power for door mags

[nietzj]

I have been asked to rewire some door hold open magnets so they can remotely be closed, this would in no way interfere with the basic fire alarm function. The issue is in order to do this the drawings show me feeding power to the door mags through a card access system not through the FACP.... Does the power for the door mags have to originate from the FACP?

 

[kwired]

If the doors are required for preventing the spread of smoke/fire then they must close when the fire alarm is active.

If they are not for that purpose you likely can do just about anything you want with them.

 

[nietzj]

The doors must close in the event of a fire. The set up is the mags are de-energized at night allowing the doors to close, once they close and lock they can now be opened with card access from the outside, to exit from inside you have exiting hardware on the door. This issue is can I use the 24v from the card access to hold open the doors or must it come fro the FACP power supply?

 

[luckylerado]

Does the power for the door mags have to originate from the FACP?

No but the circuit does need to be monitored / supervised IAW 12.6 of NFPA 72

 

[kwired]

Whatever you do the doors must still close when the FA is active. If you want to disable the door holder mags you would still power them from the FA, and put a switching device in series with the line if you want the card reader to disable the mag at any time, that way regardless of what state the card reader is in the FA still closes the door when needed.

Magnetic holders aren't necessarily powered from the FA but do have a relay in their circuitry that is controlled by the FA.

 

[Strathead]

The doors must close in the event of a fire. The set up is the mags are de-energized at night allowing the doors to close, once they close and lock they can now be opened with card access from the outside, to exit from inside you have exiting hardware on the door. This issue is can I use the 24v from the card access to hold open the doors or must it come fro the FACP power supply?

It is very common for the power to originate in the card access system. There is also a method where the doors are held with 120V and they go through a fire alarm relay to deenergize. Most card access systems I am aware of have terminal inputs for fire alarm signals. Usually the door closing part is fail safe, meaning that if the panel goes in to alarm, the relays will mechanically open and power goes off.

 

[gadfly56]

You have two (2) things going on here. You have fire and/or smoke doors which need to release on fire alarm. These doors are also part of an access control system and that needs to be disabled on fire alarm. I assume you have an intelligent panel and you can put addressable relays in the field.

You will have one relay that interrupts power to the door holders (normally closed).

You will have a second relay that interrupts power to the security mag locks (normally closed).

When the fire alarm system is activated both relays will open, closing the fire/smoke doors and disabling the security locks.

Normally you won't provide power from the FACP because door holders/locks are power hogs, relatively speaking. You can provide almost any type you want, 24 vac/vdc, 120 ac etc as all relays from any manufacturer will be rated for either, and while the power draw is high relative to the battery capacity of the FACP, it's well below the max for said relays.

 

[ssgobeli]

Independent Power Supplies for Door Locks

Independent Power Supplies for Door Locks

Using other power supplies such as an access system is allowed. Check NFPA 72 (2010) 21.8 and 21.9.