Inverter wiring

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rascacio

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I want to wire the 230v ac output from an inverter through a rotary heavy duty switch and then into the mains consumer panel on board.

I am assuming that this will be ok so long as there is not another source of AC power in the circuit.

If connecting to shore power or starting up my genny I would isolate the inverter via the switch.

Does anyone know if this set up is ok or if not what is the best way to go about it ?

I'd like to be able to use the on board sockets at will when at anchor or without shore power, without the inevitable extension leads snaking around the boat. (Well it's SWMBO really, extension leads don't bother me that much !!)
 
VicS said:
Ensure that the switch is a "break before make" type.
Click to expand...

Thanks VicS. Just to clarify something, I will only be wiring the inverter through the switch, the shore power connections will remain the same i.e directly connected to the board.

The switch will be off when shore power is connected. So upon leaving port shore power is disconnected and the switch is closed to connect the inverter to the board and the inverter switched on. Does all this sound correct ? Obviously the products you highlighted would do the job, it's just that I'm trying to keep the costs down.

Is there anything else to think about ?

Thanks again.
 
I would use a change over switch. Without it would be possible to have inverter and shorepower on. You know the saying: if its possible one day it will happen

I have no idea if the inverter will withstand mains power connected to its output when it is not running.

See what others think.

it's just that I'm trying to keep the costs down
Click to expand...
small leisure battery, a little solar panel, a bit of charging from an outboard and no mains power at all. That'll keep the costs down. :D
 
I think that the regs state that the two supplys must be interlocked so that there is no way of having the two supplies on together.

Since there is no means oy sychronizing the frequency the iverter would probally go to heaven and the shore power interuped rather violently. I stand to be corrected.
 
I think that the regs state that the two supplys must be interlocked so that there is no way of having the two supplies on together.
Click to expand...
Yes you are absolutely on the button.
Dont know why I didnt look myself

ISO 13297 says:

4.6 Individual circuits shall not be capable of being energized by more than one source of electrical power at a
time. Each shore-power inlet, generator or inverter is a separate source of electrical power. The transfer from one
power-source circuit to another shall be made by a means which opens all current-carrying conductors, live and
neutral, before closing the other source circuit, prevents arc-over between contacts and is interlocked by
mechanical or electromechanical means. Both current-carrying conductors, live and neutral, shall be broken
simultaneously when changing power sources.​
 
Mains switching

The simplest and most foolproof arrangement is to have a board with 3 sockets on it. One from Inverter one from mains shore power lead and one from generator. Have a plug on a short wire to the boat wiring that can plug into any one of the sockets.
As said any connection of 2 sources will result in much smoke and destruction. Imagine having 2 12v batteries that you want to wire in parallel. You don't know which is pos and which is negative terminals. You can end up with 2 x12v batteries in parallel or two 12v batteries in series with a short circuit across the 24v. That is what happens with AC sources in parallel. +ve and -ve are constantly changing usually at different rates so worse case you end up with 500VAC with a short circuit.
Not worth the risk. be careful olewill
 
Thank you gentlemen. It would seem that my original question has been clarified, that is, the rotary changeover switch is more than adequate to switch supplies but with the idiot factor thrown in i.e. forget to do it !! = disaster.
Therefore with adding the single plug from each supply to one receiving plug on the board I should never have a problem with the sequence, well theoretically that is !!!

Many thanks.
 
I have s 3 way + off 3 pole selector switch to select between shore power, inverter and generator + off.

I have also included RCD's in each incoming circuit.

The earth connection for the inverter and generator must be connected to the neutral at the inverter and generator but not the incoming shore as this is done at the substation transformer. If this is not done the RCD's will not work.

The third pole on my selector is to switch the earth, I know earth should normally not be switched but the need to connect earth and neutral at inverter/generator makes this necessary.

Below is my mains panel setup the third one down is my mains selection panel.
 
Last edited by a moderator:
I am to be fitting an inverter in the not too distant future. I'm mostly concerned about being able to put the unit in the cabin with adequate cabling. Given that it will be about 3m from the batteries, so I guess 4m of cable, I assume that's going to have to be cable the size of my little finger? 24V 600W continuous. That sounds like I might do better to fit the device in the engine bay next to the batteries and fit a semi-permanent mains cable and socket. Any advice on the choice? Mains cable is cheap and I have some, the other stuff is many penny and would need to be bought in.
 
Andrew_Fanner said:
I am to be fitting an inverter in the not too distant future. I'm mostly concerned about being able to put the unit in the cabin with adequate cabling. Given that it will be about 3m from the batteries, so I guess 4m of cable, I assume that's going to have to be cable the size of my little finger? 24V 600W continuous. That sounds like I might do better to fit the device in the engine bay next to the batteries and fit a semi-permanent mains cable and socket. Any advice on the choice? Mains cable is cheap and I have some, the other stuff is many penny and would need to be bought in.
Click to expand...
The engine bay may be too hot for the Inverter - They like to be cool.
With regards to connecting the inverter to the boat sockets, I simply run the mains cable up to the location of my shore power socket, then plug in the inverter when I remove the shore power lead - simple, cheap and safe.
 
Exactly the method we used on the previous boat - the shorepower inlet was in a locker - so it wasn't difficult to unplug the inverter then plug in shorepower ... then reverse it.
 
I've used the same sort of arrangement, I can only plug the inverter into the shorepower socket by removing the shorepower cable, impossible to have both connected at the same time. I also have a label on the cable reminding me to switch off the charger, the only potential weak point in the method I use.
 
I admit it, it had never occurred to me to simply plug the inverter into the shore power socket. That's utterly brilliant in its simplicity:-) And so noted on the battery charger, I think a label on the inverter plug at the shorepower socket end "Disconnect Battery Charger" should cover it.
 
Andrew_Fanner said:
I admit it, it had never occurred to me to simply plug the inverter into the shore power socket. That's utterly brilliant in its simplicity:-) And so noted on the battery charger, I think a label on the inverter plug at the shorepower socket end "Disconnect Battery Charger" should cover it.
Click to expand...

I'm not clever enough to think of any other solution! Simple, that's me all over. Honestly, though, I simply couldn't see any other way to do it, being a numpty when it comes to circuits and as I had just fitted the shorepower socket, I thought that's what you did...............now if I can just get up the courage to try the gas oven and grill.......................:D
 
Kiss

I think the separate plugs is a great idea. Simple and foolproof.

Definitely need a label on the charger though as it's probably the only weak link in the set up.

My inverter will be located almost next to the charger so I should remember but, as with all things it's best to have a back up just in case.(BIG Label) You never know who'll be helping and simple instructions are simple instructions.
 
>>>
I'm not clever enough to think of any other solution! Simple, that's me all over. Honestly, though, I simply couldn't see any other way to do it, being a numpty when it comes to circuits and as I had just fitted the shorepower socket, I thought that's what you did...............now if I can just get up the courage to try the gas oven and grill.......................
>>>

He he, that's a doddle. Can't check for lecky leaks with a match yer see:-)
 
Just one proviso. You should never be able to have a plug with exposed live pins. So the connector on the end of the shore line should be a socket, as should the connector from the invertor. The connector to the boat's wiring should be a plug.
 
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