SMC Networks C(D)RB1 50F Series Operation Manual page 13

(3) Do not use a load that generates surge voltage.
If a surge voltage is generated, discharge may be generated at the contact, possibly reducing the
product life.
<Reed>
Use an auto switch with built-in contact protection circuit or use a contact protection box.
<Solid state>
Use a built-in surge absorbing element type device.
(4) Take precautions when multiple rotary actuator are used close together.
When multiple auto switch rotary actuator are used in close proximity, magnetic field interference
may cause the auto switches to malfunction. Maintain a minimum separation of 40mm between
rotary actuator.
The auto switches may malfunction due to the interference from the magnetic fields.
Use of a magnetic screen plate (MU-S025) or commercially available magnetic screening tape can
reduce the interference of magnetic force.
(5) Pay attention to the internal voltage drop of the auto switch.
<Reed>
1) Auto switch with an indicator light
● If auto switches are connected in series as shown below, take note that there will be a large
voltage drop because of internal resistance in the LED. (Refer to the internal voltage drop in the
auto switch specifications.)
[The voltage drop will be "n" times larger when "n" auto switches are connected.]
Even though an auto switch operates normally, the load may not operate.
● In the same way, when operating under a specified voltage, although an auto switch may operate
normally, the load may not operate. Therefore, the formula below should be satisfied after
confirming the minimum operating voltage of the load.
2) If the internal resistance of a light emitting diode causes a problem, select an auto switch without
an indicator light.
<Solid state>
Generally, the internal voltage drop of the solid state auto switch is larger than that of the reed auto
switch. When the auto switches ("n" pcs.) are connected in series, the voltage drop is multiplied by
"n". In this case, even if the auto switches operate correctly, the loads may not operate. Additionally,
note that the 12 VDC relay does not apply to the auto switch.
(6) Pay attention to leakage current.
<Solid state / 2-wire type>
Current (leakage current) flows to the load to operate the internal circuit even when in the OFF
state.
Operating current of load (OFF condition)
If the criteria given in the above formula are not met, it will not reset correctly (stays ON). Use a
3-wire switch if this specification will not be satisfied.
Moreover, leakage current flow to the load will be "n" times larger when "n" auto switches are
connected in parallel.
(7) Ensure sufficient clearance for maintenance activities.
When designing an application, be certain to allow sufficient clearance for maintenance.
Supply Internal voltage
voltage drop of auto switch
Load
負荷
Minimum operating
>
voltage of load
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Leakage current
12