3R63.055 - Lock Interface Unit



The Lock Interface Unit (LIU) is a PCB which is intended to be DIN rail mounted as supplied, that allows you to control and monitor the Chubb 3R63 Pass and 4L78 Cell Locks.

One of the PCB's is required per lock.

Product Item Codes

3R63/055/01/S - Lock Interface Unit (Pre 2014 installations)

3R63/055/02/S - Lock Interface Unit With Relays (Post 2014 installations)


The PCB's can be fitted singularly local to the door in a junction box or header, or for larger systems in a centrally located cabinet where a number of locks may be installed using a shared power supply.
There are 3 terminal blocks which allow the wiring from the Power Supply/Door Position Switch and the Control System, to interface with the Lock.
Using a rotary switch mounted on the PCB, the lock can be configured to either

  1. Auto-relock (If bolt withdrawn)
  2. Auto-relock (after specified time*, no bolt withdrawal necessary)
  3. Require an external input to lock.

* Relock time is selectable in 5s intervals up to 1 minute.

Interlocks can also be achieved by connecting together the required PCB's


The PCB has terminations to monitor the following;

  • Mechanical Lock (ILU)
    The ILU is connected directly from the lock to the monitoring terminal block TB2, there is no digital input to the processor. This is a changeover contact so either state can be monitored/displayed, mechanically locked or unlocked.
  • Electric Locking Unit (ELU)
    The ELU is the double solenoid unit within the lock, for which the PCB provides the pulse sequence to unlock. This then frees the bolt to allow withdrawal via handle operation. The sequence is;
    • Solenoid A energized, 100mS Delay.
    • Solenoid B energized, 400mS Delay.
    • Solenoid A de-energized, 100mS Delay.
    • Solenoid B de-energized.
  • Bolt Position
    This is also an open drain output which gives 0V when the bolt is extended. As soon as the bolt is withdrawn and the locks micro-switch activates this output goes to 24V.
  • Tamper Loop
    This is similar to the ILU in that it is directly connected from the lock to the monitoring terminal block TB2. There is no input to the PCB's processor.
  • Door Position
    An external door switch (i.e magnetic) is required to signal to the PCB that the door is in frame. This is used for auto relock operation.