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DylanMitchel
join:2011-02-27

DylanMitchel

Member

Arris TM3402 EMTA TB130 DC Output UPS Battery Back up

Cox provided a battery back up for my TM3402 for no charge as a courtsey. For the $80 or so they'd normally charge I'd likely get a UPS vs the TB130 so I could keep the internet and phone working. I have a few questions about how it works:

So this is basically a dedicated UPS for the TM3402?

When testing by unplugging from AC power only the phone light stayed lit, does this only power the modem for phone and not the internet as well?

If there's a localized outage and the node is still up or running off back up power does this mean the TB130 will only provide phone service and not supply internet?

If I wanted to have internet during a localized outage I'd need a UPS and to plug the Touchstone into it with the regular power cord?

I'm happy to have a promised 8 hours of use and 24-hour standby for the phone but a little-disappointed internet will go down. It's understandable that they prioritize the phone to get the backup time and that's why I'd prefer a set up with a separate phone/ voice and data/ internet modem. But it's working very well and there's no rental fee since I have Cox phone and I could always get a UPS for the modem and my router.
Maltz
join:2011-01-08
Fayetteville, AR
Calix 844G
Netgate SG-2100
Ubiquiti U6-LR

1 recommendation

Maltz

Member

Yes, that battery only powers phone. I've got all my network gear on UPS, so the modem, router, etc never goes down, but YMMV on how long even the node keeps your internet up if power to the node is also down. In my experience, it's only about 5-10 minutes. After that, even the node itself is phone-only.

Then again, if power is out to your house and not the node, then s UPS will keep your internet up at long as the UPS runs. How likely that scenario is depends on lots of factors, though.
DylanMitchel
join:2011-02-27

DylanMitchel

Member

Thanks. Depending on who you talk to the node has no backup, some battery back up, or a generator back up. A long way from copper lines powered by the phone company in terms of reliability.
Power outages are rare here and when they occur Verizon can be more reliable than Cox phone so I'm guessing the node doesn't have much if any backup power and a UPS of any kind is won't help if the nodes out.
Fubar
join:2015-01-27
Phoenix, AZ

1 recommendation

Fubar

Member

said by DylanMitchel:

Thanks. Depending on who you talk to the node has no backup, some battery back up, or a generator back up. A long way from copper lines powered by the phone company in terms of reliability.
Power outages are rare here and when they occur Verizon can be more reliable than Cox phone so I'm guessing the node doesn't have much if any backup power and a UPS of any kind is won't help if the nodes out.

All nodes have monitored battery backups.
If there is an extended power outage a generator is then brought out to supplement the batteries and keep the node online.

Luke_
Its all in your head
join:2015-08-27
Tempe, AZ

1 edit

Luke_ to DylanMitchel

Member

to DylanMitchel
What Fubar said, Plus

The length of time the plant stays powered depends on the current draw. Some power supplies only have 2.5 amps of draw and have lasted well beyond a day. Others are near the max of 22 amps and an hour is more what you would see. No matter what, every power supply has back up batteries, unless they were stolen, unit is malfunctioning, etc etc. As soon as the power supply looses commercial power, it sends an alarm to Cox's NOC and a tech may be ultimately dispatched if needed to investigate and get it running on their truck's generator or for longer instances, a portable generator.

Theres also some power supplies that have both battery and natural gas as a backup. The node does not go into telephone only or omit any services/frequencies. Its business as usual for it until the batteries drain.
Maltz
join:2011-01-08
Fayetteville, AR
Calix 844G
Netgate SG-2100
Ubiquiti U6-LR

Maltz

Member

If that's true... I've never seen internet last more than about 30 minutes into an outage, and 5-10 is more typical in the last couple I've seen. (They're fairly rare here, thankfully.) But doesn't the FCC require landline telephone to stay up for something like 8 hours or so into a power outage? If the node drops everything at the same time, it doesn't matter how long the eMTA battery lasts - that's nowhere near that requirement.

Luke_
Its all in your head
join:2015-08-27
Tempe, AZ

Luke_

Member

May have only one string of batteries (alot have two) along with being at a higher load. Or the batteries are going bad and need to be replaced. 5-10 mins is very quick too run out...Maybe the power outage affected the power supply area sooner than you and it was actually longer? Not sure, but doest seem very low
Maltz
join:2011-01-08
Fayetteville, AR
Calix 844G
Netgate SG-2100
Ubiquiti U6-LR

Maltz

Member

It wasn't a one-time event. The 5-10 minute failure has happened at least twice in the last couple of years, and at least the most recent time, it was an event at the substation, so about 2500 people (and our nodes) lost power simultaneously. (Pesky squirrels. lol) I've lived here 15ish years and never seen internet run for more than 30 minutes into an outage.

Still, I really can't refute what you're saying. I don't recall where I heard that the node goes into telephone-only mode, and whoever said that (or perhaps I myself) may have had it confused with the modems, which absolutely do that. I guess I'll just apply Occam's Razor and assume that Cox does a crap job of maintaining node batteries in my area.

If I still had Cox telephone and had paid for an eMTA battery, though, I'd be pretty upset when my promised 8+ hours of backup time was off by two orders of magnitude!