Running VOIP phones on UPS backup power
I’m looking at options to keep DSL-dependent internet phones (see my phone page) working at my cabin during the inevitable power blackouts. This is part of my emergency preparedness since the camp is in a cellular dead-zone. A criticism of VOIP phones is that you lose access during a power outage. However, while the old-style dial tone is more robust (low voltage power is in the phone lines), it is too simple to say VOIP must fail.
I have uninterruptible power supplies (UPS) running both my home desktop PC and the small Dell that is my cabin ‘server’. The UPS units each have a sealed lead acid battery for the uninterruptible power part, they can run the PCs and associated stuff for say 10 minutes. However, they are also there as high-end surge protectors and protection against brownouts. The cabin power is iffy and the UPS also protects the cabin system from those 10 second dropouts and their spiky aftershocks.
You can use UPS power to temporarily run the essential internet phone components. Those items are the OBI200 unit, router/modem and one phone base station for me. There was a proposal that service providers supply power backup for VOIP, but right now the user owns the problem. What I have done at home is configure the PC UPS to shut down early. This provide reserve power usable by the key VOIP dial tone components, after some replugging at the UPS.
I have bigger concerns about the internet phone dial tone at camp than about VOIP phone access at home, since the camp, in contrast to home, lacks cell service. After I wrote the initial Post I bought and tested a UPS (Back-UPS Connect BGE90M) designed for prolonged support of low demand systems (see *UPDATE* below). The BGE90M UPS is ready to take to my camp as a second UPS dedicated to VOIP phone essentials.
Trial runs using UPS to keep VOIP phones working
I have a Kill-a-Watt meter and plugged in an OBI200 internet interface, cordless-phone base unit, my home cable modem and a cheap router. This was at home as there is 16 inch of snow at my camp. The four items pulled a total of 9W. Load jumped to 16W when I switched to my powerful home wireless router that gets toasty to touch.
My home and camp UPS units from APC/Schneider Electric come with PC software called PowerChute that coordinates the behavior of the PC and UPS. The Software can specify when the PC shuts down – based on quality of power or the amount of backup time left in the UPS battery. As a trial, I reconfigured my home system: The home VOIP box and phone base station etc are plugged into the UPS, and the Powerchute software is now set up to shut down after 4 minutes of battery time, with more than 50% of PC support power left.
I ran a test where I unplugged the UPS from the wall socket and let the main PC shut down after 4 minutes under PowerChute control. Then I checked that I can get the UPS to turn back on without 110V household power after I unplugged the PC from the UPS. It has powered up the attached phone essentials to allow VOIP calls to my cell. I’m updating this section online via a laptop while the wireless router and cable modem run on the UPS battery power with no household current . The PC is rated at 500W, in the PowerChute screenshot you can see the system is pulling 200W (5 KW/day), so the remaining power in the battery will go much further supporting just the phone system, modem and router after the PC has shut down (easy math and an actual test run both come out at ~90 minutes).
Selecting a UPS for Internet Phone Gear
I have an APC BN600G UPS unit to gracefully shut down the PC when there is a Cabin power outage. PowerChute totally shuts down the PC and UPS which is why I will have to manually reconfigure things to get the router and phones working on the UPS during an outage. The newer BE600M1 UPS from APC apparently can shut down an attached PC while supporting low demand Tech (i.e. the internet phone setup) for 4+ hours on UPS battery power. You have to watch the alphabet soup in the model numbers and check the specs to buy the right UPS capability! I contacted API/Schneider electric and they say the low load stuff is controlled separate from PowerChute in this series of models. APC also has a small BGE90M unit they now sell specifically for phones & home networking gear, and a graphic shows data with run times over 4 hours at a 10 W power draw.
I think that eventually I will simply put the cabin internet phone essentials on a new UPS, separate from the one supporting the PC, to keep the phones working in any Cabin power outage.
** UPDATE** Back-UPS Connect BGE90M Purchase and Review: Works Great for Internet Phones
I bought and tested the Schneider Electric APC Back-UPS Connect BGE90M at the start of February. I used all three of the two-prong power outlets for the test after I allowed it to charge for a day. I didn’t put any load on the two USB outlets. My load items were a Motorola cable modem, an OBI 200 VOIP interface box and the base unit for a cordless phone. My Kill-a-Watt power meter was registering an 8W load. I was at home but this is about equivalent to my cabin phone system.
This BGE90M UPS ran for 5.25 hours unplugged before starting to emit warning beeps in this VOIP phone backup power test. During the test run I was using the internet normally (the PCs were not on this UPS) but did not use the VOIP phone setup to make any calls. That run time was better than you’d expect looking at the sample figures listed on the packaging box.
The run time for the APC Back-UPS Connect was impressive. It would get me through most of the power outages at my cabin. It’s a no-muss no fuss solution for keeping internet phones running. If there was a longer outage I can envisage switching between this and the PC UPS and charging the spent UPS with my small generator. That way I will avoid the risk of frying electronics with the generator current.
I could wish for another power outlet on the BGE90M UPS, so that I can run a router switch. I can make this happen with extension cords and adapters, and the router switch should demand minimal power. I can also see why APC would limit the options – it restricts likely demand, extending run time. APC probably was using similar logic when they put in the two pin sockets with no earthing – that mainly restricts folk to light demand power converters. This UPS does not run PowerChute ‘cos its not designed to support PCs.
I’d suggest using the secondary handsets, rather than the phone on the base station, if a family wants to make multiple internet phone calls with this set-up during a power outage. That way you don’t draw power to recharge phone batteries.
The TelCo end is still a question for keeping phones working
What I don’t know is how much power backup capacity the Phone company digital services have: The Frontier substation is only a quarter mile from my cabin which makes for a strong DSL link but that equipment shack is going to lose NYSEG 120V mains supply when I do. Or can Frontier power their digital systems with the traditional low voltage TelCo power used for low voltage lines? The Foscam C1 Camera inside the camp is powered by USB off the cabin PC and therefore from the UPS. I do know that it did keep sending a video-stream until the PC shut down the one time a I noticed a recorded cabin power outage. I had left a kitchen light on and you could see the nighttime recording drop to gray-scale as the room light quit. So the DSL did not fail as soon as cabin power went out (and possibly not at all).
A tree falling on the phone line?
Sorry this post doesn’t help with that. The season before last a 16″ diameter tree next to my driveway and power-lines decided to fall. Luckily it went in the direction away from the road bed and the lines.