That would be the wrong way to do it. Use a power supply with a fire alarm interface and have it trigger the locks to open. The fire alarm relay when activated will cut power to the selected outputs. Every power supply manufacturer makes power supplies with a FAI like Altronix or Securitron. We have used hundreds of the below:
You will need to have a fire relay from the fire panel within 3-5' of the access panel/pwr supply. As the above mentioned tie the FACP interface off of the ACM8 board (if you go with the Altronix AL400ACM power supply) to the fire relay either NC or NO.
You can actually do it both ways, powered or non powered. But powered ensures integrety of system in event of failure. must follow msds listed diagrams
depends on application
The loop thru is a non power function , it just opens the circuit on alarm , and it depends on the type of FACP your using. and the intended application .
If Ul then you must adhere to msds and listed applications no matter what .
Each Manufacturer has their own concept of doing the same thing.
So Follow the listed MSDS on the Facp, Devices, and Code books .NEC 70,70e, NFPA 72,80,101
If your doing this type of work you should already own the codes.
should have no problems if tested 100%
If there is an AHJ that will be inspecting either this or the fire system, you must use a purpose-built power supply with a fire alarm disconnect.
My personal favorite (not affiliated with them) are LifeSafetyPower power supplies. You mention 3 amps above, and while that may be sufficient, that seems relatively low unless you're using all extremely low-power devices. Additionally, since technically your locks need to be fail-safe, that means they will all be powered, so I would increase to a 12A/12VDC power supply if it were me. Something like this would work perfectly: http://www.lifesafetypower.com/docs/ds_fpo150-c8e1.pdf
kindly check the attachment and advise me which would be the best way to do the Fire Panel integration with Door Access . Plan A decided to cut DC power Source & Plan B decided to cut AC power source.
I guess you haven't read any of the above comments. Both plans are absolutely wrong. It's not that complicated if you use a power supply with a fire alarm interface. One relay from the fire alarm and it does what you want correctly. Don't take this the wrong way but maybe you should call in a more experienced installer to help you out with this?