N93-597-00 Issue 1
Page 12 of 17 © Protec Fire Detection PLC 2014
6.8 Connecting the 24V output wiring
When connecting wiring from the fire alarm equipment to any other equipment, care must be taken
to avoid subjecting the fire alarm equipment to any hazardous voltages. This is normally achieved
by only connecting SELV circuits to the equipment, or by using optical or galvanic isolation.
The 24V output from the power supply are fed from the terminals marked '+
24’ and ‘0V' on the main PCB
(TB2).
6.9 Connecting the global fault output wiring
Volt free global fault contacts are provided to allow optional connection to ancillary systems.
These connections are found on the PCB and are marked N/O, N/C and COM (TB4).
Under 'no fault' conditions the COM and N/C contacts are short circuit, and change to open circuit when the
PSU has detected a fault (including being completely depowered).