Forums > General > Living, Working, Retiring

1 2 View All

whistler

Dec 20, 2006, 10:59 PM

Post #1 of 27 (5997 views)

Shortcut

What is the voltage in Morelia?

Can't Post | Private Reply

Many have posted in the forums that in their town the voltage is excessive and causes electronic items to fail prematurely.

Does anyone know what typical voltage levels are in Morelia and if a transformer is desirable to adjust it?

jennifer rose

Dec 21, 2006, 6:22 AM

Post #2 of 27 (5977 views)

Shortcut

Re: [whistler] What is the voltage in Morelia?

Can't Post |

The voltage in Morelia is the same as the rest of Mexico, which is the same as the U.S.

Karin

Dec 21, 2006, 7:14 AM

Post #3 of 27 (5969 views)

Shortcut

Re: [whistler] What is the voltage in Morelia?

Can't Post | Private Reply

I actually measured the voltage in my area. It is constantly between 135 V and 140 V. I am using voltage regulators for sensitive equipment.

Rolly

Dec 21, 2006, 7:29 AM

Post #4 of 27 (5962 views)

Shortcut

Re: [whistler] What is the voltage in Morelia?

Can't Post | Private Reply

The standard voltage in the USA 117V. In Mexico the 'standard' is 127V. In Mexico there is considerable variation in the voltage actually delivered to your home. It may be less than the 'standard' or quite a bit more. It also may vary by time of day or part of town.

All this boils down to: There is no reliable answer to your question.

Rolly Pirate

whistler

Dec 21, 2006, 9:06 AM

Post #5 of 27 (5947 views)

Shortcut

Re: [Karin] What is the voltage in Morelia?

Can't Post | Private Reply

That is way too high for audio gear and certain appliances. Are you using variacs (variable transformers) to drop it down, and if so, for what devices?

I am thinking the best thing for an area like Morelia is to have 2 or 3 10 amp variacs in the house for key equipment (for best performance and so life isnt shortened dramatically) and to use a simple line voltag monirt meter to keep an eye on it. I really enjoy my audio gear and dont want to have to replace it prematurely.

Could you confirm you are finding 135 to 140 volts in Morelia, and advise what exactly you are doing and for what type of device you are most concerned? Is it only for products you bring in form the USA that you are concerned?

Karin

Dec 21, 2006, 9:40 AM

Post #6 of 27 (5940 views)

Shortcut

Re: [whistler] What is the voltage in Morelia?

Can't Post | Private Reply

The voltage of 140 V which I am measuring here in Morelia is still within the allowed tolerance of 127V +/- 10%.
Under normal conditions this is OK also for products from the US. But when you get a power frequency overvoltage on top of it, products which are permanently on or on stand by mode may be endangered.

I recently lost equipment worth a couple of hundred dollars because of a 60 Hz overvoltage: several electronic tranformers of phones, electronic components of garage door opener and of audio components on stand by mode.

Small electronic voltage regulators with an output voltage of 110 V are available for 1000W. However I would like to have a regulator suitable for the whole house. So far I could not find a powerful regulator.

Besides by 60 Hz overvoltages electronic equipment can also be endangered by surges of lightnings. Surge arrestors are a good thing.

Rolly

Dec 21, 2006, 11:04 AM

Post #7 of 27 (5924 views)

Shortcut

Re: [Karin] What is the voltage in Morelia?

Can't Post | Private Reply

"power frequency overvoltage" and "60 Hz overvoltages"

Please explain what you mean by those terms. I'm a retired engineer (electronics), and I have never heard those.

Rolly Pirate

whistler

Dec 21, 2006, 1:46 PM

Post #8 of 27 (5909 views)

Shortcut

Line Voltage Regulation for Mexico

Can't Post | Private Reply

Although I might not be entirely correct as I am still studying this, this is what I think is the case –

US voltage level is 120 vac 60 hz +- 10% = 108vac – 132vac.
Mexico voltage is 127 vac 60 hz +-10% = 114.3 vac – 139.7 vac

So a Mexican electric company might generate power at 139.7 volts in Morelia, knowing that by the time the power reaches the distant suburbs it may have dropped to as low as 114.3 volts. They get away with deploying less equipment (to keep levels more consistent), yet still meet the regulatory requirements.

I would think most electrical devices sold in Mexico would be designed to work over the Mexico range, but suspect many US market items are not redesigned but still sold there.

So, US market stereo equipment, computer, or tv will look for 108 vac to 132 vac, but might see up to 139.7 vac. Result – possible, maybe likely premature failure.

http://sturgeon.apcc.com/techref.nsf/partnum/990-1286A/$FILE/990-1286A_EN_REV01.pdf

This is the pdf file of the APC Line-R LE1200 automatic voltage regulator – I would be comfortable with three of these – one for the tv, one for stereo equipment, and one for the computer.

Not for blenders, airconditioners, power tools, refrigerators. Maybe a variac / variable transformer would be better for these.

Karin

Dec 21, 2006, 2:20 PM

Post #9 of 27 (5897 views)

Shortcut

Re: [Rolly] What is the voltage in Morelia?

Can't Post | Private Reply

How would you call a 60 Hz voltage which is higher than U + 10 % ?

Karin

Dec 21, 2006, 2:24 PM

Post #10 of 27 (5894 views)

Shortcut

Re: [whistler] Line Voltage Regulation for Mexico

Can't Post | Private Reply

Maybe I am wrong, but I think the acceptable tolerance in the USA is only +/- 5 %.

Rolly

Dec 21, 2006, 2:30 PM

Post #11 of 27 (5892 views)

Shortcut

Re: [whistler] Line Voltage Regulation for Mexico

Can't Post | Private Reply

Don't put too much faith in that 127V ±10% standard. While it is not common to exceed 140V, under voltage and brownouts are quite common; and they, too, can be destructive.

Where I live, I am blessed with pretty steady 120V at my house. However, I have lost a motherboard, a printer and a DVD player to spikes caused by arching on the line. The power is not always as clean as it needs to be. I would like to have a UPS for my AV system and my computer desk, so I could be complete isolated from the garbage that CFE sells at such a high price.

There is no grid in Mexico, so each power plant is a stand alone. Thus there is no need to maintain exact frequency control, so the line frequency is usually about 60Hz. In my area it consistently runs a but over 60, so clocks that count the line frequency run fast. That is more of a nuisance than a problem.

Rolly Pirate

Karin

Dec 21, 2006, 2:33 PM

Post #12 of 27 (5891 views)

Shortcut

Re: [whistler] Line Voltage Regulation for Mexico

Can't Post | Private Reply

Maybe you do not need a sepate voltage regulator for your TV. Modern sets have a regulator already built-in.
Example: The power requirement for my Sony TV is 120 V - 240 V AC, 50/60 Hz.

Rolly

Dec 21, 2006, 2:36 PM

Post #13 of 27 (5888 views)

Shortcut

Re: [Karin] What is the voltage in Morelia?

Can't Post | Private Reply

"How would you call a 60 Hz voltage which is higher than U + 10 %"

I'm sorry, I don't know what you mean by U+10%.

The line frequency (60Hz) and the line voltage are separate issues and are, generally, unrelated.

Rolly Pirate

Rolly

Dec 21, 2006, 2:39 PM

Post #14 of 27 (5885 views)

Shortcut

Re: [Karin] Line Voltage Regulation for Mexico

Can't Post | Private Reply

Are sure that there is not a switch that allows you to select which voltage (120 or 240) you will be feeding to the set? If it does truely have a sensor that automatically adjusts for the voltage, that's news to me.

Rolly Pirate

Karin

Dec 21, 2006, 2:52 PM

Post #15 of 27 (5878 views)

Shortcut

Re: [Rolly] Line Voltage Regulation for Mexico

Can't Post | Private Reply

Yes, definitively there is no selector switch on both of my sets.

U + 10 % = 110 % of rated voltage = 1.1 x 127 V = 139.7 V

A voltage higher than 139,7 V in a 127 V system (outside the accepted tolerance) is a power frequency overvoltage.

Kimpatsu Hekigan

Dec 21, 2006, 4:01 PM

Post #16 of 27 (5869 views)

Shortcut

Re: [Karin] Line Voltage Regulation for Mexico

Can't Post | Private Reply

I believe the terms of art for utility line frequency are overshoot and undershoot.

Other terms include voltage surge (a transient increase in voltage or current with a duration of a few microseconds); and voltage sag (reduction in the AC voltage, at the power frequency, for durations from 1/2 cycle to a few seconds).

And overvoltage and undervoltage refer to a voltage with a value at least 10% above or below, respectively, the nominal voltage for a period of time greater than 1 minute.

FWIW,

-- K.H.

Before enlightenment: Chop wood, haul water.
After enlightenment: Chop wood, haul water.

jerezano

Dec 21, 2006, 5:52 PM

Post #17 of 27 (5855 views)

Shortcut

Re: [kimpatsu_hekigan] Line Voltage Regulation for Mexico

Can't Post | Private Reply

Hello,

This is a real interesting thread.

Here in Jerez, Zacatecas the line voltage at my house is almost consistently 140v ac. The frequency is usually 59.6 hz.

I have for my computer a voltage regulator. I also have an Uninterrupted Power Supply which was manufactured in the USA and set to USA standards. First of all, you cannot and must not use the two in train.

However there are usually two times daily when I cannot use my UPS because it will go into automatic shut down mode. Those times are about 8:00 AM when the breakfast cooking load and the hot water load begins peaking. The other time is about 5:30 to 6:00 PM. I have no idea what is causing the problem at that time.

When I want to use my computer during those times I simply unplug my computer from the UPS and plug it into the voltage regulator. System works fine.

So why do I use the UPS at all? Because if I am using the voltage regulator and there is an instantaneous power outage (and we have many of those) my computer shuts down improperly. And I have had to reformat disks twice because of that type of shutdown. With the UPS, I get warning and a 10 minute controlled shutdown.

Since I can't do anything about the two daily periods with problems, I try to work outside of them and I use my UPS at all other times to prevent any future necessity of reformatting disks and reinstalling all my programs.

Somebody mentioned voltage switches on the back of TV's and other equipment. Those switches are to select either the 117 volt USA standard or the 240 v European standard. The Mexican supply of 140 volt will usually work well with the 117 volt USA standard but light bulbs, and many other items burn out more quickly.

Adiós. jerezano.

whistler

Dec 21, 2006, 10:56 PM

Post #18 of 27 (5828 views)

Shortcut

What voltage are Mexican products made for?

Can't Post | Private Reply

When you buy electronic items in Mexico, are they made for and labelled for the mexico 127 volt ac standard? (I think the acceptable range for utilities to provide in Mexico is something like 114.3 volts to 139.7 volts).

whistler

Dec 21, 2006, 10:57 PM

Post #19 of 27 (5828 views)

Shortcut

Re: [jerezano] Line Voltage Regulation for Mexico

Can't Post | Private Reply

What brand and model of regulator are you using? Does it work well?

whistler

Dec 21, 2006, 10:58 PM

Post #20 of 27 (5828 views)

Shortcut

Re: [jerezano] Line Voltage Regulation for Mexico

Can't Post | Private Reply

Then when you are using your UPS instead of the regulator, your equipment sees 140 vac. Dont you feel you are shortening the life of the equipment?

Ron Pickering W3FJW

Dec 21, 2006, 11:21 PM

Post #21 of 27 (5826 views)

Shortcut

Re: [whistler] Line Voltage Regulation for Mexico

Can't Post | Private Reply

If one wanted to go to the trouble, one could set up a 12 V battery with a mexican battery charger that should handle the Mexican voltage and use a 12V inverter for ones computer or sound system. That would alleviate all voltage problems as far as either are concerned. I use modified square wave units but pure sine wave units are available at a higher cost.
I use them in my RV for all my computer & electronic stuff and I'm sure Jonna does also.

http://www.xantrex.com/.../1/pt/29/product.asp
Getting older and still not down here.

Georgia

Dec 22, 2006, 7:36 AM

Post #22 of 27 (5792 views)

Shortcut

Re: [whistler] Line Voltage Regulation for Mexico

Can't Post | Private Reply

We've had problems here in our village with surges and brownouts. Our solution was to put a whole house voltage correcter on each of our two meters. Expensive, but effective.

hassmarciaj

Dec 25, 2006, 3:38 PM

Post #23 of 27 (5714 views)

Shortcut

Re: [Georgia] Line Voltage Regulation for Mexico

Can't Post | Private Reply

A voltage corrector for the whole house is what I plan to buy, as well. Just found out about the from a good electrician. 4000 -volt one costs around 2500 pesos, I believe. Woule like to hear what price Georgia paid in order to compare to the Cuernavaca outfit that sells them.
Sincerely, Marcia Hass

Georgia

Dec 25, 2006, 4:51 PM

Post #24 of 27 (5704 views)

Shortcut

Re: [hassmarciaj] Line Voltage Regulation for Mexico

Can't Post | Private Reply

We paid around $400 for each of the two we had. They handle 110 and 220 with a good range of voltage: 85 to 150. The 4000 number doesn't sound right. Do you mean watts?

johanson

Dec 25, 2006, 5:35 PM

Post #25 of 27 (5696 views)

Shortcut

Re: [Georgia] Line Voltage Regulation for Mexico

Can't Post | Private Reply

4000 volts? You have got to be kidding. Standard voltage in Mexico is 127 +/- 10 %. The best you might get would be 2 times that if there is a 180 degree phase shift or where I live (Ajijic) because our neighborhood has 3 phase and each phase is 120 degrees out of phase of the other, the highest voltage I could get would be 2 X 127 X 87% +/- 10% or 221+/- 10%

What I believe you meant to say was a whole house voltage regulator rated at 4000 watts. That seems a little low. I have a diesel backup generator rated at only 4000 watts and I am only able to put some of the circuits on line at any one time, when using it as a power source. Some of the high power usage items I have are things like a water pump for a second aljiba, a water pump for water pressure, a water pump for irrigation system, refer, TVs, Micro, etc, etc, It doesn't take much to use up those 4000 watts. Heck on electric heater, something I am too cheap to use, consumes 1500 watts

Also when you buy a new voltage regulator of the type offered at computer stores etc, look at the specifications, typically they will either raze or lower the voltage by a set 10%. Think about that. If your line voltage is 145 volts, something quite frequent in some neighborhoods, your line voltage will only drop down to 131 which is still too high or not good for (life shortening) for many items built to US specifications.

Remember things are often very different here, unlike the US, for example where one has single phase electricity in their homes with say 120 and 240 volts available, in my Ajijic neighborhood 3 phase electricity is all that is offered, each phase being 127 Volts +/- 10% and any two phases being 221 volts +/-10%.

(This post was edited by johanson on Dec 25, 2006, 6:20 PM)

1 2 View All