Troubleshooting Power Supplies for Access Control Systems

troubleshooting power supplies for access control systems

  • PS902: 2 amps
  • PS904: 4 amps
  • PS906: 6 amps

Note: The Von Duprin PS914 and 900-2RS are available for use with electrified exit devices.

In addition, Schlage offers several different option boards for the PS-900 series.

  • Emergency Interface Relay (FA) – Must be installed on distribution boards
  • Battery Backup
  • 2 relay QEL panic device control board


When interfacing with a fire alarm system where the system’s auxiliary relay cannot handle the full current potential of the power supply, or when monitoring power systems for AC failure or DC battery failure, the BPSM linear power supply offers additional protection.

During battery operation, if voltage drops below 10.4VDC for 12VDC (20.8VDC for 24VDC) the battery will automatically disconnect to prevent possible damage to the system.


  • 8 polyswitch (PTC) 2A output breakers
  • Slide switches connect or disconnect load from power
  • LED indication (AC and DC) showing power supply status
  • Emergency low current fire release terminals
  • AC status output terminals, SPDT, 3 Amp

Sealed lead acid-gel battery charging capability (battery not included)

RCI PDM-4, PDM-4C, PDM-8 and PDM-8C

The RCI PDM-4, PDM-4C, PDM-8 and PDM-8C boards distribute a single low voltage AC or DC source into 4 or 8 outputs. The output voltage and total current available is determined by the input supply.

When installed into a power supply, servicing time can be greatly reduced by the output indicator LEDs. If an output fuse is blown or PTC is tripped, the accompanying LED will be off, simply identifying the device connected to this output will allow for a problem to be quickly corrected. In addition to short circuit protection, the input terminals also have a surge protector that can absorb a 1500Watt spike or surge to protect connected devices


  • Converts a single output to 4 or 8 separately protected outputs
  • Available with fuses (PDM-4 or 8) or PTC Circuit Breakers (PDM-4C or 8C)
  • Separate Green power indicator LED for each output
  • Power switch to shut off all devices for servicing on PDM-4 and 4C only
  • Circuit breakers up to 1.5A provide Class II power limiting


These units convert one 12 to 24 volt AC or DC input into eight independently controlled fused or PTC protected outputs. These power outputs can be converted to dry form “C” contacts (ACM8 & ACM8E only).

Outputs are activated by an open collector sink or normally open (NO) dry trigger input from an Access Control System, Card Reader, Keypad, Push Button, PIR, etc.

The units will route power to a variety of access control hardware devices including Mag Locks, Electric Strikes, Magnetic Door Holders, etc. Outputs will operate in both Fail-Safe and/or Fail-Secure modes.

Units are designed to be powered by one common power source which will provide power for both the board operation and locking devices, or two totally independent power sources, one providing power for board operation and the other for lock / accessory power.

The FACP Interface enables Emergency Egress, Alarm Monitoring, or may be used to trigger other auxiliary devices. The fire alarm disconnect feature is individually selectable for any or all of the eight outputs.


To read additional Locksmith Ledger articles on power supplies for access control applications, visit

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