atcomsystems.ca/forum Forums Wiring - Telecom Carriers - Trunks & Services Security, Alarms and Paging Security Phones

I am putting a new phone system in an apartment building. There are 18 security/courtesy phones in the parking garage and othe public areas. These look like plain old-fashioned Western Electric wall phones, except there is no dial, just a round plastic insert where the dial usually goes. When I picked one up there was no dial tone or pulse. After a few seconds, the front desk just answered. I don't remember if there was a ringback sound first or not.

What kind of phone system can handle this kind of arrangement. Also, how many of these security phones can I put on one extension circuit. Right now it seems that all 18 security phones are on one extension circuit.

You can use any PBX that has a "hotline" feature (or some such nomenclature). Avaya Magix and IPO will do this, and I'm quite sure other brands will as well. Usually all that's involved is to flag the guest/no-dial phones as hotline phones, then define the target number in a speed dial list.

Can the front desk call the individual 18 security stations? Or is there only one published extension for all phones? Does anyone ever call security, or are all calls one-way from the security stations to the front desk? Ask those kind of questions to determine whether these are individual extensions or not. The reason you care, partially, has to do with REN (Ringer Equivalency Number). REN is a way to measure "how many phones can a single extension's port ring simultaneously"?

Let's say you implement a Magix with an 016T/R analog board and plan to use just one port and daisy-chain all 18 extensions. Note that a single Magix analog port has a REN rating of 4.0. Let's also say that the security phones are a modern flavor and have a REN of 0.1 (that number is listed on the bottom of the phone).

Next comes the easy math. 18 phones x 0.1 REN = 1.8 total REN. Fortunately, the analog ports we've chosen will support a total REN of 4.0. Were these older phones from the 1930's, an individual phone's REN might be 1.0, which would total 18 REN. Because that number is higher than what our equipment is rated for, it's likely that calls to those 18 stations will not ring.

Is this the same site as the "elevator phones" in the previous thread?? If it is, then it seems like you are contemplating replacing an older Rolm, Mitel, Toshiba or some other large PBX. You should also be looking for any Viking equipment (line share boxes, phones, ringdown circuits etc.)
Best to find out exactly how everything is working before you start ripping things out.

The security phones are different than the elevator phones in my other topic. The security phones look like standard 50 year old Western Electric wall phones with a blank plate where the dial normally goes.

I like the suggestion to check the phone room very carefully. So is Viking a brand name I would see on a ringdown box? Would it be on the phones too?