C•CURE® 800/8000 9.4 apC/8X Technical Manual - Tyco Security ...

Voltage Requirements
Voltage Requirements
The apC/8X supplies 12 volts at its connectors; however, the amount of
power that actually reaches each RM board in a chain is less than 12 volts.
• The RM-4 requires at least 7.5 volts to operate properly.
• The RM-4E requires at least 11 volts to operate properly.
The total voltage is lowered by each reader and by the resistance of the wire.
Whether the RM board chain needs a local power supply depends on all the
following factors:
• Number of devices on the bus
• Current draw of each device
• Distance between the devices in the chain
• Distance between the devices and the apC/8X
• Wire gauge used to connect the readers and the apC/8X
Refer to sections that follow to calculate the power in a chain. Be sure you
read and understand the instructions and examples in each section before
beginning to calculate the maximum wiring lengths for your application.
D-2 apC/8X Installation and Configuration Guide