Hi Mike, Here are my answers to your questions:
"First, I thought you were in the design stage. Not all locks are fail-secure. If you use magnetic locks they are not fail secure. In the case of ELR and electric strikes, the way to insure they remain locked (and what EAC does to insure it) is to remove power. The eac system will do this on command, such as the lock down command or "all secure" in most systems. As for the time schedule being dependent on the network, if it is then it is host bound. Host bound systems are the least dependable available. If you are host bound, then woefully the hardwired option is the best and hopefully you only have one building with a few devices."
There were EAC systems that were designed by our company or those designed by others that have already been put into place that have the above mentioned design. And yes, the most common system we sell is the host bound. That is why I was thinking of going the hardwired way for future designs. And you are correct about the mag locks. We do not use those often in our deployment. But in the case that we do, I believe we leave the existing vertical rod devices in. This is the exception where the mechanical locking mechanism is not affected.
"If doors have electrified strikes and/or exit device with ELR they are secure no matter what the system failure. The only exception would be a strike that was wired to be fail safe........very rare. In 34 years of locking doors and designing ways to lock doors I have only seen one instance where a fail safe strike was required and that was in a rather obscure government facility."
Yes, they are all fail-secure. However, with the host-bound system, the doors will only secure if they lose power, the EAC panel goes down, or they are told to lock down. If the EAC panel is up and running and network connectivity is lost, there is no way to lock them other than killing power or a hardwired button. For example, if the strike is energized and stays energized, no matter what I do to the door lock (mortise, cylindrical, or rim exit device), I cannot secure the door because the strike still allow the door to be opened. So only when power is lost to the strike and/or the panel, will the door lock again.
"Why can't you use the keys to lock the doors? You are saying you have locking devices that the keys will unlock but cannot be locked by keys? Sorry if I seem dumbfounded but that's what I am.
Why would you disable the mechanical means? In the case of electric strikes you can leave the locks in a secure state always. Exit devices with ELR are also un-dogged and thus in a secure state always. Only in the case of mag locks would you leave the mechanical lock unlocked in a normal state and be required to go to the door with a key if the power to the locks was lost."
I will use the strike as an example. The locks are always secured, but the strike is controlled by the EAC. Therefore, the door opening is now controlled by EAC. So when the strike is energized, the only way to secure the opening is by killing power to the strike. Using a key will not secure the opening because it only locks and unlocks the door lock, but not the strike. Does this make sense?
I am not disbaling the mechanical means, I am leaving it in-tact. However, due to the nature of the electrification, mechanical means to lock a door is substituted by the electrification. Hope this helps.