value could be
calibrated directly by professionals according to customer's requirement, and
printed the calibrated value on the label of product, so user needs not readjust
in the field. The OEM customer could calibrate by professional instrument
according to the differential pressure required by equipment, and ACOL could
provide relevant service.
Differential pressure flow switch with adjustable set point in HVAC system
has the same performance with fixed set point switch, they are substitutes
of target flow switch, avoid repairing or changing the target flow switch every
year.In order to meet user’s requirements, we developed the differential
pressure flow switch with double adjustable set points to control the high
and low pressure difference. In HVAC system, used for controlling of watercooled condenser and evaporator and monition of the dirty and blocking and
indicating application, the status light is optional.
Technical parameters
Metering substances
water
gas
oil
Please indicate your metering substances with your order.
△ Storage temperature: －29℃～82℃
△ Ambient temperature: －20℃～71℃
△ Media temperature range: －20℃～93℃
△ Pressure connection: 1/4" SAE(7/16" –20UNF)G 、 1/4"NPT etc for
optional
△ Max. static pressure: 10/16/20 bar
△ Max. pressure difference: 10/16/20 bar
△ Set point repeatability: ±1%
△ Output mode: WFS11--- one SPDT dry contact output, terminal blockwiring
WFS14--- two SPDT dry contact output, terminal block wiring
△ Switch: 3A (max) 125/250VAC
Dimensional drawing
external set
point adjusting
fixed hole
water-proof
cable connector
interface
ACOL(shanghai) Online Controls Co.,Ltd
Http://www.acol.cn
WFS1-series 4/18
Differential pressure flow switch
WFS11、14 Series
FLOW
Air Conditioning OnLine Controls
Set point parameters
Model
Set point range 1/Set point range 2
Hystersis 1/Hystersis 2
Differential pressure flow switch with single fixed setpoint
WFS11015
5ċ15kPa
WFS11030
5ċ30kPa
WFS11070
6ċ70kPa
WFS11100
6ċ100kPa
WFS11200
10ċ200kPa
WFS11300
20ċ300kPa
WFS11400
30ċ400kPa
Differential pressure flow switch with double adjustable setpoint
3kPa
3kPa
5kPa
6kPa
10kPa
15kPa
20kPa
WFS14030
WFS14070
WFS14100
WFS14120
WFS14150
WFS14200
WFS14300
3kPa/6kPa
5kPa/6kPa
6kPa/6kPa
5kPa/10kPa
6kPa/10kPa
10kPa/10kPa
15kPa/15kPa
5ċ30kPa/6ċ100kPa
6ċ70kPa/6ċ100kPa
6ċ100kPa/6ċ100kPa
6ċ70kPa/10ċ200kPa
6ċ100kPa/10ċ200kPa
10ċ200kPa/10ċ200kPa
20ċ300kPa/20ċ300kPa
Optional connector
1/4″SAE male thread～G1/2″male thread
1/4″SAE male thread～G1/4″male thread
A
B
1/4″SAE female thread～G1/4″male thread
1/4″SAE male thread～G3/4″male thread
H
C
Attention: All adapter connector
i s a p p l i c a b l e t o W F S 11 … A A a n d
WFS14…AA series, please indicate
with your order.
1/4″SAE female thread～G1/2″male thread
D
1/4″SAE female thread～φ8 pneumatic connector
G
F
E
1/4″SAE female thread～φ6 bite type fitting
1/4″SAE female thread capillary module unit
ACOL(shanghai) Online Controls Co.,Ltd
Http://www.acol.cn
WFS1-series 5/18
FLOW
Differential pressure flow switch
WFS10/11/14 Series
Air Conditioning OnLine Controls
Monition of the dirty and blocking and indicating appliction
The pressure difference will increase with filtering, switch is on and output a signal when reached the pre-pressure
value. If it automatically clean, the signal would be transmitted to controlling disk and then the controlling disk start to
clean and open the waste valve. If worker to clean, the warning signal will remind operator to clean.
hand-operated filter
differential pressure flow switch installation
automatic filter
differential pressure flow switch installation
Pump status and feed back to automatic controlling system
The pressure difference is stable when the flow is constant, it would be changed when the system resistance is
changed. The relation of pressure difference and flow, can refers to the pump performance data. So the differential
pressure flow switch used for pump monitoring as well as the minimum flow control. When the actual pressure exceeds
the set value, the switch output a dry contact signal for controlling system to indicate the pump has flow. The status
light will indicates the pump status if it has. It is the substitute of target flow switch.
pump status detecting
differential pressure flow switch installation
Heat exchanger flow controlling
The differential pressure flow switch used for flow controlling is one of the most important applications in HVAC system.
It is the best substitutes of target type flow switch. The reset flow is the minimum value used to check whether satisfy
the requirement or not. The disconnect flow is protected instrument from decreasing flow. Following we take plate and
extension-type heat exchanger、 shell and tube type heat exchanger examples to introduce the characteristics of
differential pressure flow switch.
ACOL(shanghai) Online Controls Co.,Ltd
Http://www.acol.cn
WFS1-series 6/18
FLOW
Differential pressure flow switch
WFS10/11/14 Series
Air Conditioning OnLine Controls
Plate and extension-type heat exchanger:
Plate heat exchanger with compact size and high heat transmission performance, has been widely used in water
chilling unit as evaporator and condenser. It is necessary to prevent plate heat exchanger from frost damage. A great
deal of experimentation show that there is a possibility of freezing when the current flow less than the rated flow about
50%, so it is important to keep the current flow not less than 50% of rated flow. The pressure of 50% rated flow is the
protection value of plate type heat exchanger, according to this value to choose differential pressure flow switch. We
suggested to buy the fixed set point switch to ensure the value is right(the pressure difference can be tested by our
professionals )
plate type heat exchanger
differential pressure flow switch installation
extension-type exchanger
differential pressure flow switch installation
Shell and tube type heat exchanger：
Shell and tube type heat exchanger used in water cooling unit as evaporator and condenser. The unstable flow directly
influence the mainframe, so it is important to control the flow to ensure mainframe work normally. The pressure of 70%
( recommended ) rated flow is the lower limit of protection value, we can obtain it according to the pressure and flow
curve or measure in the field. You can consult the professionals of the ACOL for specific method. We suggest to buy
double set points adjustable differential pressure flow switch, one of them can be used to indicate the heat exchanger
cleaning status. Set the reasonable pressure difference and choose the status light, when the waste is overmuch, the
status light is on to remind the user to clean heat exchanger. Avoid energy waste because of the heat transfer effect
drops and influence main engine work.
shell and tube type heat exchange
differential pressure flow switch installation
ACOL(shanghai) Online Controls Co.,Ltd
Http://www.acol.cn
WFS1-series 7/18