UPS Ideas ?

[BFL13]

This could be for an RV where there have been posts about TV receivers etc getting knocked out by slow switching 120v power inputs. In this case it is in the stick house. I have jury-rigged something using RV equipment, but looking for a better answer.

The internet to the house has two things that need plugging into 120v, so when we have a power outage we lose the internet. This can be bad for working at home situations, eg. The laptops, etc, have their own batteries of course.

I have rigged up a 27DC battery with a 300w MSW inverter, and plugged the two things into that. I have a spare deck mount converter on the battery and the converter is powered by stick house 120v. So that all works for being a UPS. However, the converter fan comes on every so often and is annoying. The inverter's fan is quiet so no problem there. It all gets as much air as possible.

So what do people do who know more about all this tech stuff? Thanks for any ideas.

I did run a kill-a-watt on it all to see what the power needs are. (all figures rounded off and averaged where they bounce around some)

1. Phone company equipment (two plug-ins) in stick house receptacles- total- 15w, 28VA, PF 0.55

2. In inverter receptacles- 14w, 31-40VA, PF 0.3- 0.46 jumping around.

3. All running off inverter and from the converter's 120v input-
45w, 58VA, PF 0.76

So drawing about double what it takes straight (58 vs 28 VA), but not worried about that increase in the hydro bill 🙂 . It is more about the converter's fan noise.

[opnspaces]

I would go with an off the shelf unit, but you're correct they don't keep a battery alive too long it there's much of a draw. I once tried to parallel a group 24 lead acid battery that I had in the garage, but the UPS just started to alarm as if it had a bad battery.

One thing to know about the consumer grade UPS's is that they are not true UPS's like what you have built, and that is why they can claim to have hot swappable batteries.

When the UPS is on 120v house current the power is just routed straight through the UPS and the battery is out of the picture. When the UPS detects a power drop it quickly (2 milliseconds) switches over to the battery. The idea is that the capacitors in the power supplies of whatever is plugged into the UPS will keep that piece of equipment alive for the 2ms required for the switch. So when running on the household AC you can unplug the battery to swap it out as it's not currently in use.

[theoldwizard1]

Gdetrailer wrote:

Also have a couple of Tripplite 1300VA units, 5 yr old and a 1 yr old) ...

FYI, according to their own specs, that unit will give less than 2 minutes of "ride through" when the output is above 650W.

[BFL13]

happy2rv wrote:
Do the two things that need to be powered really need 120V or are they using "wall warts" to provide DC from 120V? Most routers and modems use 5-12VDC. If that's the case, I would consider a "DC UPS" Something like this or this Much more efficient than converting 12V to 120V to convert it back down to 5 or 12V. There are lots of similar battery banks available, just make sure they can be used while they are charging as some of them are meant just to be used as a portable phone charger and not while they are being charged.

The fibre line comes from the street to a "feeder" on the house, which is connected to a "media panel" inside that needs 120v, then the modem is plugged into that plus it needs 120v too. One of them has a regular plug and the other has a wall wart.

The phone company also hands you two extension modems that you can use farther into your house from the main modem if you need that. Those things need 120v power too, but we don't need UPS for them

[time2roll]

At home? https://www.tesla.com/powerwall

Keep a lot more running than just internet and cable/satellite tv.

[happy2rv]

Do the two things that need to be powered really need 120V or are they using "wall warts" to provide DC from 120V? Most routers and modems use 5-12VDC. If that's the case, I would consider a "DC UPS" Something like this or this Much more efficient than converting 12V to 120V to convert it back down to 5 or 12V. There are lots of similar battery banks available, just make sure they can be used while they are charging as some of them are meant just to be used as a portable phone charger and not while they are being charged.

[BFL13]

Lots to think about from folks who have posted, thanks.

That last one has hot replacement batts too, but says this:

"Work though short blackouts & maintain a network connection / save files safely during longer blackouts: 1300va / 720w smart lcd battery backup uninterruptible power supply (ups) provides up to 64 minutes of runtime for an entry level pc system, and 10 min of half load runtime "

That is not very long! I like the idea of using an RV battery or two instead of what the unit comes with and get many hours. It is for when we lose power locally, but the phone company still keeps its going so there is internet to the house but no power.

If the outage is for longer, there is still the RV to use as a big UPS inverter/ battery bank and run extension cords to the house. But the first thing is not to lose the internet connection while in the middle of something important. Then rig up something longer term if required.

[Gdetrailer]

vermilye wrote:
If you expect to feed a separate UPS from your inverter when running without hookups, try it first. Many UPS will not switch back to a poor quality power source (such as a MSW inverter) or non inverter generator. I had one at home that refused to switch back to my 15,000 watt stand by generator. With the generator running, the UPS ran on its battery until it died.

SOME, not ALL UPS units are finicky about the incoming 120V.

UPS units must "time" and "synchronize" the waveform before cutting between battery backup and utility. Some but not all can be very sensitive to the 120V input frequency and waveform.

Tends to be OLDER UPS units which may have this issue, I have some 15 yr old APC units which sync fine with a generator, have one 8 yr old APC which does not. Also have a couple of Tripplite 1300VA units, 5 yr old and a 1 yr old) which do not mind being on a generator.

Ironically, the Triplites also have a frequency readout on the display and shows my utility frequency often varies from 59.6-60.2 hz..

To the OP, just buy a ready made UPS, much easier with less hassle than trying to reinvent the wheel..

Most of my UPS units tend to get about 5 yrs on a set of batteries and tend to be pretty reliable.

I would highly recommend Tripplite AVR series (YES, it IS MSW, but IT WILL work fine for computers and related computer equipment along with TV's Sat equipment and such). Tripplite does make PSW UPS units, they are considerably more expensive though

Like this..



$130 HERE

I would however recommend avoiding the Rack Mount version, seems that in the rackmount version they have a fan that runs 24/7/365 which tends to lead to a failure point of the UPS.. Seen a lot of complaints on that feature..

The tower version I have shown above does have a fan, but it ONLY runs when the UPS switches to battery (IE no utility) so the fan issue should not be a real problem down the road.

[vermilye]

If you expect to feed a separate UPS from your inverter when running without hookups, try it first. Many UPS will not switch back to a poor quality power source (such as a MSW inverter) or non inverter generator. I had one at home that refused to switch back to my 15,000 watt stand by generator. With the generator running, the UPS ran on its battery until it died.

[BFL13]

The inverter/charger is what my jury rig does now, but perhaps the EVO makes less noise.

I don't like the power box thing I linked above, since the recharger might not keep up with the draw, and also several poor reviews (although refuted somewhat wrt not maintaining the battery so it sulphated--not an issue for this application).

[theoldwizard1]

theoldwizard1 wrote:
If you don't mind the extra wiring (build a box to hide it), buy a pair of AGM golf cart batteries and a 500w-1000W PSW inverter. Buy a separate battery charger. You are in business and will have a very long "ride through" time.

Forget "extra" wiring ! The Samlex EVO-1212 has an "online" mode ! The only thing you need is batteries.

This option is also called “On-Line UPS Mode” (UPS stands for Un-interruptible Power Supply). In this mode, the Inverter Section of the EVO is the PRIMARY DC-AC source of power. The AC input source is the BACK-UP source of AC power. In this mode, even if qualified AC input is available (within the programmed voltage and frequency limits), the EVO will still operate in “Inverting Mode” and AC output will be provided by the Inverter Section as long as the batteries are in charged condition above the specified programmed value of low battery voltage

[BFL13]

So the APC UPS using the MH house battery bank does not need to be left plugged into a charger to keep it running when 120v is still on. It switches to inverter fast enough.

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EDIT--besides the modem for switching time, there is the gizmo the modem plugs into that converts from the fibre line to the house. Don't know about switching time for that. OK? That converter also is plugged into 120v, making the two things needing 120v.
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The OEM battery in the UPS recharges once the power comes back on? Or if you use a different battery, you recharge that with your converter or solar.

What did you have to do to connect the external battery to where the internal battery was?

[theoldwizard1]

A few years back, I did some research for a friend on residential/light commercial UPS for a friend. The bottom line is "you get what you pay for".

•Buy a Pure Sine Wave UPS. The cost difference between MSW and PSW should not be that much (10%-25%) with modern electronics ! Anuone charging more either is making big profits or is making a very old design. (10 years in electronics is "very old".)
• Replacement batteries are almost as much as a whole new UPS !!
• ALL UPS are designed to run for a LIMITED AMOUNT OF TIME, probably under 1 hour, but possibly as short as 15 minutes. Buyer beware. Read the specifications. (Short time mean smaller battery, lower cost, and less money invested in high heat protection.)
• "Switch over time" is an issue. The best commercial UPS are "online". That is, 100% of the time, the load is running off of the inverter. Battery charging is independent of the inverter. $$$ !!

If you don't mind the extra wiring (build a box to hide it), buy a pair of AGM golf cart batteries and a 500w-1000W PSW inverter. Buy a separate battery charger. You are in business and will have a very long "ride through" time.

[Dutch_12078]

BFL13 wrote:
That set-up using a different battery could work for me. I see this gizmo, but it is not clear if its recharger could keep up with the draw of the phone company's equipment via its inverter so I could just leave it plugged in same as my jury rig.

I don't know if the modem would get knocked out in "one cycle" or not. It takes a minute or two to get the internet back once it has power. Leaving it on the inverter all the time avoids that.

https://www.canadiantire.ca/en/pdp/motomaster-eliminator-powerbox-600-0112002p.html

No, a modem will not be knocked out on a less than one cycle switch. Very few electronics are. Some very expensive lab equipment can be sensitive to the near instantaneous switchover, but that's about it.

[rk911]

fj12ryder wrote:
Buy a commercially made UPS, no fan, no noise, no sweat.

+1

[STBRetired]

I have an APC UPS at the S&B to keep my internet connection alive. Was not all that expensive. I don't recall exactly what model it is as am not there at the moment. Will keep my connection up for about 18 hours with no power.

Hot swappable can be done either of two ways. The unit can have two batteries, where you can pull one out to replace with a fully charged one while it runs on the other, or it can have an internal LI battery that will keep the UPS running for about 30 seconds while you swap the main battery. In any case, you must have a fully charged battery to put in.

If I regularly experienced power outages of 12 hours or more, I would look into disconnecting the internal battery and using a group 27 AGM instead.