User manual

20 BC615 Installation and User Manual
Central power supply
If central power supply is used, precautions should taken against
voltage drop. Dimension the power supply equipment and cables so
that the voltage at the last door is not below the lock or reader’s
tolerance. A 24V electric locking device for example, has a tolerance of
+ -15% which is equivalent to 20,4V.
One way of reducing unnecessary power loss is to place the power
supply equipment somewhere in the middle of the circuit. Thus, the
load will be equal on each side of the power supply. If the distances or
the load are too great, multiple power supply units will be required.
Local reader power supply
Whenever one or several readers are connected to a local power supply,
remember to join the negative wires (0 volt) to avoid potential
differences. See example below.
CR1
BC615 BC615 BC615
+
___
++
CR1
CR1