German Clock in the USA 230V 50Hz to 120V 60Hz

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Palmbay

Palmbay

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German Clock in the USA 230V 50Hz to 120V 60Hz

I have been doing some research and it looks like the clock is going to run fast with the Higher AC frequency.

Question:

1. 230V to 120V from Germany to USA. Will this require a 120 to 230 transformer or will a USA 230V work? Rephrase, is Germany 230V to ground or is it 230V Phase to Phase?

2. Once the correct voltage is achieved, I am thinking a dimmer on one leg can compensate for the faster clock movement created by our AC frequency.

All your input is appreciated.
 
1. If you bring two wires to an appliance, and if there is 230 volts between the two wires, then the appliance is not going to know whether the two come from a phase-to-phase source or a phase-to-neutral/ground source.

2. A dimmer will alter the voltage, but not the frequency. I don?t think that will make the clock go slower.
 
The dimmer will only decrease the voltage, it will not compensate for frequency. A DC Motor will operate more slowly with decreased voltage, but not an AC motor. You will need a frequency converter to make this clock operate. It would probably be much easier and cheaper to just replace the motor with one designed for the correct frequency/voltage.
 
I am trying to get all of my options, so I might just sound like I am slightly informed.

It is an elderly man that made the clock years ago. It has lighting in it as well as an electrical AC motor.

The frequency was my main concern. I have read that it will affect the performance of the clock.

I have suggested replacement of the motor, but I am still left with the lighting.
 
Palmbay said:
German Clock in the USA 230V 50Hz to 120V 60Hz

I have been doing some research and it looks like the clock is going to run fast with the Higher AC frequency.

Question:

1. 230V to 120V from Germany to USA. Will this require a 120 to 230 transformer or will a USA 230V work? Rephrase, is Germany 230V to ground or is it 230V Phase to Phase?

2. Once the correct voltage is achieved, I am thinking a dimmer on one leg can compensate for the faster clock movement created by our AC frequency.

All your input is appreciated.
Click to expand...

German power is 230V to neutral, no such thing as two legs, either this option of 1 hot + 1 neutral or three phase like ours. but already answered; the clock won't know.

The clock is most likely using the frequency as a time base (especially an older clock) so it will run 17% fast no matter what you do. Check see if it has any fast/slow adjustment; If not you have a synchronous motor and can't do anything except build your own very accurate power supply.In England and I'm sure in Germany too if the frequency is under or over for a while it is corrected by the supply authority by doing the oppsite for a time; just to keep clocks accurate.

Hope this helps.
 
Palmbay said:
German Clock in the USA 230V 50Hz to 120V 60Hz

I have been doing some research and it looks like the clock is going to run fast with the Higher AC frequency.

Question:

1. 230V to 120V from Germany to USA. Will this require a 120 to 230 transformer or will a USA 230V work? Rephrase, is Germany 230V to ground or is it 230V Phase to Phase?

2. Once the correct voltage is achieved, I am thinking a dimmer on one leg can compensate for the faster clock movement created by our AC frequency.

All your input is appreciated.
Click to expand...

Tell the customer foreign appliances don't work in America, and vise-versa.
 
I recently wired a German made fountain pump in the lobby of a local business. The pump was for 50hz. Just installed a VFD next to the panel for the pump circuit. You could do the same thing for the clock. Just program the VFD for 50hz, with no ramp/soft-start. If you're puzzling on a German clock, I assume it's a high-dollar affair. If so, a couple hundred bucks for a little wee VFD probably won't be such a big deal.
 
The customer is about 75, and "made the clock when he was a young man". I don't think it is worth a whole lot, but it is priceless to this family.

Good idea on the VFD.
I did not know they made small ones. I have only limited experience with VFD's.

Who manufactures small ones?
What spec. did you use on the fountain? I can't imagine that was a very large pump.
 
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A clock is unlikely to get its timing from the power company's 50 or 60Hz because it's too sloppy. It likely has a crystal oscillator inside.

You'll have to dig into the specifications. Most switching supplies will handle incoming from 47-63Hz and 90-264VAC RMS. Failing that, many devices are rated to handle +/-10% on Voltage. Most transformers run better on 60Hz than 50Hz.

Get the manual or contact the manufacturer on the web for advice.

I don't think you'll find a single phase out VFD. They make single phase in, three-phase out, and 3 in 3 out, but I searched high and low for a 1-phase out for a 1-phase motor and came up empty.

Matt
 
There is no ratings or markings. It is a full custom clock. The old man is OLD. His memory is failing. His wife is the one I got the information I did out of. They can't even figure out what decade he made the clock in.

I am going to hook it up to 240V. If it does not keep time I may try the VFD.

Cost is no object to these people.

And all I want to do is do it right.
 
Palmbay said:
The old man is OLD. His memory is failing. .
Click to expand...

He may just may want to see it work again. If no damage will be done by the low hz, maybe he can take some pleasure in adjusting it daily.
 
megloff11x said:
I don't think you'll find a single phase out VFD. They make single phase in, three-phase out, and 3 in 3 out, but I searched high and low for a 1-phase out for a 1-phase motor and came up empty.
Click to expand...
Check out the TB Wood's drives. They're my preferred AC inverter drive and they make a fine DC drive also. Buy American! http://www.tbwoods.com/pdf/TBW-DrivesSelectionGuide207.pdf

For my fountain application, I used an X4 drive: http://www.tbwoods.com/pdf/X4B-4PG-Web.pdf These things are foolproof.
 
Palmbay said:
Good idea on the VFD.
I did not know they made small ones. I have only limited experience with VFD's.

Who manufactures small ones?
Click to expand...
Automation Direct, an internet based supplier of lots of things, has a very inexpensive line. go to www.automationdirect.com and select AC drives. The GS1-10P2, 0.25 HP AC DRIVE 120V 1 PH INPUT 230V 3 PH OUT is $99.00.

Another poster mentioned the frequency not being accurate enough for clocks ... that's how they worked until recent times. The utility power grid is complete across the US (and rest of North America, I think) and cumulative error is substantially zero. In 1973 when I had some involvement, if there are even instantaneous excursions beyond 59.98 to 60.02, causes were investigated FAST! If a clock tied to the power line was 2 seconds off WWV, I never heard of it. We displayed deviation in milliseconds, and it was typically, short term, within 200 ms.

The question is how close the 50 selected in the inverter will be ... to have to set the clock occasionally wouldn't surprise me.
 
megloff11x said:
A clock is unlikely to get its timing from the power company's 50 or 60Hz because it's too sloppy. It likely has a crystal oscillator inside.
Click to expand...

Not true for a clock that a 75 year old man made in his youth -- it was made in the era of vacuum tubes, not transistors. This will be a motor driven analog clock.

Also, the 60Hz from the utility grid is extremely accurate, and I suspect the 50Hz in Europe is also. Wikipedia says, "The frequency of large interconnected power distribution systems is tightly regulated so that, over the course of a day, the average frequency is maintained at the nominal value within a few hundred parts per million." That's plenty good for a residential clock.


Martin
 
Not Really:

Not Really:

mdshunk said:
I recently wired a German made fountain pump in the lobby of a local business. The pump was for 50hz. Just installed a VFD next to the panel for the pump circuit. You could do the same thing for the clock. Just program the VFD for 50hz, with no ramp/soft-start. If you're puzzling on a German clock, I assume it's a high-dollar affair. If so, a couple hundred bucks for a little wee VFD probably won't be such a big deal.
Click to expand...

Problem is that the 50hz from the VFD will not be accurate enough. The frquency from the Poco is carefully controlled to make the electric clocks run accurately.
 
LOL on the VFD idea! I seriously doubt it is a 3 phase clock motor! There are 1 or 2 single phase VFDs available for certain types of motors only, but they will likely cost $300+ and I'm not so sure they would be a good idea on any kind of 60(?) year old motor!

megloff11x,
Older motorized clocks usually use 1 phase synchronous motors, so they are definitely dependent upon frequency. You are probably thinking that a dimmer can sometimes be used to slow down a fan motor, so why won't it work for this? The reason ios, a dimmer doesn't really slow down a fan motor directly. It reduces the voltage, which reduces the torque. Less torque with the same load is the reason why the fan motor slows down, not a reduced speed reference. But the only kind of fan motors that can be controlled this way are what are called "Shaded Pole" motors. They are inherently current limiting, so reducing the voltage does not cause them to overload as it would with most other motors. They just run close to a stall condition almost continuously without damage. We perceive that to be a reduced speed, and in fact the difference is pointless to consider in that case.

You cannot do that with any other kind of AC motor however (Universal motors notwithstanding). Changing the clock motor is your only viable option. Synchron is a very common brand of synchronous clock motors, it's likely that they have a replacement available that will fit or can be adapted. Probably won't cost more than $50.

http://www.hansen-motor.com/synchindex.html
 
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I suspect that a conventional VSD would be a bad match for this clock. The clock has a tiny little motor; I would not want to trust it to the PWM output of even a .25 hp inverter.

I _might_ consider using the VSD with a transformer on the output, something to filter out the high frequency switching.

I would check to see if the clock has a standard movement which can be replaced. I doubt that this guy built the actual clock movement.

-Jon
 
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