# 50Hz or 60Hz... what's the deal?



## TSOJOURNER (Dec 16, 1999)

I searched the threads here, but I still can't find the answer. I am not an electrical genius, so I am wondering what is the difference between a 50 or 60 Hz generator (other than the 10 Hz, or the fact that Europe is on 50 Hz)

Thanks.


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## bossk (May 8, 2008)

This may shed a little light on your question!

Utility frequency - Wikipedia, the free encyclopedia


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## newpbs (Apr 21, 2008)

I'll share what I know and ask more questions so that others that Know more than myself can answer. 

In the U.S. we have 60 Hz which means that the alternating current reverses 60 times every second. This frequency is very constant and some equipment relies heavily on this constant frequency. Other places, Europe and I believe Canada, has the current reverse at 50 times each second. Some things will operate fine on either current. If the equipment is designed to run on 50 or 60 Hz there is no problem.

Here is the question that I have for you. What specific concerns do you have? Is there something that you are concerned about operating either here or elsewhere?

I'm sure there are folks here with more information on the subject. If you can provide more information, you will get a better result.

Good luck, Paul


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## bossk (May 8, 2008)

I'm pretty sure we're 60hz up here in the North


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## brak (Jan 5, 2007)

considering that real frequency varies quite a bit (it is not unusual to have variation of 10-15% even in US) i think the number is more of a guideline.


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## TSOJOURNER (Dec 16, 1999)

brak said:


> considering that real frequency varies quite a bit (it is not unusual to have variation of 10-15% even in US) i think the number is more of a guideline.


No.. actually it is pretty much 60.. all the time. Not really relevant to the discussion but some clocks are even timed solely by line frequency. It really is that stable. 
Frequency isn't important to most AC devices you might find on a boat. Voltage is, however, and if you go somewhere that has 50 Hz use that as a clue to get the appropriate transformers to step down the voltage.


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## SEMIJim (Jun 9, 2007)

sailboy21 said:


> No.. actually it is pretty much 60.. all the time. Not really relevant to the discussion but some clocks are even timed solely by line frequency. It really is that stable.


Correct. Here's the last five days of data from my UPS at home, for example:

freq: hi: 60.2 @ 22:04:36, low: 60.0 @ 00:00:03, avg: 60.0 (+/- 0.0)
freq: hi: 60.2 @ 01:34:35, low: 60.0 @ 00:04:35, avg: 60.0 (+/- 0.0)
freq: hi: 60.0 @ 00:07:49, low: 60.0 @ 00:07:49, avg: 60.0 (+/- 0.0)
freq: hi: 60.2 @ 23:09:10, low: 60.0 @ 00:08:47, avg: 60.0 (+/- 0.0)
freq: hi: 60.2 @ 01:29:12, low: 60.0 @ 00:09:10, avg: 60.0 (+/- 0.0)

Those highs of 60.2Hz might've been just one sample out of the entire 24-hour period, and it's still only a 0.3% change.



sailboy21 said:


> Frequency isn't important to most AC devices you might find on a boat.


Well... That's not necessarily true. All kinds of things, such as motors (as in compressors) to anything with a transformer might "care." Your smart charger might care.

newpbs, I'm fairly confident Canada is on 60Hz. Don't know about Mexico. Much of Europe is on 50Hz (and 220V).

To the OP: If you're a N. American on a N. American boat: You want a 60Hz generator. However, unlike the power utilities, I can guarantee you 60Hz is only the "wishful thinking" rating. In reality its output frequency will wander all over creation.

Here's some frequency data from when we've been running on generator, during Yet Another DTE Failure:

freq: hi: 60.0 @ 12:05:38, low: 53.8 @ 06:25:38, avg: 58.2 (+/- 1.4)
freq: hi: 60.2 @ 21:06:17, low: 52.8 @ 08:46:17, avg: 59.5 (+/- 1.1)
freq: hi: 60.0 @ 00:09:30, low: 55.5 @ 18:09:33, avg: 59.1 (+/- 1.1)

Those are some pretty serious excursions. The various AC-powered clocks in the house are utterly worthless when this happens.

Jim


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## TSOJOURNER (Dec 16, 1999)

SEMIJim said:


> Well... That's not necessarily true. All kinds of things, such as motors (as in compressors) to anything with a transformer might "care." Your smart charger might care.


Yeah.. I was probably a little off on that statement. I like how Wikipedia puts it:

"Unless specified by the manufacturer to operate on both 50 and 60 Hz, appliances may not operate efficiently or even safely if used on anything other than the intended frequency."

That said, any charger I have looked at recently has the 50/60Hz rating. If it claims to be "smart" and "marine" it had better work if I sail across the sea! Also common laptop and desktop computers can run on either. The label plate should say what power the device can run from i.e. 120/240 VAC 50/60Hz. You can change voltage but you can't change frequency so make sure what ever you plug in isn't going to blow up! If you have ever been in an environment where the line frequency drops (like an older heavily loaded genset on a ship) you would be familiar with the moan of induction motors running slower, lights flickering at a different rate, and the EO spewing cuss words... Never mind, pesky flashbacks


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## Sapperwhite (Oct 21, 2006)

Bossks wikipedia link is a good one, take a look at the map at the link and you'll get an idea of when different freq systems are used. Basically, if you live in north america, and everything (electric powered) you own and buy is for north american markets, then get a 60Hz gen set.

You won't see a variation of 10% in frequency in a modern system. Frequency is strictly controlled, and frequency relay schemes will function to control frequency way before the sytem gets close to a 6Hz varition. 
In the east, we control time error (frequency variation) at 2 seconds. That means we correct system frequency when it drops from 60.00Hz to 59.98 (or from 60.02 in high frequency conditions).

Under frequency relays are set differently, but generally around 59.3, 58.5, and 57.9Hz for three levels of load shedding. Those values aren't golden, just guidlines. Some areas have five levels of under freq relays, and some areas have them set at different levels. These relays will essentially blackout designated amounts of load to regain system frequency to prevent cascading whole system loss (whole system blackout). Generation trips at 57.5Hz (also not golden. Different units are set differently, but in that proximity.) 

Its a long boring story, but i can direct anyone interested to a ton of information that is publicly available if you are really interested in generation and transmission systems, relays, controls, regulations, economics, markets, blah blah blah


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## Sapperwhite (Oct 21, 2006)

SEMIJim said:


> To the OP: If you're a N. American on a N. American boat: You want a 60Hz generator. However, unlike the power utilities, I can guarantee you 60Hz is only the "wishful thinking" rating. In reality its output frequency will wander all over creation.
> 
> Here's some frequency data from when we've been running on generator, during Yet Another DTE Failure:
> 
> ...


Yes, a single generator doesn't have the system stability or control schemes that an entire transmission RTO has. All my prev post was in regards to transmission and distribution systems, not a single generator.

You probably will see a big frequency drop on your single gen when big load like an AC unit or refrigerator comes on.


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## sailingdog (Mar 19, 2006)

North America is basically 60 Hz... Europe is basically 50 Hz, the rest of the world is a mixed bag, depending on whether the US or Europe helped build their infrastructure.


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## camaraderie (May 22, 2002)

Down Island a lot of islands are on 220V/50Hz power grids. When you plug into a marina, they give american boats a transformer that changes the voltage to 110V/50 Hz...good enough to run most American electronics but it can cause havoc with stuff that draws big current that is not rated for 50/60Hz operation and shorten the life of things like Air conditioners, motors, microwaves etc. ...It will also eat up your power cords and sockets if you have high loads from non-50hz stuff.


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## xtatico1404 (Jan 20, 2008)

The reason why frequency is so closely controlled at the utility level is that the useful life of a generator (utility sized generators are in the millions of dollars dependeing on the MW output) is heavily affected by frequencies other than those for which they were designed. Part of the protection system of powerplants have under-over frequency relays and once the frequency goes outside the set parameters, the generator will be taken off line. Good frequency regulation for 60 HZ is about +/-0.02Hz at maximum, so there are NO 10-15% frequency variations at utility level. The system can go below or higher than that, but the life expectancy of millions of dollars is heavily impacted and for economical reasons the utility will not allow it.

The key....if it says 50/60Hz, it will work. If it says just 60Hz, just don't use it at 50Hz. It will probaly work, but internally the unit will suffer and die prematurely. 

Cam is spot on regarding the transformers. Those things are super cheap and not very reliable.


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## tomaz_423 (Feb 5, 2006)

A practical experience: My old electric razor was rated 50/60 Hz with a switch to choose between 110-120 voltage or /220-240V.
We have 220V 50 Hz in Slovenia.
When I traveled to the states the razor worked noticeably better - I could not believe the difference at first, but I was shaving faster. Really.
The new one runs on battery, so there is no difference.
As a general rule:
Most small power transformers (laptop, phone or ipod or camera chargers) works quite well on both frequencies and all voltages. It transforms to lower voltage, that transforms into DC (capacitors must be a tad bigger to handle 50 Hz). They are sized to operate in worst case combination. If they get more V, the excess voltage is sometimes thrown away (sometimes as heat), some better devices uses voltage sensing at input, but not the cheap ones.
The very low power consumption (for household usage) of that chargers easy justify they just throw away the extra Volts and Amperes and the actual device (laptop or camera) can have advance power management system to compensate for low quality of delivered power.
When the loads go higher (microwave, power tools, TV, larger motors...) it makes sense to use energy more economically (mainly to prevent overheating or other damage), so we would see less dual power/dual frequency devices.


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## capecapt (Sep 1, 2008)

*50/60 isolators*

You can purchase units from companies such as Charles or Mastervolt that will take either 50 or 60 hz in and put out a clean 60 for your equipment, if that is what you need. If you plan international sailing, it is the thing to do. The expanse now will save a lot of greif later. Good luck


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## denverd0n (Jun 20, 2008)

As far as traveling internationally, the thing to do is take a look at each thing you intend to plug in. I recently spent a week in Paris. I took my laptop computer, an electric razor, my cell phone, and a battery charger (for the rechargeable batteries for my camera). Every single one of these devices was rated for 110-240 volts and 50-60 hz, so I did not need any kind of electrical transformer or converter. All I needed was an adapter to convert the American style plug to fit into a European style socket.


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