Wiring
Operating Manual PSEN sg2c-5CCLLE
1004172-EN-02
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5
Wiring
5.1
Notes on cable run
The maximum cable run depends on the voltage drop in the supply voltage conductors for
solenoid operation. The level of voltage drop is determined by the
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cable resistance of the cables
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solenoid current of the solenoid
If the voltage drop in the supply voltage conductors becomes too high, the voltage for
solenoid operation can permanently be set to the upper tolerance range (see Technical de-
tails).
The max. cable diameter is 10 mm.
Example:
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Connecting 3 safety switches in series
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Total cable run: 25 m
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Conductor cross section: 0.5 mm
2
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Solenoid current per solenoid: 1.5 A
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Voltage for solenoid operation: 24 V
4
U~0.05*10*1.5*4.5~3.4 V
U~0.05*5*1.5*3~1.1 V
U~0.05*10*1.5*1.5~1.5 V
U~cable specific impedence*cable length*cable factor*current
Cable impedence(2x0.25 mm²)
=0.05 Ohm/meter
25 m
0
The voltage drop over all the safety switches is 6 V. This means, there are only 18.0 V at
the terminals of the last solenoid. The solenoid is no longer operated reliably. If the voltage
for operating the solenoid is increased by the max. permitted tolerance to 26.4, there are
still 20.4 V at the terminals of the last solenoid. The solenoid switches reliably.
