How can I run a European system (50hz 240v) in America (60hz 120v)?

[Auspicious]

Originally Posted by Sailing4Jesus

However, on the other hand The United Nations cannot even make up their minds if they need to Pee or not. So all member nations would save many billions if we abolished The Worthless United Nations, as they are a worthless as tits on a boar hog.

Sorry to digress so long after the post. The United Nations does a lot of good. For example the ITU and IMO, both UN agencies, are why we have full license reciprocity worldwide for radios (VHF, HF/SSB, and satellite). The IMO is why your papers work as registration on your boat. Like most large governmental and quasi-governmental organizations there is bloat. "Worthless" is a gross overstatement.

[SV Bacchus]

Originally Posted by Dockhead

My generator can be switched over to produce 8kW at 110v/60hz at 1800RPM, from its normal 6.5kW at 230v/50hz at 1500RPM. You just change the constant speed diesel governor setting and connect the generator head differently. There are instructions in my manual. With a constant speed generator, the frequency is determined by the governed engine speed.

Gotcha, so my thoughts were right, it is the speed of the armature. Thanks for the confirmation.

I wasn't thinking so much from genset on a boat as I was when converting shore power. Example, we are US outfitted boat at 110/60. But here in Grenada they are 220/50 and I was wondering if there is a way to change that Hz?

[s/v Jedi]

Originally Posted by SV Bacchus

Gotcha, so my thoughts were right, it is the speed of the armature. Thanks for the confirmation.

I wasn't thinking so much from genset on a boat as I was when converting shore power. Example, we are US outfitted boat at 110/60. But here in Grenada they are 220/50 and I was wondering if there is a way to change that Hz?

And remember, when you change rpm from 1,500 for 50Hz to 1,800 for 60Hz, you also gain 20% power, i.e. a 5kW 230V/50Hz genset becomes 6kW 230V/60Hz. Many also allow the voltage to be changed to 240V as well. Often the voltage regulator has jumpers for voltage and frequency besides the governor adjustment

[Jubilee39]

Originally Posted by s/v Jedi

And remember, when you change rpm from 1,500 for 50Hz to 1,800 for 60Hz, you also gain 20% power, i.e. a 5kW 230V/50Hz genset becomes 6kW 230V/60Hz. Many also allow the voltage to be changed to 240V as well. Often the voltage regulator has jumpers for voltage and frequency besides the governor adjustment

Had a service call on a French charter boat in St Martin. 5 KW genset with many hours would not run watermaker. Set was at 50HZ. I raised frequency to 60HZ and ran fine. French captain had me lower back to 50 HZ and then slowly raise frequency until WM would run. Explanation" this is a French boat and it runs 50HZ" BTW I tested rest of equipment and most where 50/60 capable
EMCM(ss) retired

[Auspicious]

Changing frequency is usually pretty hard and/or expensive. A company I worked for had a motor-generator set in our lab for testing equipment heading to Europe. It was huge and load and hideously expensive.

s/v Jedi's approach of paired inverter/chargers (I/C) works. You can do the same with separate battery charger that supports 50/60 Hz and an inverter for your electrical flavor of choice. The underlying value of his approach is redundancy if the units are identical. The cost is about 40-50% more money.

[john61ct]

Not for a mostly DC boat that uses very few / small AC load devices, then it's very much the cheapest way to go.

Those running aircon, clothes driers, electric ovens & HWS, yes, must pay for their sins.

[sailcrazy]

And don't forget, with all this talk of paired inverters, etc, that IF you need sinusoidaL ac power (vs square wave) for your "stuff", those come a lot dearer.

[john61ct]

Again, not so much with a small low-wattage circuit.

[s/v Jedi]

Originally Posted by Auspicious

Changing frequency is usually pretty hard and/or expensive. A company I worked for had a motor-generator set in our lab for testing equipment heading to Europe. It was huge and load and hideously expensive.

s/v Jedi's approach of paired inverter/chargers (I/C) works. You can do the same with separate battery charger that supports 50/60 Hz and an inverter for your electrical flavor of choice. The underlying value of his approach is redundancy if the units are identical. The cost is about 40-50% more money.

You are correct. The big change in my diagram is that it diverts from the more integrated setups that manufacturers push, like parallel operation, an output that is not powered during inverter operation, transfer between genset and shore power etc. This simplification allows flexible choice of equipment like a simpel charger and inverter like you describe.

My latest diagram I posted here, shows two groups of breakers where one can select a source for each group. For me, the second group is just the watermaker. I’ll take this opportunity to explain this setup:

For normal, underway or at anchor operation, input select is on genset, breaker for both inverter/chargers are on, group A is on source inverter/charger 1 and group B (watermaker) is on source “bypass”. The watermaker is now powered just like an A/C unit or water heater: by genset only. Batteries are charged at double charge current.

When the genset fails, the group B source is changed from bypass to inverter/charger 2. The engine runs to provide DC power to the battery bank, which is used by inverter/charger 2 to power the watermaker. At the same time, group A can use power as well, as long as alternators, solar and batteries hold up to the load.

[Pansatonic]

Originally Posted by s/v Jedi

Here’s my latest diagram, which probably is the final revision

I am intrested in your GFI protection devices placements and your design with reference to the earth/neutral bound. I assume you are using dual pole switches/breakers.

[s/v Jedi]

Originally Posted by Pansatonic

I am intrested in your GFI protection devices placements and your design with reference to the earth/neutral bound. I assume you are using dual pole switches/breakers.

I ditch the neutral and ground wires from shore as soon as possible. In case of the ground, this happens either at the isolation transformer or the galvanic isolator. The neutral is dropped at the isolation transformer or right after the surge suppressor. This means that all input from that point is 240V either non-polarized from the transformer or the L1-L2 conductors from the 120/240V 50A shore power. Generator neutral is not connected either.

From there on, AC breakers are double pole. For 120V service, a new neutral is made with an auto transformer, but it is not grounded.

I do have some GFCI outlets but they can’t trip as there is no other return path. Of course it makes double pole breakers a requirement as the “neutral” in the outlets is hot.

[Pansatonic]

Originally Posted by s/v Jedi

I ditch the neutral and ground wires from shore as soon as possible. In case of the ground, this happens either at the isolation transformer or the galvanic isolator. The neutral is dropped at the isolation transformer or right after the surge suppressor. This means that all input from that point is 240V either non-polarized from the transformer or the L1-L2 conductors from the 120/240V 50A shore power. Generator neutral is not connected either.

From there on, AC breakers are double pole. For 120V service, a new neutral is made with an auto transformer, but it is not grounded.

I do have some GFCI outlets but they can’t trip as there is no other return path. Of course it makes double pole breakers a requirement as the “neutral” in the outlets is hot.

I am not sure i understand, where are you neutral/earth bounded then? Earth leakage detection only works if the neutral conductor is connected to the earth conductor.

[s/v Jedi]

Originally Posted by Pansatonic

I am not sure i understand, where are you neutral/earth bounded then? Earth leakage detection only works if the neutral conductor is connected to the earth conductor.

I don ‘t have a grounded neutral, it’s called a floating system. Because neither of the two conductors is grounded, you can grab either one with one hand and ground with the other and nothing happens. So you’re right, earth leakage doesn’t work but you don’t need it because ground is not a return path

If you have simple 120V wiring, all you need is an isolation transformer and keep ground and neutral away from all the rest of the boat. It does require double pole breakers though.

[Pansatonic]

Originally Posted by s/v Jedi

I don ‘t have a grounded neutral, it’s called a floating system. Because neither of the two conductors is grounded, you can grab either one with one hand and ground with the other and nothing happens. So you’re right, earth leakage doesn’t work but you don’t need it because ground is not a return path

If you have simple 120V wiring, all you need is an isolation transformer and keep ground and neutral away from all the rest of the boat. It does require double pole breakers though.

A normal return path can be touched UNTIL its not normal any longer. How will you know when its not? GFCI as an detection device will not tell you.

Why is a design where potential life saving fault detection can not be used, a good thing? (relating to your thumbs up). Truly curios.

[wingssail]

Originally Posted by Pansatonic

A normal return path can be touched UNTIL its not normal any longer. How will you know when its not? GFCI as an detection device will not tell you.

Why is a design where potential life saving fault detection can not be used, a good thing? (relating to your thumbs up). Truly curios.

What I learned through experience, rather early on with our inverter/charger system, is that when the neutral is grounded it makes every outlet box, every appliance case, every grounded bit of metal on the boat into a potential shock hazard. Why is that the situation with a grounded neutral? Because the neutral is the normal return path for AC electricity. If, at anywhere in the circuit between the boat and the shore power, including all the way down the dock to the shore ground and neutral, if a resistance or poor connection exists, with a grounded neutral then a voltage potential exists at the grounded metal cases on the boat.

If you happen to brush against an outlet plate or touch a metal appliance case for example, or other metal which is grounded and now hot, while any other part of your body is in contact with the boat's DC grounding system (to the sea water) such as the mast, then your body provides a path for the AC to get to ground. I just don't like living in a space encircled by potentially hot, exposed, bits of metal and I got damn tired of little tingles on my leg every time I brushed an outlet plate, or in my hand every time I picked up the toaster.

And, if you have a grounded neutral and connect the AC ground (green) to the ship's DC ground, then you have a direct, constant, path for AC to flow into the sea, or, if your wiring and the shore power connection is excellent, then your ship's ground system provides a path for stray electricity from an other nearby boat to flow to ground through your boat. In either case this is an electrolysis situation and your bonded skin fittings become sacrificial.

With a floating neutral a short in any appliance to the case is instantly routed to the ground and will trip a breaker. Yes, this is not as instant as a GFCI triping, but in my opinion a floating neutral is, overall, safer.

I understand there are differences of opinion on this.