looking for protection against power outages

[KEIN NEIN]

Hello, greetings from Mexico

So, power outages are becomming very common in my region, especially in spring/summer.

We want to protect the home appliances & electronics (2 refrigerators, 1 freezer and 1 computer to be precise) but don't know what is best.

The problem is that most of our house isn't grounded. I have read that earth ground is essential for the proper operation of any of these devices. Is this true?

If not, my second question would be: for this scenario, which is better, or should I buy both? Maybe there's an electrical/energy engineer from Mexico who can help me out with this.

I found this AVR that is rated 2000W, note that I couldn't find the wattage numbers for the fridges (but I see they are 14 cubic feet each at most) and the freezer is 70W:

https://www.cyberpuerta.mx/Energia/Proteccion-Contra-Descargas/Reguladores-de-Voltaje/Regulador-Koblenz-ER-2550-134J-2000W-Entrada-90-145V-Salida-120V-6-Contactos.html

This is 950 MXN (mexican pesos) with shipping, I liked it because it offers a 7 yr warranty with a 25,000 policy for any connected equipment to it, plus Koblenz is a brand I recognize. So, third and last question: Do you have any other suggestions?I'd like it to keep it under 1000 MXN

amazon.com.mx         walmart.com.mx          cyberpuerta.mx           are some sites I buy from if you want a place to start

thanks a lot.

[Benta]

That thing won't help one single bit.
It's a voltage stabilizer, nothing else. It removes noise from the mains.

You need a UPS (uninterruptable power supply) with batteries (lots of them). APC is a good brand.
This will keep your supply running for 10...20 min.
If your outages are longer, you'll need to combine the UPS with a gas-driven generator. This will run for as long as you keep the gas tank topped up.

[m k]

Old style start battery may be 100Ah.
It's also 12V, so 1200Wh ideal.

There is also a thing called deep cycle.
Generally batteries don't like it.

Lead-acid battery is specially against a deep cycle, it likes to be fully loaded.
Maybe half of that ideal max is what can be used, so 0.6kWh of energy.

Then just multiply needed energy, missing grid time and efficiency.
And you have a ball park of needed batteries.

[Kim Christensen]

Get a backup diesel or gas generator with auto switchover. Doesn't matter if the fridges are without power for the short time it takes for the generator to come online.
You just need a UPS for the computers that'll power them until the generator kicks in.

[Benta]

Well, seeing that 1 MXN is around 6 US cents, I don't see any realistic chance within a budget of 950 MXN.

[KEIN NEIN]

So these fridges and freezers need a completely different solution, I see, thanks.

But I still wonder if I stretch my budget and buy an UPS, is grounding important?

[Benta]

No. And the right term here is "earthing".
"Grounding" is ambiguous.

[KEIN NEIN]

I didn’t know it, thanks

[Rick Law]

...
There is also a thing called deep cycle.
Generally batteries don't like it.

Lead-acid battery is specially against a deep cycle, it likes to be fully loaded.
Maybe half of that ideal max is what can be used, so 0.6kWh of energy.
...

Sealed Lead Acid (SLA) for autos/cars/trucks particularly dislike deep discharge.  Marine SLA batteries are deep discharge batteries as with some RV batteries.  Marine batteries are designed for boats/yachts and have been in use for ages.  So, marine batteries are (should be) well adapted to deep discharge.  Looking for Marine battery is more straight forward since boats are boats and there is hardly any confusion.  RV here refers to those mobile trailers like some Winnebago RV's -- the living space on wheels type of RV but NOT the off-road 4 wheel motorcycle type of off-road RVs.  From my shopping experience, "Marine battery" is a commonly use term to refer to deep discharge battery.

I was told that Gel can handle deep discharge as well as Marine batteries.  But that was words of month that I had not look into if true or not.

If you want Lead Acid, make sure it is the deep-discharge kind.

[BillyO]

1000 MXN is about$56 USD.

I cannot think of a reasonable solution to your problem for under 15,000 MXN.

[Andy Chee]

We want to protect the home appliances & electronics (2 refrigerators, 1 freezer and 1 computer to be precise) but don't know what is best.

I'd like it to keep it under 1000 MXN

The best protection is a generator automatic change over switch with battery standby (UPS). 

For 1000MXN, you might be able to purchase a small second-hand generator and a manual change over switch.  If you can get a diesel generator, you may be able to get free fuel by using waste vegetable cooking oil.

How long are your power outages?  If the outage is only for a few hours, you don't really need power for the fridge & freezer.

[golden_labels]

Use portable freezer packs. Keep them frozen, move some to the critical areas of the fridge during power outage. You can probably get them at $1 per unit. Prefer solid ones, as you’re going to use them with food. One doesn’t know, what they put inside. And uou don’t want your food to be soaked with car antifreeze, if some thin bag breaks.

If that isn’t an option, you may go for permanently storing big bottles with water on fridge’s door (not freezer!). This is normally not offering much and takes up space, but may be enough to buy you a few hours during a power outage. Don’t store them on shelves (will worsen cooling), don’t just use your daily drinks (will just waste energy).

[tggzzz]

Use portable freezer packs. Keep them frozen, move some to the critical areas of the fridge during power outage. You can probably get them at $1 per unit. Prefer solid ones, as you’re going to use them with food. One doesn’t know, what they put inside. And uou don’t want your food to be soaked with car antifreeze, if some thin bag breaks.

Make them yourself, with 120g of salt in 1 litre of water.  Use a plastic bottle, not glass, and only fill 90% with the brine.

The more surface area, the better.

[MrAl]

Hello, greetings from Mexico

So, power outages are becomming very common in my region, especially in spring/summer.

We want to protect the home appliances & electronics (2 refrigerators, 1 freezer and 1 computer to be precise) but don't know what is best.

The problem is that most of our house isn't grounded. I have read that earth ground is essential for the proper operation of any of these devices. Is this true?

If not, my second question would be: for this scenario, which is better, or should I buy both? Maybe there's an electrical/energy engineer from Mexico who can help me out with this.

I found this AVR that is rated 2000W, note that I couldn't find the wattage numbers for the fridges (but I see they are 14 cubic feet each at most) and the freezer is 70W:

https://www.cyberpuerta.mx/Energia/Proteccion-Contra-Descargas/Reguladores-de-Voltaje/Regulador-Koblenz-ER-2550-134J-2000W-Entrada-90-145V-Salida-120V-6-Contactos.html

This is 950 MXN (mexican pesos) with shipping, I liked it because it offers a 7 yr warranty with a 25,000 policy for any connected equipment to it, plus Koblenz is a brand I recognize. So, third and last question: Do you have any other suggestions?I'd like it to keep it under 1000 MXN

amazon.com.mx         walmart.com.mx          cyberpuerta.mx           are some sites I buy from if you want a place to start

thanks a lot.

Hi,

What part of Mexico are you located in?
Even more important, how long do your power outages last, and with what frequency.  In other words, does the power stay off for 10 minutes, 1 hours, 10 hours, and then come back on for a whole day or two or go off again the next day.  This is important to know because you have to know how long you have to recharge the batteries also.

The LiFePO4 batteries are amazing for these purposes but not sure if anyone makes a UPS that uses those yet.  Most of them use Lead Acid.

The cheapest I know of that will do 1000 watts or so is about 2000 to 3000 in your stated currency, and that may not be enough for refrigerators and other stuff with motors.

It would be interesting to know what area you are in Mexico because I know parts of California are having this same problem now too, with rolling blackouts.

[calzap]

Try to remedy the “grounding” problem of your house to the maximum extent possible.  You can probably do a lot without a total rewire.  A ground rod properly connected to your service entrance panel is a start.  Then the ease of running ground wires to lights, appliances, etc. depends very much on the structure of your house.  If it has an attic or crawl space, you can do a lot.  If it’s on a slab with a flat roof, it’s harder.  In any case, you can install GFCI (aka RCD) outlets, which will improve safety even without ground wires.

How bad will it be if your computer, suddenly stops due to power outage?  Is it running critical equipment or doing something medical where a sudden shutdown is a problem?  If not and you have a generator, no big deal.  Just restart your computer when it gets power from the generator.  For running major appliances, especially for hours or days from a UPS, you’ll need one with very big, very expensive batteries.  I recommend a small propane-powered generator for the loads you mentioned.  With propane, you never have to worry about stale fuel issues, which you do have to consider with gasoline or diesel.  Be sure to have a spare propane tank.

The generator should be completely outside the house (not in garage, basement, etc.) to avoid CO poisoning.  If your outages are occasional and you have a small number of items to power, just buy some extension cords.  “Hard wiring” a generator to a house is a complex issue.  There are many ways to do it wrong, some of which are exceedingly dangerous.

Mike