Mahe 36: Electrical - 110 and 220 Volt Systems

[DotDun]

Originally Posted by MIRELOS

http://www.cruisersforum.com/forums/...ml#post419184\

I own a Eleuthera 60 and have the same problem wrote to FP asking if I could change the 10 amp to a 16amp and the 6amp to a 10 amp. They responded that the wiring is 1,5mm(squared), what that means in European electrical code I don't know since I'm only familiar with US code, and therefore they do not recommend that I do it. FP is of course never very helpful unfortunately.
Good boats, yes, good service, no.
Any ideas?

Cross reference for mm2 to awg at:

The Mueller Group, Inc - MM2 to AWG Conversion Charts

I would suggest you hire a qualified marine electrician.

IMO, if the in-place wire size will deliver the power you require, no need to change it. If the wire size is too small, you have no choice but to change it. The measurement system used to describe the wire is no reason to change the wire. IOW, your 1.5mm2 wire is equal to ~16awg, it should carry a 10 amp breaker and deliver 1200 watts @ 120v. If you need more than 1200 watts on that circuit, change the wire and breaker to a bigger size.

You boat was wired to European standards where a 10a 230v circuit delivers 2300watts. I don't understand why FP isn't very helpful, they didn't invent the physics associated with electric distribution.

[MIRELOS]

Thanks, that is most helpful.
Now to get the breaker.

[Clipperton]

Regrading this 16 vs 6 amp breakers, here is what I have done.
I called FP and they sent me 4 breakers. Theys are the MFN 716.

I ordered 4 because I have 2 full electrical systems. Initailly one is 110 and the other is 220.
For the 110, it is now running the two new breakers and my nespresso and other 1500 watts stuff works well. My girlfriend is now super happy with the hair dryer at full speed ;-)
For the other 220v system, i will just have to switch the dock plug to a US one and put the 16 amp breakers. The associated battery charger will always remain off.
In the boat will just use the outlets. Like that I have a full double electrical system. Very useful for the winter when temperature drops and it is pretty useful to have some heaters at full speed.
Changing the breakers was simple. 15 minutes.

[Seastream]

Hello, folks:

I'm new to this forum; please excuse me if I'm not posting in the right place. I live in NH and am in Tortola, about to buy a 2008 FP Mahe 36. Sweet boat, good condx, but for whatever reason was built without shorepower. I'm fairly good with AC power but am not an electrician. Knowing it's harder to integrate features post construction, should I add it myself or pay a yard to do so, to avoid 'do overs'?

[Cotemar]

Sea stream,

There is only four plugs and a hot water heater to be wired to a small breaker box and battery charger.

I do not know your skill set, but I could do this electrical system myself.
Plenty of large race ways to snake the wires.
I could send you the wiring diagram.

[Seastream]

Cotemar: Sounds within my skills. If you could send me the wiring diagram, that would save me digging thru all onboard to get the FP manuals I'm told are there. Thanks!

[Cotemar]

Seastream,

Turns out that FP did not give us the 110 volt wiring diagrams.
I made one up for us to use.

See attached pdf file.

[Rufduck]

Greetings,
My new 2007 Duo Mahe 36 has European 230X50hz shore power. Need to convert to US 110X60hz.
FP advised that they do not use different wire for the two volt/Hz.
I have separate charger and inverter. The charger can use either voltage so will replace the inverter which is 230vac only.
Anyone done this? Pitfalls? Cautions? Suggestions.

Cheers, RufDuck

[DotDun]

Originally Posted by Rufduck

Greetings,
My new 2007 Duo Mahe 36 has European 230X50hz shore power. Need to convert to US 110X60hz.
FP advised that they do not use different wire for the two volt/Hz.
I have separate charger and inverter. The charger can use either voltage so will replace the inverter which is 230vac only.
Anyone done this? Pitfalls? Cautions? Suggestions.

Cheers, RufDuck

You'll need to determine the power requirements in order to determine what shorepower size to chose (30a, or (2) 30a, or 50a).

The wire for the branch circuits is fine as are the branch circuit breakers. You'll need to change the shorepower inlet/cord, then the receptacles. If the original shorepower is 230v/16a, you'll need to change the wire all the way to the circuit breaker box (to support 30a or 50a) along with the main breaker. Strongly suggest using a ELCI/RCD main breaker.

[Rufduck]

Thank you,

I just presumed the shore power cord was 12AWG or equivalent but will check every wire size and proceed accordingly.
A bit confused by your answer tho. Are you saying the breakers in the 230V panel for the branch circuits are adequate? I would think they would be half the amperage necessary for 110.

There was a post where the fellow put in a parallel 110v system and retained the original 230X50 but disconnected it. This appeals with only a bit more work. The only part missing for me is the inverter which i must replace anyway.

Our HV needs are minimal but will size the system for heavier loads so it won't need an upgrade later.

Any idea what the "typical" inverter size is or is that similar to asking what color is a car? At present the House Bank is 3 somethings. Doubt they are original.

Do you have any idea if there any other Mahe 36s in the Northwest? It would be so helpful if there was another I to which could compare.

Cheers,

Rufduck

[DotDun]

Originally Posted by Rufduck

Thank you,

I just presumed the shore power cord was 12AWG or equivalent but will check every wire size and proceed accordingly.
A bit confused by your answer tho. Are you saying the breakers in the 230V panel for the branch circuits are adequate? I would think they would be half the amperage necessary for 110.

There was a post where the fellow put in a parallel 110v system and retained the original 230X50 but disconnected it. This appeals with only a bit more work. The only part missing for me is the inverter which i must replace anyway.

Our HV needs are minimal but will size the system for heavier loads so it won't need an upgrade later.

Any idea what the "typical" inverter size is or is that similar to asking what color is a car? At present the House Bank is 3 somethings. Doubt they are original.

Do you have any idea if there any other Mahe 36s in the Northwest? It would be so helpful if there was another I to which could compare.

Cheers,

Rufduck

A circuit breaker protects the wire, not the appliance. If your existing wire handles 16a (2.5mm2), the existing 16a breaker will protect it adaquately whether it's 230v or 120v. Your are confusing amperage with power. When you cut the voltage in half, the power delivery capability of the circuit is cut in half, given the same current (amps) draw. Hence, a 230v/16a circuit can deliver up to 3680va, whereas a 120v/16a circuit can only deliver up to 1920va.

A parallel system is your choice, in the end, it usually comes down to $$. It would be hard for me to find justification as I have no plans to buy appliances from both continents.

Inverter is another personal decision. In my experience I wouldn't put in anything smaller than 2kw (as I face upgrading a 1kw decision from 12 years ago). This will support appliances like a microwave when it doesn't make sense to fire up the genset for 3 minutes to heat leftovers.

[Rufduck]

Understand. I just presumed a branch circuit that is on a 5 amp breaker 230v will supply power to a given set of expected appliances. To run a similar set of appliances at 110v, wouldn't the circuit need a 10 amp breaker to be comparable. A fan needs X watts, a light needs Y watts, a microwave needs Z watts all at 230 V. Would they not need twice the amperage to reach the same wattage?
Been smelling boat polish all afternoon. If I'm being dense just say "think about it some more".

The boat came with a 500 watt 230X50hz inverter and the PO regularly ran it too hot for some of his needs. So, thinking 2kW 110v also.

Thanks again,

Rufduck

[DotDun]

Originally Posted by Rufduck

Understand. I just presumed a branch circuit that is on a 5 amp breaker 230v will supply power to a given set of expected appliances. To run a similar set of appliances at 110v, wouldn't the circuit need a 10 amp breaker to be comparable. A fan needs X watts, a light needs Y watts, a microwave needs Z watts all at 230 V. Would they not need twice the amperage to reach the same wattage?
Been smelling boat polish all afternoon. If I'm being dense just say "think about it some more".

The boat came with a 500 watt 230X50hz inverter and the PO regularly ran it too hot for some of his needs. So, thinking 2kW 110v also.

Thanks again,

Rufduck

First, I hope your example of a 5a breaker is hypothetical. I've seen 10a and 16a branch circuits on EU wired boats, but not 5a. Most receps are on 16a circuits whereas direct wired appliances may be on 10a.

Second, if you change from a 5a breaker to a 10a breaker when the wire is only rated at 5a, you'll chance burning your boat down.

You are correct that the same wattage draws twice the amps from a 120v circuit as it does from a 230v circuit. But you don't change just the circuit breaker, you change the wire also.

You need to inventory what you have and decide if that will support your new 120v requirements. If in fact your EU branch circuits are 16a, which I suspect to be the case, you'll have to decide if you need to support appliances that pull more than 1920va for each of those in-place circuits. Household recep branch circuits in the US are 15a or 20a, so 16a is very useful at US voltages. Depending on how the circuits are wired, if multiple receps are shared on the same circuit, you may not be able to run multiple large appliances at the same time, which is a tragedy only in the minds of landlubbers!

Technically, you need to think about volt-amps (or max input current) instead of wattage. Most appliance wattage ratings are referring to their output not the input. Example: A 700 watt microwave can very easily require 1200va input to produce 700watt output. VA and watts are calculated the same = amps times volts. A 1500watt hair dryer will pull pretty close to 1500va at it's input. Most appliances will list a max input current, use that to determine load on the circuit, not the wattage rating.

[rabbi]

Originally Posted by Rufduck

Understand. I just presumed a branch circuit that is on a 5 amp breaker 230v will supply power to a given set of expected appliances. To run a similar set of appliances at 110v, wouldn't the circuit need a 10 amp breaker to be comparable. A fan needs X watts, a light needs Y watts, a microwave needs Z watts all at 230 V. Would they not need twice the amperage to reach the same wattage?
Been smelling boat polish all afternoon. If I'm being dense just say "think about it some more".

The boat came with a 500 watt 230X50hz inverter and the PO regularly ran it too hot for some of his needs. So, thinking 2kW 110v also.

Thanks again,

Rufduck

Yes, at 110v you would need wires and breakers rated at twice the amperage rated at 220v.
But your wires are not able to carry more than 16A and may burn down the boat if you use bigger breakers. Always use breakers suited for the wire size!

If you need more than the 16A you need to re-wire. If you can live with the 16A you can keep it.
16A @ 110v is over 1500w which in my view is good enough except for electrical heating.

We have 1000w inverter on our boat which is enough for microwave, bread maker or power tools. And even 1000w is really hard work for the batteries.

[Jef & Marin, Netherlands]

Hi,
Cotemar has upgraded his 110V Mahe 36 to higher circuit breaker amperage, around 2010. Problem was that they are only 10A. The wires are adequate for handling larger current, he checked that. The wiring loom has also been developed for 110V use.
There might be a post from him about this.
I supplied him with 16 or 20 A circuit breakers of the same series, which are only available in Europe. These are a drop-in replacement. I ordered them in the Netherlands and sent them to Cotemar, for him and another Mahé owner. In the Netherlands it was a special import order since this specific version is normally only supplied in France.
Ideally, you would find a friend in France or elsewhere in Europe who orders or purchases them there locally and sends them to you.
I can not help you with this anymore since we are not in Europe anymore.

I seem to remember that Cotemar kept the main circuit breaker original. Please try to find a post from him, or ask him.

Regarding the inverter, I would suggest that you check the permitted discharge current of your batteries. 2000 Watts will be consuming close to 180A. This is a discharge of around 0.6C. C is the Ampere hour battery capacity of your battery.
Drawing such a large current from a small battery could damage them or reduce life.

At this moment in time I would always choose LiFePO4-batteries. They can handle that kind of discharge easily. In my view lead acid batteries are obsolete.