Click on on the coffee-maker, flick on the Air Conditioning, toast your bagel, flip on the computer, put on some tunes, heat that mug of water in the microwave for tea, and print some documents … Each of these uses point to different types of electrical quality problems that commonly occur with Mexican CFE electrical service, and the need to protect our treasured toys from common problems with electrical power.
Each of the above usages points to the need for different solutions for each kind of problem that comes up, daily, in our electrical/electronic lives. A quick review reveals a basic list of common CFE problems we hopefully choose to deal with … before they damage our toys:
- constant low voltage (dropping below 105 VAC)
- constant high household voltage (134 – 140 VAC)
- transient voltage spikes & voltage drops
- voltage surges
- rapid ON/OFF cycling
- lightning strikes
The wide variety of appliances, computers and electronics in our homes each~all have different electrical properties… each with its own particular Achilles’ Heel… each requiring different protection needs.
Where to start?
… at the beginning? …
That takes us outside to the meter, where the electricity comes into the house. We advocate using a good quality lightning arrester on each hot leg and the neutral wire coming into the house. In the USA, most power companies provide modest lightning protection, so this may not be a big an issue in Canada or the United States. (Note that even up North, you may have a backyard lightning collector system (often called your “sprinkler system”) with metal heads and metal/copper plumbing that gathers lightning and can pass it into your home. In that case, even lightning arresters, installed just after the meter, can’t stop lightning’s huge voltage and current surges. … Also note that lightnings powerful surges totally overwhelm UPS’s (Un-interruptible Power Supply … aka ‘No Breaks’ in Mexico), constant voltage transformers, voltage stabilizers, line conditioners and surge suppressors.
The next point to consider for power problems: Know that lightning arresters on your AC power lines do not stop lightning spikes coming in on phone lines or cable-computer internet lines or TV-cable lines. Lightning surges coming in through internet/TV cabling must be addressed right at the source ~ like at your primary modem/router ~ to make sure the board-melting surges don’t fry your cabled ROKUS, computers, etc. This means putting a serious surge supressor (NOT a cheap power strip) in the ethernet line(s) coming out of the router. …. Also note that some telephone and cable TV & internet providers reimburse their customers’ losses due to fused, fried, or melted electronics from lightning strikes. If this happens to you, inquire with your internet provider, as Cablemas has twice re-imbursed us for strikes that came in through their cables:
Protect your phone, internet, and TV with line-filters :
Note that good UPS’s and Line Conditioners/Power Conditioners can include sockets with line-filters to protect your phone/DSL/internet/cable TV lines. Also note that good UPS manufactures like APC or Tripp-Lite include replacement-cost protection for consumer electronics losses due to power or DSL/phone power problems, though these warranties often require that the UPS or Line Conditioner be purchased in the country where the damage occurs. .. See places like Office Depot or Tripp-Lite dealer for your current options. (punny?)
Next: Rank what’s important to you … and protect it .
If fotos, documents, and electronic records are important … then focus on your computer … and MAKE BACKUPS. …
What about the microwave oven or fridge with electronic controls, or printer, or high end stereo? … the television … or laptop computer? … Unlike most internet advice, modern electronics design says: The TV and Laptop computer are likely the most robust devices in your house, since modern TVs and laptop computers have “switching” power supplies that easily and automatically handle voltages that range from 100V – 240V – and they also generally have good surge suppression capabilities of 650 joules or more.
Power Outages – a very different issue from voltage spikes or surges:
A basic UPS offers good protection from power black-outs for our computers, disk drives, printers and all-in-one machines, BUT most UPSs only give back-up power protection …
Most UPS’s (‘No Breaks’) do NOT give adequate protection for typical power surges, power spikes, nor dirty power … Most UPS’s also do NOT generally protect us from consistently-high voltages that are so VERY common with CFE’s local transformer issues. The last 2 APC brand new UPSs we had gave NO adjustment/correction/protection from our block’s transformer tap set at 135V-140V.
Mexico is a “Type B” power provider, offering electricity at 127V +/- 10%.
This means that our Mexican household voltage can vary between 114V to 140V and still be “in spec” . …
Still, all UPS’s have batteries that give us some time to do controlled shut-downs of equipment during power outages. … BUT they do not generally protect your valuable equipment from voltage surges … nor from damaging constant high household voltage.
When we first moved to Mexico 10 years ago, we lost our workhorse old-school HP Laser-Jet to constant voltage at 137V , for which APC had to reimburse us $450 USD – because the “modern” APC UPS’s do NOT use the big old heavy constant-voltage transformers of old-school UPSs … which means ONLY 2006 and earlier UPSs often have large transformers that are set up as either voltage stabilizers that work on low (drooping) and HIGH voltages – and absorb voltage spikes. Newer UPSs (post 2006) have less & less surge suppression, and often NO protection from typical 135 – 140 V CFE power (especially true if your home is close to the block’s transformer).
Conclusion: Constant voltage transformers and ~ Line Conditioners ~ … and some Voltage Stabilizers with large transformers offer the best voltage control, but they use power all the time and can create a fair amount of heat, (which is good if you live in Minnesota, but not so good in the Yucatan). Voltage Stabilizers and Line Conditioners moderate both low and high AC line voltages back into reasonable ranges, providing stable clean power that is safe for computers and peripherals – but they are NOT cheap => $100 USD – $600 USD.
Less expensive UPS’s (less than $100) and some modern manufactured UPSs since 2006, rely on fast electrical switches to change to battery power when there are voltage drops on the line or when there is consistently low voltage. These new cheaper UPS’s do not protect from high household voltage or voltage surges. Even though these new UPS’s cost less, weigh less, protect from small/tiny momentary voltage spikes, and do not put out the heat of the older voltage-stabilizing models … they simply do not protect electronics from constantly high voltage or from larger or prolonged voltage surges.
If you want full protection, plan to spend $100 USD or more on a good UPS that includes voltage stabilization of low household voltage (90 VAC – 105 VAC) and high household voltage (134 VAC – 140 VAC), along with battery backup. … Or … buy the cheap UPS for its battery-backup feature (to give you time for controlled shut-downs during power outages) … and PAIR it with a good voltage stabilizer – each costing $50 or so, but the pair can give protection equal to a $300 all-in-one power conditioner.
UPS Selection Advice: Consider how many watts of power the UPS can provide (600VA, 1000VA, etc.) versus how big your loads are. Take into account how long you need your computers, routers et to run on UPS battery back-up. Multiply the total amps of your load(s) x 120V, and match it to the UPS capacity. A typical computer uses only 200W-400W (2A – 4A) – meaning a need of 400VA to give you 20 minutes or so to finish your work and shut down the computer.
If you want even better protection, consider buying a Line Conditioner in addition to the UPS’s battery back-up capability. Line conditioners clean up a wide variety of noise, dirty power, spikes, voltage variations, frequency problems, and surges, but they do not include battery back-up.
Appliance Protection: Microwave ovens are our household appliances most sensitive to power problems. As such, our microwave ovens are usually the next thing to consider protecting.
Newer high power 1600 Watt microwave ovens seem particularly sensitive to Mexico’s power problems. Their unusually higher power demands seem to push the limits of the modern oven’s electronics. Just like the modern UPS vs old-school UPS issues: even minor power problems can damage your shiny new modern micro-onda in ways that don’t affect older robust micro-wave ovens.
Since microwave ovens use much more power (1600 watts) than your computer (50 watts – 200 watts), the typical UPS that works for your computer simply does not protect a new microwave oven. Microwaves need a dedicated voltage stabilizer designed for electronics (read the box, some stabilizers are designed for “liñea blanca” fridges/dryers/washing machines – devices with motors – while microwave ovens et al need the “electronics” version of voltage stabilizers.
Modest quality entry-level high-capacity (1,600 W) voltage stabilizers cost $75 – $80 USD. Unlike UPSs, voltage stabilizers offer very good voltage control and modest voltage spike protection. Their voltage spike protection is typically good enough to protect microwave electronics controls circuits from common Mexican CFE issues. Their combination of high power output, voltage stabilization, excellent surge suppression, and some voltage spike protection make them a good option to protect your microwave oven or your refrigerator.
If your refrigerator (or washing machine or clothes dryer) are old-school and do not have electronic controls (no LED displays), then they probably DO NOT NEED protection. If instead, your appliances do have electronic controls or LED displays, then they could benefit from voltage spike and surge suppression protection, as provided by a good quality surge suppressor ($30 USD – $50 USD for a Tripp brand suppressor). Refrigerators and clothes dryers and washing machines run for years without experiencing power-related problems – unless your clothes dryer or fridge uses thermistors to measure temperatures
… Thermistor-based temperature sensors give false HIGH readings when CFE voltages fly up above 130V … meaning your dryer may shut off too soon (thinking it’s too hot) when set to “Auto-dry” settings if your CFE voltage runs high … same issue happens in reverse for some electronic-controlled fridges with thermistor sensors.
What about air conditioners? In general, air conditioners only need to be protected against direct lightning strikes and the lowest-tech problem … ants.
To protect against lightning striking a power line or transformer (the only way it would affect the air conditioner), you can turn off the breakers that lead to those appliances when a storm is imminent. Ant protection is a different matter … needing powdered insecticide … Ants and termites use our electrical conduits as super-highways once inside the walls – with off-ramps directly into our air-conditioner circuit boards.
Solution: Sprinkle ant powder or boric acid in the bottom tray of the air conditioner’s circuit board compartment – and possibly at the bottom of electrical outlets. Remove the covers – don’t touch the wires, contacts, or boards, and use a little rolled paper tube/funnel to sprinkle the powder across the inside of the bottom of the compartment or outlet, and replace the cover. This generally gives good protection for warm toasty circuit air conditioner circuit boards from becoming an ant nest – as has happened twice in our Merida home. …
Protecting Stereos, Satellite Receivers, Household Electronics etc:
All of these devices benefit from some protection, but they are nowhere near as sensitive to power problems as desk-top computers or microwave ovens. These things do not use much power (watts) which means a good but cheaper UPS + plus a modest (1000W) voltage stabilizer, or a good voltage suppressor ($30 – $50 USD) can do the job.
Since these devices are typically not sensitive to higher household voltage, the cheaper ($40 – $90) UPSs or cheaper lower power voltage stabilizers (1000 watt – $35) work fine – unless you have big voltage spikes from a big air-conditioner turning ON and OFF (yours or the neighbors?) ….
Note that laptop computers & TV’s typically tolerate between 100 – 240 VAC with no problems, but TV’s do NOT like being jolted “ON” and “OFF” rapidly. … The “ON” and “OFF” rapid cycling problem often occurs when CFE loses power at a transformer or switch and works on them … => HUGE issues. … We often have a brief blackout, but when CFE linemen ram the big gate switches back ON, they sometimes make 3 – 4 attempts to slam the switch (gate) shut. … The result? Power coming into your home bounces wildly ON and OFF multiple times.
Some better quality voltage stabilizers and UPSs have a short time delay built in before they send power to your TV, refrigerator, or microwave – a delay which may give protection from CFE’s ON-OF rapid cycling events. UPS’s rapidly switch to battery backup, so, they too may protect your devices from the jarring “ON” – “OFF” cycles that happen when the power company is having or fixing problems.
Power Strips as Surge Suppressors:
Why have power strips been left out of the discussion so far?
The actual surge suppression capabilities of most ($10 USD) power strips are nearly useless in the real world. e.g. How much protection do you get from an annual $50 auto insurance policy? The same applies for $10 power strips. Power strips are very useful for turning things completely “OFF”, to save both electricity and to protect devices from power problems while not in use. … Use a cheap power strip to rapidly & completely shut off microwave ovens, TV’s, receivers, etc at night or when you are out of the house, to save electricity and reduce pollution, but don’t trust them to protect appliances or electronics when they are switched on. There are more expensive power strips (like the Belkin Conserve Switch Surge Protector with Remote (F7C01008q) for $40 USD ) that offer 1000 joules of surge protection. For context: 650 joules of surge suppression is a minimum value to protect electronics etc.
Ground Problems: In many poorer countries, the neutral leg ( “ground” = “tierra“) of the public utility’s power lines is often NOT grounded, or it is only poorly grounded. This can cause some microwave oven transformers to explode (!!), and can damage some printers and other devices. Unfortunately, it can be wise to test whether the important key outlets in your house to see if they are actually grounded – (which requires finding a good earth ground).
Polarity & grounding issues should be corrected only by a qualified electrician (difficult to find in some poor countries).
Protecting Our Stuff: Even when we match the solution to the problem, the quality of the protective devices we buy makes all the difference. … Sola, Tripp, Fluke and APC have decades of reputations for making good quality components … and are available here in Yucatan. More cost-conscious homeowners can consider Mexican and Chinese manufacturers with an eye toward knowing that quality control from unit to unit can be spotty.
I’ve have tested six individual Koblenz brand voltage stabilizers ($75 USD each), and one of the 6 actually boosted 120V up to a circuit-damaging 145VAC, ruining a $300 Mosquito Magnet trap and damaging a clothes dryer. Four of the other five Koblenz brand voltage stabilizers worked fine for the last five years – while one went screwy in Year 3. ???
In any case, it is wise to use a good quality volt meter to measure voltages at key outlets in your home, and also to test the net resulting voltages coming out of your “protection” devices. Even some better quality manufacturers, like APC, sell cheaper devices that don’t work as advertised (causing us the loss of a $450 HP laser printer).
In 45 years of monitoring and massaging power quality, we’ve had zero problems with Tripp, Fluke or older Sola devices.
Disclaimer: All of the above information is for education and entertainment purposes only. Contact a qualified electrician to evaluate problems.
Why did I produce this article today?
A friend’s home has been having serious CFE problems for the last 6 months … with their battery backup units beeping infrequently … (but too often) …. flickering lights …. with the problems reaching a peak today when the power went out completely at 7:00 AM … their bi-directional meter stopped working … the CFE voltages on L1 & L2 were at 122V & 124V after I installed diablitos in place of the non-functioning meter. … but the L1 vs. L2 voltage was only at 204V (a phase issue) … and within ½ hour, the L1 – L2 voltage drooped to just 187V … not enough to run 220V air conditioners or 220V pumps … and then 10 minutes later… L2 fell to just 1.4 V … leaving CFE’s “220 V” service at … 122V … *sigh*
This meant re-wiring various breakers on their main panel – moving them from L1 … over to L2 … to make the water pump run … to power the battery backup UPSs … to power their internet router … and to open the heavy garage door. … CFE may come out today … (or not) …
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Feel free to copy while giving proper attribution: YucaLandia/Surviving Yucatan.
© Steven M. Fry
Read-on MacDuff . . .