AC wiring advice needed

[roland stockham]

Hi, want to check this with some of the experts here as I am still faily new to split phase N American systems.


What I am proposing is to install a low frequency inverter charger so that I can add 120v circuits to a boat originally built for European 240v. I want to keep the 240v so I can use European power tools and run the water heater.


I would change the distribution box and supply the sockets and water heater by connecting the 'live' wire to L1 and the 'neutral' to L2 thus creating a 3 wire 230v hot/hot/earth. Am I creating a problem here as the 'neutral' will not be grounded at the inverter as it would have been in the original system?


The other issue is that the inverter has a transfer switch to allow it to act as a charger and pass through current when connected to shorepower. The data sheet says that it can connect to 120v so that would be hot/neutral/ground via a 3pin 30a receptacle on the dock. The wiring diagram shows this connection as hot/hot/earth with no neutral connection. but this would be for 50a 4 wire 230v dock receptacle not 110v. Can't see how this would work Do I need to get the 230v version and change my shore power inlet to a 50a 4 pin lead in order to get 230v?


I am rarely going to be on shorepower however I would like to be able to run from a 120v generator both for using tools and battery charging. One solution is to get a transformer with a 120v primary and center tap 230v secondary to convert from 3 wire inlet to 4 wire at the inverter input.


The inverter is like this one https://www.globalindustrial.ca/p/el...hoCU3MQAvD_BwE


Many thanks for thoughts and comments

[john61ct]

I would just run the two circuits off two different inverters, and put in a universal world power charger.

[roland stockham]

Originally Posted by john61ct

I would just run the two circuits off two different inverters, and put in a universal world power charger.

Yess that would be one solution but would more than double the cost and need 3x as much room. Might simply use the inverter for power and have a separate charger as this provides better isolation, not a big fan of 'pass through' devices.

[john61ct]

http://www.skoolie.net/forums/f10/ne...ing-27366.html

[smac999]

are you trying to add some 120v 60hz circuits to an existing 230v 50hz boat and have both available? depending on where you go?

if you want to run a few 120v outlets. and charge with a 120v input occasionally. then make a whole isolatoed system. 120v shore plug to 120v main breaker to 120v inverter / charger to 120v panel to 120v outlets. all with 3 wire hot / neutral / ground. don't try to mix and match stuff.

or are you trying to converter the entire boat to 240v 60hz? and never go back to 230v 50hz?

[Snore]

Of course since you will likely only use 2 or 3 plugs, why not just get travel adapters? $5 each and the plug is adapted to US power.

[Djarraluda]

Sounds as if it could go pear shaped, quickly! Be very cautious, because Single phase is part of the 3 phase system. Put another way, 230V is Phase to Neutral, but 400V is Phase to Phase of the same 3 phase, 4 wire system.
Independently, we have the frequency, 50Hz for most, 60Hz for American.

If you apply 120V to a resistance heater such as the clarifier, or an electric kettle, it will pull a lot higher amperage than design and this may work but will stress the terminals. If you apply the wrong frequency to a system, it may work at a different speed, or it may go "poof!".

Make certain you follow things through properly, the separate inverter and 120V outlet may be preferable.
Roger

[Scrimshaw4]

I suggest that you have a qualified marine electrician design and do the installation. Otherwise if the system goes "poof" and starts a fire you might not only be risking injury, etc., but you might not be covered by your insurance. Just a thought ...