SMC Networks C(D)RB1 50F Series Operation Manual page 15

(4) Be certain to connect the load before power is applied.
<2-wire type>
If the power is turned ON when an auto switch is not connected to a load, the auto switch will be
instantly damaged because of excess current (Short circuit).
In addition, when using a commercially available checker, etc., to perform an acceptance
inspection or check the operation of a 2-wire auto switch, be sure to confirm the wiring method
of the checker beforehand and make sure to connect the terminal with a built-in load (IN, etc.)
to the 0 V terminal. (Do not connect the power supply terminal and the ground terminal directly
when in a non-load state.)
(5) Do not allow short-circuit of loads.
<Reed>
If the power is turned ON with a load in a short circuit condition, auto switch will be instantly
damaged because of excess current flow into the switch.
<Solid state>
PNP output type auto switches do not have built-in short circuit prevention circuits.
If a load is short circuited, the auto switch will be instantly damaged as in the case of reed auto
switches.
Take special care to avoid reverse wiring with the brown power supply line and the black output
line on 3-wire type auto switches.
(6) Avoid incorrect wiring.
<Reed>
A 24 VDC auto switch with indicator light has polarity. The brown lead wire or terminal No.1 is
(+), and the blue lead wire or terminal No.2 is (-).
1) If connections are reversed, the auto switch will operate, but the light emitting diode will not
light up.
Also, take note that a current greater than that specified will damage the light emitting diode
and it will no longer operate.
Applicable models: D-93, A93V
<Solid state>
1) If connections are reversed on a 2-wire type auto switch, the auto switch will not be damaged
if protected by a protection circuit, but the auto switch will remain in an ON state. However, it
is still necessary to avoid reversed connections, since the auto switch could be damaged by a
load short circuit in this condition.
2) If connections are reversed (power supply line + and power supply line-) on a 3-wire type auto
switch, the auto switch will be protected by a protection circuit. However, if the power supply
line (+) is connected to the blue wire and the power supply line (-) is connected to the black
wire, the auto switch will be damaged.
Operation Environment
Warning
(1) Never use in an atmosphere with explosive gases.
Auto switches are not designed to prevent explosion. This may cause an explosion hazard.
Caution
(1) Do not use in an area where a magnetic field is generated.
Auto switches will malfunction or magnets inside rotary actuators will become demagnetized.
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