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A3D
A3D
28
Precautions
Refer to the Common Precautions for Pushbutton Switches on
page 14.
Correct Use
Mounting
Always make sure that the power is turned OFF before mounting,
removing, or wiring the Switch, or performing maintenance.
Do not tighten the mounting ring excessively using pliers or a similar
tool. Excessive tightening may damage the mounting ring. (Tighten-
ing torque: 0.20 to 0.29 N
m)
Wiring
When wiring, use wires of a size appropriate for the applied voltage
and carry current. Perform soldering correctly under the conditions
given below. Using the Switch with the wires soldered incorrectly
may cause the terminals to become abnormally hot and cause a fire.
1. Hand soldering: At 30 W within 5 seconds.
2. Dip soldering: At 240
°C within 3 seconds.
Wait for one minute after soldering before exerting any external
force on the solder.
Use a non-corrosive rosin liquid for the flux.
Perform wiring so that the wire sheaths do not come into contact
with the Switch. If this is unavoidable, use wires that can withstand
temperatures of 100
°C min.
After wiring to the Switch has been completed, ensure an appropri-
ate insulation distance.
LED
The polarity of the LED is indicated on the back of the Switch. Wire
the LED correctly according to the polarity.
The built-in LED does not have a limiting resistor. Connect a limiting
resistor.
Make sure that the limiting resistor satisfies the characteristics of
the built-in LED. The forward current of the built-in LED must be
8 mA minimum.
The resistance can be calculated by using the following expression.
R = (E –VF)/IF ()
E:
Operating voltage (V)
VF: LED forward voltage (V)
IF:
LED forward current (A)
Recommended Values for Limiting Resistance
Voltage
Red
Yellow
(White)
Green
5 VDC
165
140
145
12 VDC
515
490
495
24 VDC
1,100
1,090
1,095
Note:
The above values are calculated values that can be used as
reference.
Calculation Example for Limiting Resistance
Conditions: Red LED with an IF of 20 mA at 24 V and a Ta of 25°C.
From the red LED characteristic given previously, VF will be 1.7 V
when IF is 20 mA. Therefore, R = (24 V – 1.7 V)/0.02 A = 1,100 .
Thus the recommended resistance is 1.1 k
at 1 W (2 x IF2R). (see
note)
Note:
A factor of 2 is applied because the permissible wattage of
the resistor must be twice as large as the required wattage.
Operating Environment
Ensure that dust, metal powder, or oil do not enter the interior of the
Switch.
Using Microloads
Using a standard load switch for opening and closing a microload
circuit may cause wear on the contacts. Use the switch within the
operating range. (Refer to the diagram below.) Even when using mi-
croload models within the operating range shown below, if inrush
current occurs when the contact is opened or closed, it may cause
the contact surface to become rough, and so decrease life expec-
tancy. Therefore, insert a contact protection circuit where neces-
sary. The minimum applicable load is the N-level reference value.
This value indicates the malfunction reference level for the reliability
level of 60% (
λ 60) (conforming to JIS C5003). The equation, λ 60 =
0.5 x 10–4/times indicates that the estimated malfunction rate is less
than 1/2,000,000 with a reliability level of 60%.
Standard
load area
Microload
area
Invalid
area
V
oltage
(V)
Current (mA)
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. A031-E1-05