Connecting Analog phones to PSTN during power failure

[pc]

Hi guys,

I have a scenario hoping someone may have a solution.

we need to replace an old PBX. The cuurent PBX is connecting to an emergency response system which has analog handsets that can communicate with other handsets on the system but can directly connect to telephone company PSTN lines during power failure.

I know about the Cisco's emergency bypass configuration with EM-HDA-6FXO but i will need way more than the 2 lines provided by EM-HDA-6FXO. Is there a device that will allow me to connect the analog handsets to the telephone company provided PSTN analog lines and a VG-224 simultaneously? during normal operation, the analog handsets acts just like a normal analog handset hooked up to the analog port on VG-224. It will connect to the PSTN directly when the VG-224 loses power.

Your help is greatly appreciated.

Thanks!

[paolo bevilacqua]

You can use an A/B switch for that, can be bought at a telecom supply shop.

However in most cases, providing good UPS is enough.

[pc]

Thanks for the reply Paolo.

Unfortunately this is a factory in a remote area and power outage can often last for 24 hrs. So i need an automate the solution. I remember when i was a kid,  my house had multiple phones put only one telephone line. we had a device from radio shack that would allow one phone to be active while other phones could not get a dial tone when the other phone was active. May be there is a such a similar device for this scenario.

Thanks for your input!

[Rob Huffman · Accepted solution]

Hi there,

In addition to the great tips from my friend Paolo (+5 "P")

You will want to use a product like the one linked below where you connect

the lines from the VG224 and the PSTN circuits and they transfer across in the

event of a power fail.

http://www.dees.com/html/154_8_154A_8.html

Cheers!

Rob

"Everything is broken" - Bob Dylan

[pc]

Great answer as always Rob. Exactly what i m looking for!

[Zac Speck]

Were you able to get this to work using the DEES 154/154A? I have a customer using those unit on the old phone system and we are moving to Cisco. I get the main concept in how the unit works but not sure how it will detect a power failure on the Cisco equipment.

Any help would be appreciated.