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Old 01-04-2015, 01:58 PM   #1
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From 50Hz to 60Hz

What would be involved with converting a generator from 50Hz to 60Hz?
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Old 01-04-2015, 02:02 PM   #2
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Most generators can be run at either frequency, and can be wired for 220v/50, 120v/60 or 120/240/60. It depends on the model, the type of voltage regulation, etc. The manual will cover this, well some do.
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Old 01-04-2015, 02:06 PM   #3
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What would be involved with converting a generator from 50Hz to 60Hz?
1800 vs 1500 RPM. In some cases an electronic circuit board may need to be replaced. Armed with SN the specific mfr can give more details.
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Old 01-04-2015, 02:44 PM   #4
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What would be involved with converting a generator from 50Hz to 60Hz?
Most electrical stuff doesn't mind whether it's 50hz or 60hz.

Here in Europe all outside work must run on 110 volts by law, so contractors use step down transformers to reduce the voltage from 220/240. Everyone uses standard 60hz equipment on the local 50hz supply, no problems.

No too sure how an 60hz inverter would like 50hz?
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Old 01-04-2015, 03:31 PM   #5
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Thanks all for the answers. Was just checking out boats and one of them was a 50hz boat.

Guess it'd be a pretty big job to convert a 50hz boat to 60hz.
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Old 01-04-2015, 03:32 PM   #6
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Here in Europe all outside work must run on 110 volts by law, so contractors use step down transformers to reduce the voltage from 220/240.

.

Might not be valid for all European countries, I don't think that it is European law. Would be surprised if it was so on the continent...



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Old 01-04-2015, 03:46 PM   #7
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Thanks all for the answers. Was just checking out boats and one of them was a 50hz boat.

Guess it'd be a pretty big job to convert a 50hz boat to 60hz.
The gennie is probably one of the easiest things to convert to 60hz. The rest of the boat elec stuff is the big PITA.
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Old 01-04-2015, 04:09 PM   #8
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I agree with Ski, it might be as simple as setting the engine rpm up. On some the voltage regulator also has to be fiddled with to keep it at 120V.

Almost all motors on a boat can run at 50 Hz or 60 Hz with no problem. Microwave, maybe or maybe not. Coffee maker, water heater or anything resistive, no problem. Chargers probably can also run on both. But inverters are set to make 50 or 60 Hz and may not be easily changed by the user, although if it is a high end inverter like Mastervolt or Victron I'll bet the factory can change it.

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Old 01-05-2015, 07:22 AM   #9
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"Almost all motors on a boat can run at 50 Hz or 60 Hz with no problem."

Here in St. Lucia the domestic supply is 220v 50Hz. I have a US spec boat and run a LARGE transformer in the shore-power line. In my experience, 60Hz air-conditioners work OK on 50 Hz. However the motor that drives the h/p pump on my water-maker, plus the motors on my compressor and bandsaw all get really hot when run on 50Hz. The same motors run much cooler when powered by the boat's generator. YMMV.
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Old 01-05-2015, 09:22 AM   #10
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At a minimum, a really detailed analysis of the particular boat is needed to figure out what would need to change converting a 230V 50hz boat to 240/120V 60hz. Considerations are:

- Generator frequency and wiring. Changing from 50 to 60hz is one aspect, and getting 240/120V is another.

- Will the new 60hz power system be 240/120V, all 240V (unlikely), or all 120V? For the size boat you are talking about, I would expect 240/120V. Now what circuits in the boat will be 240, and which will be 120?

- How does your 240V vs 120V plan correlate with the current construction of the power panel? Will the panel need to be re-segmented to support the two voltages? Will there be a 240 segment and a 120 segment, or will it be set up as split phase 240/120? What breakers will need to be changed throughout the boat, not just in the main panel, but also in all the remote panels scattered throughout the boat?

- Which outlets will need to be replaced?

- What is the wire gauge in the panel and throughout the boat, and will it support the higher current load of 120 branch circuits.

- How will your inverter(s) fit into the system? Which circuits will it power, and which will only operate off shore/gen. What rewiring is required, if any?

- How will the inverter be powered on the AC input side, and are any changes required. For example, if the inverter is 120V input then it may need a balancing transformer on the input side since your shore and gen power are likely to be 240V.

- What equipment needs to be changed out? Inverter? Battery chargers? Washer? Dryer? Hot water heater? Water maker? AirCon system? Heating system? Blower fans (there are lots of them between the equipment spaces, heads, and galley). If you are trying to get a boat that will primarily live in a 60hz world, then all appliances should be changed unless they are explicitly rated for both voltage/hz environments. Also note that appliances may need to change due to the frequency change, and other because of the voltage change. Both need to be checked.

- What other appliances need to be changed? Microwave? Fridge? Freezer? Counter-top appliances? Dishwasher? Trash compactor? Oven? Cooktop?

- What electronics will be impacted? After the switch will they be running off 240 or 120, and are they appropriately rates?

- Now what about shore power? Will plug ends and shore power cords need to be changed? What about breakers, isolation transformers, and power distribution?

Any one of these items could be really easy, or really hard. It all depends on the specifics of the boat.
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Old 01-05-2015, 09:22 AM   #11
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Might not be valid for all European countries, I don't think that it is European law. Would be surprised if it was so on the continent...

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In The Netherlands on shipyards inside steel constructions like tanks, for safety reasons, you are only allowed the use of max. 48V Direct Current.

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Old 01-05-2015, 09:32 AM   #12
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"Almost all motors on a boat can run at 50 Hz or 60 Hz with no problem."

Here in St. Lucia the domestic supply is 220v 50Hz. I have a US spec boat and run a LARGE transformer in the shore-power line. In my experience, 60Hz air-conditioners work OK on 50 Hz. However the motor that drives the h/p pump on my water-maker, plus the motors on my compressor and bandsaw all get really hot when run on 50Hz. The same motors run much cooler when powered by the boat's generator. YMMV.
Many, perhaps most electric motors designed for 240V/60hz will run on 230V/50hz. Lots of people do it and get away wit hit, but it doesn't mean it's a good idea. In fact, it's a bad idea, akin to running your diesel in a constant overload condition.

Given any particular electric motor, if you run it at a lower frequency, you need to correspondingly lower the voltage. Conversely, if you run at a higher frequency, you need to take up the voltage. So an air conditioner designed to run at 240V/60hz can be run be run at 50hz, but you need to cut the voltage down to 200V. Otherwise the motor will be stressed and run hot, as you observed. If you read the fine print on the name plates and spec sheets for Dometic air con systems, they tell you this.
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Old 01-05-2015, 09:49 AM   #13
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Why not add a Shorpower frequency converter and you won't have to worry about 50 or 60 hz again? You could take your Nordy almost anywhere.

Atlas Marine Systems - Frequency Converters, AC/DC Switchboards, Engineering & Design Services
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Old 01-05-2015, 09:49 AM   #14
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Many, perhaps most electric motors designed for 240V/60hz will run on 230V/50hz. Lots of people do it and get away wit hit, but it doesn't mean it's a good idea. In fact, it's a bad idea, akin to running your diesel in a constant overload condition.

Given any particular electric motor, if you run it at a lower frequency, you need to correspondingly lower the voltage. Conversely, if you run at a higher frequency, you need to take up the voltage. So an air conditioner designed to run at 240V/60hz can be run be run at 50hz, but you need to cut the voltage down to 200V. Otherwise the motor will be stressed and run hot, as you observed. If you read the fine print on the name plates and spec sheets for Dometic air con systems, they tell you this.
Not agree with this statement, these motors not run in an overload condition, they actually run in an under-load condition, this has nothing to do with the supplied voltage just the Hz.

The general guidelines for operating 60 Hz motors on 50 Hz systems relate to the fact that the volts per cycle have to remain constant with any change in frequency. Also, since the motor will operate at only five sixths of 60 Hz speed the output horsepower capability of 50 Hz is limited to a maximum of five sixths of nameplate H.P.

These motors can be over-loaded simply because they not have adequate H.P. anymore for their task, bringing the supplied voltage down just makes the situation worse.

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Old 01-05-2015, 10:15 AM   #15
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Its all about the de-rate factor, the given 200 volts is found as follows;

240v * (50Hz/60Hz) = 200v this not mean you should run this motor on 200v, it means on 50Hz it has the performance as of running on 200v.

Example; to replace a 1 kw 240v 60Hz motor to run on 50Hz you need to replace it with a 1kW * (60Hz/50Hz) = 1.2 kW 240v 60Hz motor.

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Old 01-05-2015, 11:37 AM   #16
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Its all about the de-rate factor, the given 200 volts is found as follows;

240v * (50Hz/60Hz) = 200v this not mean you should run this motor on 200v, it means on 50Hz it has the performance as of running on 200v.

Example; to replace a 1 kw 240v 60Hz motor to run on 50Hz you need to replace it with a 1kW * (60Hz/50Hz) = 1.2 kW 240v 60Hz motor.

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I think we are talking about different things. One is about what power output you will get if you operate a motor at a different frequency. And that you may end up with an under-powered motor for the application. I agree with that.

But I do believe it is correct that a 240V/60hz motor should be run at 200V/50hz. The issue, as I understand it (and I don't claim to be an expert by any means) is that the back EMF, which is what resists unbounded current flow through the motor windings, is proportional to frequency. As the operating frequency drops, so does the back EMF. When the back EMF drops, current flow increases and windings run hotter. If the frequency is dropped enough, there is a complete collaps of the back EMF and you end up with a short cuircuit through the windings. After all, to DC current, and AC motor is a dead short.
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Old 01-05-2015, 12:07 PM   #17
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Can't really make simple statements on this. AC induction motors are complicated and their behavior at different frequencies and voltages is complicated. Add into that the varying load. And start/run capacitors.

True that lower frequency will cause amps to go up based on the inductance being constant. Lower volts and amps will go down. But also will motor output. If running near capacity at 60hz, motor will increase its pole slippage and amps then go up. It may approach stall, in that case amps go through the roof and thats when things burn up.

Biggest deal is refrigeration compressors. Refrigerant valving means pressure across machine is probably near constant, then motor torque is constant. But available output is lower on lower freq, so motor is closer to stall. How close?? Only mfr will know. Running amps can be metered, and that gives a good hint. If amps go way up, trouble is ahead. Amps stay the same or small increase, should be ok.

Blowers and pumps should be ok as their load will drop with lower rpm. But as posted above, there are examples of them burning up. Ammeter is your friend to check this.

Induction motors look simple. But they are not. I studied these things in school and in industry, and the more I studied the more I realized how little I knew!!!
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Old 01-05-2015, 05:38 PM   #18
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BTW the boat in question is a 64 Nordhavn and has a Atlas system already. But the boat is native to 50Hz.
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Old 01-06-2015, 07:39 AM   #19
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From 50Hz to 60Hz

Would it make sense to leave it 50Hz and just deal with it?
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Old 01-06-2015, 08:46 AM   #20
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Would it make sense to leave it 50Hz and just deal with it?
I was going to reply just that yesterday but have been thinking about it.

Looked up the boat you mention on YW an could not find the name of the genny nor capacity so it isn't easy to answer your question. My suspicion is most will run at 60 or 50hz and there should be a switch or jumpers to control that. But if everything else is native 50hz and you have the Atlas system, why would you want to change? The only reasons I could think of is it all the outlets on the boat are wired to foreign standards and you want to change them out to use US appliances and the like. Seems like a much more complicated issue than simply changing the generator.

I saw one smaller Nordy on YW which was $50K below market and one of the rationale was it was 50hz native and had to be rewired. Don't recall if it had the Atlas system. It didn't sound like it was a cheap fix. Couldn't find it on YW yesterday so it might have sold or been removed from the market.
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