Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S E-29
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Liquid Leakage Sensor Amplifier with Disconnection Detection Function
K7L-AT50D/-AT50D-S
Detect disconnections between the Sensor
Amplifier and a Terminator connected to the
end of the Sensing Band.
•Constantly monitors for disconnections between the Sensor
Amplifier and the Sensing Band.
•Failure to detect liquid leakage due to disconnection in the
Sensing Band prevented.
•Notification of disconnection detection made using LED indica-
tor and transistor output.
•After a disconnection is detected, in order to avoid instability
due to further contact of the disconnected part, the operating
status is held.
•This model retains all the characteristics of the K7L-AT50 (de-
tection sensitivity, sensing ranges, and AC detection method).
•Meets UL/CSA standards. (See information on standards on
page 31.)
Application Examples
Liquid Leakage Detection for Measuring Baths in CMP
Devices
Detects liquid leaked to drain pans, and prevents damage to devices
and cleaning irregularities for wafers.
Detection of Condensation and Liquid Leakage at
Semiconductor Production Installations
Detects condensation inside cleaning devices and liquid leaked to
the surroundings.
Detection of Liquid Leakage at Pipe Joints for Chemical
Liquid Tanks
Liquid leakage at a pipe joint can be detected by wrapping the Sens-
ing Band around the joint.
Detection of Cleaning Fluid Level for Plating Devices
Detects the level of pure water inside plating baths. High sensitivity
allows high-accuracy control that prevents cleaning irregularities.
E-30 Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S
Model Number Structure
■Model Number Legend
1. Disconnection Detection Function
Blank: No
D: Yes
2. S: Without terminator
Ordering Information
■List of Models
Note: The Socket, Terminal Block, Sticker, and Sensing Band are the same as for the K7L-AT50.
K7L - AT50 -
12
Name Model number
Liquid Leakage Sensor Amplifier with Disconnection Detection Function
Set
K7L-AT50D
Liquid Leakage Sensor Amplifier with Disconnection Detection Function
Sensor Amplifier Only
K7L-AT50D-S
Terminator (2P) F03-20T
Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S E-31
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Controllers
Specifications
■Ratings
Note: UL File No. E138234
CSA File No. LR95291-21
■Characteristics
Rated power supply voltage 12 to 24 VDC (Allowable voltage fluctuation range: 10 to 30 VDC)
Operate resistance 0 Ω to 50 MΩ, variable
Range 0: 0 to 250 kΩ
Range 1: 0 to 600 kΩ
Range 2: 0 to 5 MΩ
Range 3: 0 to 50 MΩ
Note: The range used is set using the DIP switch on the side of the Sensor Amplifier. (Refer to DIP
Switch Settings.) Set the corresponding pin of the DIP switch in the up position. (For range 0,
set all 3 pins in the down position.) The adjuster (ADJUST) on the top of the Sensor Amplifier
sets the resistance value for detection within the set range. It is factory-set to the upper limit.
(Normally, use with the adjuster set to the upper limit.) With any range, resistance values can
be set from 0 Ω.
Disconnection detection function Detection signal: 10 VDC max., 200 ms
Detection time: 10 s max.
Release: Released by resetting the power supply.
Release resistance 105% min. of operate resistance
Output configuration NPN open collector transistor output with 100 mA at 30 VDC max. for both liquid leakage detection
and disconnection detection.
Note: If the rightmost pin of the DIP switch on the side of the Sensor Amplifier is set to the down po-
sition, the output turns ON when liquid/disconnection is detected; if it is set to the up position,
the output turns OFF.
Wiring distance Wiring cable: 50 m max.
Sensing Band length: 10 m max.
Note: These values are possible on condition that a completely insulated 3-conductor VCT cable with
a thickness of 0.75 mm2 and a dielectric strength of 600 V is used together with a Liquid Sensing
Band specified by OMRON. (A 0.2-mm2 cable can also be used.)
Accessories F03-20 Terminal Block (for connecting wiring cable and Sensing Band)
Screwdriver for ADJUST setting.
F03-20T Terminator (provided with K7L-AT50D only)
(Purchase the Sensing Band, Sensing Band Sticker, wiring cable, and Socket separately. The Terminal
Block is 3P; the Terminator is 2P.)
Ambient temperature Operating: –10°C to 55°C
Ambient humidity Operating: 45% to 85%
Insulation resistance 10 MΩ at 100 VDC between case and current-carrying parts
Dielectric strength 1,000 VAC at 50/60 Hz for 1 min between case and current-carrying parts
Power consumption 1 VA max.
Response time Operate: 800 ms max.
Release: 800 ms max.
Weight Approx. 14 g
E-32 Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S
Connections
■Block Diagram for External Connections
Output Circuit
■Connections Example
(Bottom view)
K7L-AT50D
Level input 1
Level input 2
Common
OUT+
BURN OUT+
COM−
12 to 24 VDC
F03-20 Terminal Block F03-20T Terminator
Liquid leakage
detection output
Disconnection
detection output
Open collector output
100 mA at 30 VDC
max.
Signal
transmission
Wiring cable
(0.2 mm
2
min.)
F03-16PE Sensing
Band
8
1
5
6
7
K7L
Load Load
Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S E-33
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Operation
■Disconnection Detection Function
Operation During Monitoring for Liquid
Leakage
••Short-wave signals (2.5 VAC, 3.75 Hz) for liquid leakage detection
are output from terminal 4 of the K7L.
••When there is no liquid leakage, the liquid leakage detection sig-
nals that are output are interrupted by the Terminator and the core
of the Sensing Band will be an open loop.
Operation at Liquid Leakage Detection
•When liquid leakage occurs within the sensing range, the liquid
leakage detection signals output from terminal 4 are input to termi-
nal 2 through the leaked liquid.
•The voltage of the input signals will vary with the resistance of the
leaked liquid. This voltage is compared with the detection level set
at the K7L.
•As a result of the comparison, if the K7L determines that liquid
leakage has occurred, the K7L’s output LED will light, and the liquid
detection output will either turn ON or OFF.
Operation During Monitoring for
Disconnection
•Output of disconnection detection signals starts within 2 s of power
being supplied to the K7L and is repeated at 7-s intervals.
•Disconnection signals are DC signals of 10 V max. that are output
for approximately 200 ms. During this time, the K7L is in disconnec-
tion monitoring mode, i.e. it monitors for disconnections only and
the liquid leakage detection signals are stopped.
•If there is no disconnection, the disconnection detection signals
(10 VDC) that are output pass through the Terminator and return to
the K7L. The K7L takes this as normal, i.e., there is no disconnec-
tion.
Operation at Disconnection Detection
•If there is a disconnection, the signals will be interrupted at the
place where the disconnection occurred, and will not return to the
K7L.
•If the signals do not return, when the K7L is in disconnection moni-
toring mode it will determine that a disconnection has occurred.
The output LED will flash, and the disconnection output will turn
ON.
Note: 1. Disconnection detection is only performed between terminals 2 and 4. Therefore, be sure to connect the Sensing Band between terminals
2 and 4.
2. The K7L will switch from liquid leakage detection to disconnection detection if either of the following conditions occur while liquid leakage
is detected.
•Disconnection occurs between the K7L and the place where liquid is leaked.
•While liquid leakage is detected, disconnection occurs between the place where liquid is leaked and the Terminator (F03-20T) and,
subsequently, the leaked liquid is removed (e.g., wiped up or dried).
3. During disconnection detection, liquid leakage will not be detected. Once disconnection has been detected, reset the power supply to
stop disconnection detection.
K7L
2.5 VAC (3.75 Hz) Signals interrupted by
Terminator.
K7L
K7L
10 VDC max., 200 ms
Disconnection detection signals
are not interrupted by the Termi-
nator and return to the K7L.
K7L
Signals are interrupted where the
disconnection occurred.
E-34 Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S
Nomenclature
•Set a detection range according to the impedance of the liquid to
be detected. (If the detection range DIP switches are set in a way
not shown above, the actual range used will be the largest one by
default.) For the setting procedure refer to the label on the side of
the Sensor Amplifier.
•It is possible to set the resistance value within the set detection
range using the resistance value adjuster. At time of delivery, it is
set to the largest possible value and for normal use this setting can
be used.
•The resistance value adjuster is a precision component. Do not
apply a torque to the resistance value adjuster in excess of the
specified one. Doing so may cause the resistance value adjuster to
be damaged.
Applicable torque:
•Rotational torque: 9.81 mN·m max.
•Detent strength: 29.4 mN·m min.
Dimensions
Note: All units are in millimeters unless otherwise indicated.
DIP Switch Settings
Setting Detection Range
Power indicator (green)
(Lit when power sup-
plied.)
Output indicator (red)
(Lit when output
made.)
Resistance
value adjuster
DIP switch Range number Detection range
Range 0 0 to 250 kΩ
Range 1 0 to 600 kΩ
Range 2 0 to 5 MΩ
Range 3 0 to 50 MΩ
DIP switch Output
Output OFF when liquid leakage
detected.
Output ON when liquid leakage
detected.
Mounting Hole Dimensions
Two, M3 holes
K7L-AT50D
Liquid Leakage Sensor Amplifier
F03-20T
Terminator
Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S E-35
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Accessories (Order Separately)
■Sensing Band F03-16PE
Features
•Polyethylene used for sheath to ensure high resistance to
chemicals.
•SUS316 used for core and polyethylene used for sheath to
ensure high resistance to both acidic and alkaline liquids.
•Sensing Band Stickers that use the same material as the
Sensing Band’s insulating resin are available in 2 types: ad-
hesive-tape type and screw type.
Specifications
Chemical Resistivity for the Sensing Band
Note: 1. A: Not affected at all or only very slightly affected.
B: Slightly affected but, depending on the conditions, sufficient for use.
C: Affected but may still be used. (Replace the Sensing Band immediately after detection.)
2. In order to prevent secondary fire damage, consider the effect of the atmosphere of the environment and the solution to be detected on
the Sensing Band.
3. If the Sensing Band changes shape or color when a liquid is detected, replace the Sensing Band.
Sheath Polyethylene
Core Stainless steel SUS316
Ambient operating temperature –15 to 55°C
Applications •Early detection of water leakage in computer rooms etc.
•Used in locations with low-conductivity materials.
Weight Approx. 16 g (1 m)
Material F03-16PE
Sheath Core
Polyethylene SUS316
Water A A
Acetone C A
Ammonia A A
Ethanol B A
Hydrochloric acid A C
Hydrogen peroxide solution A A
Xylene B A
Cyclohexane C ---
Trichloroethylene C A
Toluene C B
Phenol B A
Butanol B ---
Fluorine A C
Hexane C ---
Benzene C A
Methanol B A
Sulfuric acid C B
Phosphoric acid A B
E-36 Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S
Sensing Band
Note: Specify length (in meter units) when ordering.
When cleaning with a mop, for example, do not make contact with the Sensing Band.
Sensing Band Sticker
Connecting the Sensing Band
Bending the Sensing Band
In order to change the direction of the Sensing Band, bend the Sens-
ing Band in one or two places where the core is not exposed.
Note: Bend the Sensing Band approximately 4 cm (i.e., twice the dis-
tance between places where the core is exposed) away from
places where the Sticker is attached. If the Sensing Band is
bent at places further away than this, the Sensing Band may
come away from the surface.
Stripping and Connecting Terminals
1. Cut into the Sensing Band approximately 4 to 6 cm in from the
end as shown in the diagram below.
2. Strip away approximately the last 9 mm of the sheath to expose
the core (SUS line).
3. To connect to the Terminal Block, push down the top of the termi-
nal with a screwdriver and insert the core from the side. (Refer to
Dimensions on page 34.) More Sensing Bands can be connected
simply by wiring in an arch shape.
Note: Check that the wiring is secure before using the K7L in applica-
tions.
Interval Between Stickers
When securing the Sensing Band with Stickers, attach the Stickers at
intervals of 20 to 30 cm in places where the core is not exposed.
Note: 1. When using the F03-26PE (adhesive-tape model), be sure
to wipe all moisture, oil, and dust from the surface to which
the Sticker is to be attached. Failure to do so may result in
insufficient adhesion, and the Sticker may peel away from
the surface.
2. When using the F03-26PEN (screw model), before installing
the Sensing Band, it is necessary to perform stud welding.
For details on the pitch of the studs, refer to the information
on the dimensions of Sensing Band Stickers.
Model Appearance Structure Material
F03-16PE Sheath: Polyethylene
Core: Stainless steel SUS316
Model Appearance Structure
F03-26PE/
F03-26PEN for
F03-16PE
Adhesive tape (see note)
Note: The adhesive part is on the F03-26PE only.
F03-26PE
32
13
3.0
22
Material: Polyethylene
Note: 1. The holes are in the F03-26PEN only.
2. The adhesive part is on the F03-26PE only.
3.5 dia. (see note 1)
Adhesive tape (see note 2)
Cut section
Bent in 2 placesBent in 1 place
9 mm
Insert
4 to 6 cm
Exposed
part of
core
F03-20
Terminal
Block
20 to 30 cm
Sensing
Band
Sticker
Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S E-37
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Controllers
Precautions
■General Precautions
Before using the product under conditions which are not described in
the manual or applying the product to nuclear control systems, rail-
road systems, aviation systems, vehicles, combustion systems, med-
ical equipment, amusement machines, safety equipment, and other
systems, machines, and equipment that may have a serious influ-
ence on lives and property if used improperly, consult your OMRON
representative.
Make sure that the ratings and performance characteristics of the
product are sufficient for the systems, machines, and equipment, and
be sure to provide the systems, machines, and equipment with dou-
ble safety mechanisms.
■Safety Precautions
Observe the following points to ensure safe operation.
•Be sure to use a power supply voltage within the specified range.
Not doing so may result in burning or malfunction.
•Do not use the product in locations subject to flammable gases or
combustible objects. Not doing so may result in fire.
•Insert the connection points into Sockets until the connection is
locked securely. Not doing so may result in burning or malfunction.
•Do not short-circuit loads connected to output terminals. Doing so
may result in burning.
•Be sure to connect the power supply with the correct orientation.
Not doing so may result in malfunction.
■Correct Use
Installation
Attach to a panel of thickness 1 to 5 mm.
Do not install in the following locations.
•Locations subject to shock or vibration.
•Locations where the temperature or humidity lies outside the speci-
fied range, or where condensation is likely to occur. (To detect liq-
uids with high impedances, do not use in locations with high
humidity.)
•Locations subject to dust.
•Locations subject to corrosive gases (particularly sulfide and
ammonia gases).
•Outdoors or locations subject to direct sunlight.
•Near devices that generate strong high-frequency noise (e.g., high-
frequency welding devices etc.).
E-38 Liquid Leakage Sensor Amplifier with Disconnection Detection Function K7L-AT50D/-AT50D-S
FAQs
Some questions that are frequently asked about the K7L are given below. Use this information when selecting a model.
Can one K7L be used for detection in more
than one place?
Yes.
By using Terminal Blocks to connect Sensing Bands in parallel,
detection can be performed in more than place with only one K7L.
Note: When wiring, be sure not to exceed the maximum possible wir-
ing distances for both the wiring cable and the Sensing Band.
Exceeding these distances may lead to faulty operation. Con-
nect one Sensing Band to the each Terminal Block.
Can the K7L be used as a replacement for the
61F-GPN-V50 Water Leakage Detector?
Yes.
Because the surge withstand capability is different, however, do not
use in locations where it will be exposed to impulses and surges
such as outdoor roofs or pump panels. Also, items such as the power
supply voltage and the connection sockets are different. Confirm
these items before application.
Can a different terminal block (e.g. a
commercially available terminal block or a
terminal block constructed by the user) be
used instead of the one provided?
Yes.
When using another terminal block, however, be sure to check that
all the terminals are mutually isolated, and that there is no danger of
ground faults in wiring cables or Sensing Bands.
Can the K7L detect pure water?
Yes.
Even pure water, which has a resistance exceeding 10 MΩ⋅cm, can
nearly always be detected if the K7L is used at its maximum sensitiv-
ity. This is because impurities are mixed with the water when it is
leaked and the resistance drops.
Can the K7L detect oil?
In most cases, no.
If, however, it contains impurities such as metal powder, as is the
case with cutting oil and used engine oil, detection may be possible
(actual instances of detection have been observed). The user should
confirm whether the required kind of detection is possible before
application.
50 m max. 10 m max.
Terminal Blocks
K7L-AT50
Possible wiring distance
for wiring cable.
Possible wiring distance
for Sensing Band.
Pure water
Impurities in
the air
Impurities on
the drain pan Detection possible if sens-
ing range 3 (0 to 50 MΩ)
is selected using the DIP
switch.
In the interest of product improvement, specifications are subject to change without notice.
ALL DIMENSIONS SHOWN ARE IN MILLIMETERS.
To convert millimeters into inches, multiply by 0.03937. To convert grams into ounces, multiply by 0.03527.
Cat. No. F057-E1-01
