relay information needed PLEASE!!!!

I've purchased a phone system that's capable of releasing typical magnetic locks remotely from any extension phone. An accessory called "external feature module" is responsible for deacivating a mag lock via a terminal block controlled by any phone. The circut is normally closed, when opened the power to the mag lock's rendered deactivated. My mag lock has to be deactivated by closing two leads. For some reason the manufacturer doesn't want the lock to be unpowered in order to gain egress. Here's my question. The telephone manufacturer tells me I need a "normally open" relay that serves a nomally open circut for my type of mag lock. If I select a 12 VDC (INPUT VOLTAGE) SPDT (CONTACT TYPE)

10 AMPS (LOAD RATING @240 VAC), (POWER COMSUMPTION) 115 mA, 5 PIN RELAY

- spade terminal relay. OR DO I NEED AN ENCLOSED POWER RELAY DPST-NO 25 AMPS 12 VDC 158 mA (STANDARD WITH DC INPUT VOLTAGE) CAN YOU PEOPLE HELP ME MAKE THIS FLY?

Forgive me if I get this wrong. Are you talking about a door latch which is held closed by magnetic attraction such as

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If so, then these latches must be permanently powered in order for the door to remain locked. Without knowing the details of your telephone system my guess is that it only provides a contact closure when you want to open a door latch remotely. This is exactly the opposite of what you want if you are using a Magnalatch.

If the door latch interface on your telephone system has a form C changeover contact as the latch output then you could wire the Magnalatch via the normally closed contact instead of the normally open contact. I suspect that your system doesn't have a changeover contact but only has a single normally open contact instead. You can add a separate relay which does have a changeover contact, so that the door latch is wired via the normally made contact of this additional relay. When the phone system sends a signal to operate the relay momentarily the normally made contact will open and the Magnalatch will be released and the door can be opened. Of course, this relay has to be mounted somewhere close to the phone system and it must have a supply voltage suitable for the relay characteristics. It would be preferable if it could be mounted inside the phone system and utilise the dc supply which is provided.

You would be aware that unless you have an uninteruptible power supply to power the Magnalatch then during power outages the door will be able to be opened at any time?