VL-T (AZ84)
3. Construction of logic circuits
(1) AND circuit
(2) OR circuit
Load R will operate only when both A
and B touch limit switches are in detect-
ing condition.
Load R will operate when either A or B
touch limit switch is in detecting condi-
tion.
24V
+
24V
+
R
3
2
1
3
2
1
R
A
B
3
2
1
3
2
1
A
B
CAUTIONS
1. Antenna
1) Material of antenna
2) Distance between antenna and
ground
At least 100 mm 3.937inch distance is
required between antenna and earth.
3) Distance between antennas used in
parallel
Any kind of material is usable if it is con-
ductive. Protect it from oil, dirt and rust
which may lead to non-conductivity.
More than 50 mm 1.969inch distance is
required when two or more switches are
used in parallel. Also, leave a distance of
at least 20 mm between the VL-T mini
touch limit switch bodies.
more than 50 mm 1.969inch
more than 100 mm 3.937inch
more than 50 mm 1.969inch
4) Limitation of free attachement antenna
Any kind of shape is usable. If it is too
large, switches may malfunction. Total
area should be within 500 mm2 and max-
imum length should be 300 mm
11.811inch.
5) Mounting of free attachment antenna
Fasten it tightly using attached washers.
6) Limitation of free attachment antenna
(in the case of more than one antenna)
Total length should be less than 300 mm
11.811inch for line materials (dia. <2 mm
.079inch) and total area should be less
than 500 mm2 for metal plates.
Flat washer
Lock washer
less than
500mm2
less than
1
4 mm .157inch Hex. nut
Touch limit
less than 500mm2
300mm
Lead
wire
11.811inch
less than 300mm
11.811inch
4.2 dia.
holes
4 mm .157inch Hex. nut
Flat washer
Antenna
2
1
2
<300mm 11.811 inch
+
Lead diamater
less than 2 mm .079inch
2. Ambient conditions
1) Avoid using VL-T switches in the fol-
lowing conditions:
• In corrosive gases.
6) Surge absorbing elements are recom-
mended to protect internal circuit when
external surge voltage exceeds 500 V [at
(1 ꢀ 40) µs single polarity all wave
voltage].
7) When heavy static electric runs in an
antenna, the internal circuit might be bro-
ken. Avoid using at the case of more
than 3 kV.
8) When VL-T is operated by dry cells or
batteries, DC power source with B
polarity grounded by chassis, ground B
or v polarity of power source.
9) It is not necessary to ground main
units.
3. Sensitivity adjustment
1) Use a v screw driver and turn the
sensitivity adjustment knob to the right
(H) for higher sensitivity (Max. 20 pF)
and to the left (L) for lower sensitivity
(50 pF).
• In flammable or explosive atmospheres
2) Use within an operating voltage of 10
to 30 V (ripple factor: max. 10%)
3) Use within an ambient temperature of
–20 to +60°C –4 to +140°F.
4) When VL-T detects water (conductor),
its antenna can be immersed in water.
Since its body is not of water tight con-
struction, avoid using it in locations
where water or oil can splash over it or
dust is heavily accumulated.
Max. 20 pF to min. 50 pF sensitivity
adjustment is possible.
2) When you set the sensitivity, you must
set it a little higher than the detection
level and provide a sensitivity allowance.
4. Refer to temperature and voltage
Characteristics in DATA in page 69 when
temperature and voltage fluctuate
extremely. Testing under a practical con-
dition is recommended.
5) Avoid installing lead wires or antenna
of VL-T in parallel with power wire.
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