User Manual

K7L-U@/-UD@@
16
Disconnection Detection Function (K7L-UD/UDB/UDP/UDPB only)
Operation While 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
signals that are output are interrupted by the Terminator and the
core of the Sensing Band will form 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
terminal 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 While Monitoring for Disconnection
• Output of disconnection detection signals starts within 2 s after
power is supplied to the K7L and is repeated at approximately 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
disconnection 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 disconnection.
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, it will determine that a disconnection
has occurred. The output indicator will flash, and the disconnection
output will turn ON/OFF.
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.
2-1. Disconnection occurs between the K7L and the place where liquid is leaked.
2-2. 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.
Surges
234
423
5
6
7
8
4
3
2
1
K7L
2.5 VAC (3.75 Hz)
Signals interrupted by
Terminator.
234
423
5
6
7
8
4
3
2
1
K7L
234
423
5
6
7
8
4
3
2
1
K7L
10 VDC max., 200 ms
Disconnection detection signals
are not interrupted by the
Terminator and return to the K7L.
234
423
5
6
7
8
4
3
2
1
K7L
Signals are interrupted where the
disconnection occurred.
234
423
5
6
7
8
4
3
2
1
K7L
When using shield wire
61F-03B
Induced lightening
9
53
11
71
43
61
9
8
11
7
Ground Ground
61F-03B
Electrode connection
terminals
61F-04B
Electrode connection
terminals
Use in conjunction with a 61F-03B/04B Surge Suppressor Unit in environments exposed to surges.
Install the Surge Suppressor Unit near the K7L. The surge suppression may not be sufficient if the Surge Suppressor Unit is installed near the
Sensing Band.