DA774-P-12VDC: 12V DC 8A Replacement power supply for DA774 Power Centre
A 12V 8A DC power supply unit. This unit is equipped with low-voltage monitoring clean contacts, mains-failure clean contacts and battery low-voltage disconnect (deep-discharge protection).
There are 10 load outputs available for use. All load outputs use automatic self-resetting fuses rated for continuous use and will allow a momentary inrush. Two of the outputs are designed to carry a higher load than the other eight. Please refer to product data sheet for more information.
This removable PSU allows replacement of DA774 power supplies without removing the wall-mounted enclosure.
Fire enable
All load outputs can be selected as either: (1) Fire alarm switched or (2) Continuously powered. Simply move the associated jumper link to either position 1 or 2 for each load output. Ideal for access control applications where door locks are required to de-power during a fire event regardless of mains power availability.
Individually fused outputs
Each output is individually fused with self-resetting fuses rated for continuous use to protect the power supply in the event of equipment or wiring failures.
In-built back EMF spike protection
Electromotive forces are caused by changing magnetic fields around inductors, often through self induction during inrush, inducing a voltage back into the circuit. Should devices such as magnetic locks and motors cause an EMF spike, these units are equipped with back EMF spike protection to prevent damage.
Mains failure monitoring contacts
In the event that mains power is not detected the Mains Fail
monitoring contacts will change-over. The volt free change-over contacts are ideal for switching equipment or providing signals to external systems.
Low-battery monitoring contacts
If the unit is equipped with a VRLA battery, the DA774 unit will automatically trickle charge it when mains power is available and seamlessly switch to this as a power source when mains power is not available. In the event of the battery is running low on capacity the Low Vol
monitoring contacts will change-over, ideal for signalling systems or switching other equipment that the system is about to de-power.
Deep discharge protection
Completely discharging a battery or deep cycles can cause significant damage to batteries and reduce their future performance. To prevent this type of damage all DA774 Power centres will automatically disconnect a connected battery that has been depleted of useful capacity to protect it from damage. When mains power is restored, the unit will automatically re-connect and re-charge it.
Power on LED status indication
The power supply unit has a green LED to give visual indication of if power is available.
Individual-output LED status indication
Each output of the Power Centre has an LED indicator to visually show an engineer the current power status of each output.
12V DC high reliability and efficiency switched-mode power supply
Switched-mode power supplies are much more energy efficient than coiled transformers that continuously produce magnetic fields for another coil to convert to an alternative power level. Switched-mode power supplies have power storage that feeds output filtering circuits at much lower voltages to that of the mains-input which is switched on and off at high frequency to maintain the power in the supply. This method wastes less energy making a much more energy efficient power supply.
Battery back-up
Integrated UPS function supports VRLA batteries up to 17Ah. When mains power is available this unit will charge and maintain the battery. When mains power is not available, this unit will seamlessly switch to the battery for power input maintaining power to the outputs. When power is restored, the unit will automatically seamlessly switch back to mains power and re-charge the battery.
13.7V Battery terminals are suitable for VRLA battery configurations of 12V up to a capacity of 17Ah.