Targa 40 Inverter

[LUNA]

Ok I have just tumbled this

You are running the inverter. This is probably a modified sine wave variety.

You are now energising the 240v circuit with dirty 240v.

The charger turns on and off using an electronic switch not an actual switch. So when it is off it is not really off

The dirty supply is then causing it to buzz

The inverter should be installed in such as way that if can’t power the charger. You can’t use the batteries to generate 240v which the goes to a charger to charge the very same batteries that are powering the inverter

You should have a true dual pole change over switch anyway to change over the 240v. You should get one with 2 dual poles so you can also isolate the charger and given how it is installed it will never be possible for the charger to be on when the inverter is selected.

Its a Pure sine Wave Inverter . ive put my mutimeter on live wire on junction box in engine room for charger and it has no power going to it with breaker for charger switched off, turn on and has power there .. but i get what your saying ..maybe still running some how in background. maybe to store settings or something.. its annoying but i will fit a new d - pole switch on the front of main rcd board so i can turn off charger completely .. then it will be fine it seems :sleeping:

 

[jrudge]

I have an inverter on my boat (previous owner had the 240v TV hard wired into it). That runs fine irrespective of whether the battery charger is on or off.

I have inverters running 24/7 as well for tv ... but they just power the tv not the whole 240v system.

 

[petem]

I have inverters running 24/7 as well for tv ... but they just power the tv not the whole 240v system.

Ah ok, I understand now.

 

[jrudge]

Its a Pure sine Wave Inverter . ive put my mutimeter on live wire on junction box in engine room for charger and it has no power going to it with breaker for charger switched off, turn on and has power there .. but i get what your saying ..maybe still running some how in background. maybe to store settings or something.. its annoying but i will fit a new d - pole switch on the front of main rcd board so i can turn off charger completely .. then it will be fine it seems :sleeping:

My guess given disconnecting live does not stop the buzzing - only neutral - would be that if you put a meter between the neutral wire and earth and or dc system negative you will find a voltage.

It takes 2 wires to create a current and if live is disconnected that only leaves earth and neutral.

As such there maybe some earth issue. I know generator Neutrral is bonded to earth but shore neutral as far as I know is not.

Earth under your inverter is not bonded but floating and apparently ( my hunch ) creating a voltage between earth and neutral.

Who installed the inverter.

Could live and neutral have been transposed ?

 

[petem]

I do worry about this whole plan. Surely someone will accidentally leave the immersion or charger on. At best you'll wreck your batteries. At worst, I don't know. I'd have an inverter powering one or two dedicated sockets with strict instructions what can be plugged into them. Perhaps I'm being over cautious?

 

[jrudge]

I do worry about this whole plan. Surely someone will accidentally leave the immersion or charger on. At best you'll wreck your batteries. At worst, I don't know. I'd have an inverter powering one or two dedicated sockets with strict instructions what can be plugged into them. Perhaps I'm being over cautious?

Agree but easier said than done as all the circuits link. Not impossible at all but you need to isolate bits of the boat when the inverter is running which in practice will mean some double pole relays in several circuits. Usually this is just a user function but in this case that does not work as the charger requires disconnection from neutral and the panel only switches live.

 

[LUNA]

My guess given disconnecting live does not stop the buzzing - only neutral - would be that if you put a meter between the neutral wire and earth and or dc system negative you will find a voltage.

It takes 2 wires to create a current and if live is disconnected that only leaves earth and neutral.

As such there maybe some earth issue. I know generator Neutrral is bonded to earth but shore neutral as far as I know is not.

Earth under your inverter is not bonded but floating and apparently ( my hunch ) creating a voltage between earth and neutral.

Who installed the inverter.

Could live and neutral have been transposed ?

yeah will have another look if get time tommorrow .. i installed . everything definitely wired correctly .. installed on my last 2 boats too.. like i say everything else works fine .. on boat main rcd panel has light .. polarity correct when lit etc .. also inverter has good protection.. Input low voltage protection, overload protection, over temperature protection & Reverse polarity..

 

[jimmy_the_builder]

Agree but easier said than done as all the circuits link. Not impossible at all but you need to isolate bits of the boat when the inverter is running which in practice will mean some double pole relays in several circuits. Usually this is just a user function but in this case that does not work as the charger requires disconnection from neutral and the panel only switches live.

J, could you pls explain a bit more about the issue with the charger still somehow being powered even when switched off at the breaker? Short of going into the engine compartment and physically switching the charger off on the device itself, I have no other way of remotely switching the charger off. I'm not following your 'electronic switch' point.

 

[jimmy_the_builder]

yeah will have another look if get time tommorrow .. i installed . everything definitely wired correctly .. installed on my last 2 boats too.. like i say everything else works fine .. on boat main rcd panel has light .. polarity correct when lit etc .. also inverter has good protection.. Input low voltage protection, overload protection, over temperature protection & Reverse polarity..

Have you just wired the inverter output directly to the 240v bus behind the panel?

Edit: PS did you get a chance to put a clamp meter on the charger output yet? (ie when it is apparently switched off but buzzing)

 

[jrudge]

J, could you pls explain a bit more about the issue with the charger still somehow being powered even when switched off at the breaker? Short of going into the engine compartment and physically switching the charger off on the device itself, I have no other way of remotely switching the charger off. I'm not following your 'electronic switch' point.

I didn’t appreciate when I wrote that the thing still buzzed when live disconnected ( I thought it was off by some other means).

Given it buzzes when only neutral there must be a voltage between neutral and earth / o V dc.

 

[LUNA]

Have you just wired the inverter output directly to the 240v bus behind the panel?

Edit: PS did you get a chance to put a clamp meter on the charger output yet? (ie when it is apparently switched off but buzzing)

no i wired it so you have to physically unplug one and plug in another for safety .. dont want to turn on inverter when shore power left on..

not yet jimmy , will do that tmoz .. im pretty sure will be nothing tho

 

[jrudge]

no i wired it so you have to physically unplug one and plug in another for safety .. dont want to turn on inverter when shore power left on..

not yet jimmy , will do that tmoz .. im pretty sure will be nothing tho

A dual pole change over switch would be better ; with more Poles re the charger )

 

[LUNA]

Thought id try track down the charger manual. managed to find it online . it says about a bipolar switch .. which i guess is double pole. have look at this, taken from manual.

pic

 

[jimmy_the_builder]

Thought id try track down the charger manual. managed to find it online . it says about a bipolar switch .. which i guess is double pole. have look at this, taken from manual.

pic

View attachment 70587

Interesting. Does seem to support jrudge's point. Sounds like you need to rewire the charger supply so that the panel breaker operates a two-pole contactor which then connects the charger to 240v live and neutral. Jrudge's suggestion about a crossover contactor for the inverter output also sounds v sensible.

 

[LUNA]

Interesting. Does seem to support jrudge's point. Sounds like you need to rewire the charger supply so that the panel breaker operates a two-pole contactor which then connects the charger to 240v live and neutral. Jrudge's suggestion about a crossover contactor for the inverter output also sounds v sensible.

yeah i think we getting somewhere now .. makes sense now

 

[LUNA]

A dual pole change over switch would be better ; with more Poles re the charger )

yeah .. ive basically done .. got main shore power at top .. bottom plug is Inverter plug ( plugged in to dummy socket to hold it neat/no pins )

unplug shore power . plug in inverter power . turn on , go cruising

 

[jimmy_the_builder]

yeah .. ive basically done .. got main shore power at top .. bottom plug is Inverter plug ( plugged in to dummy socket to hold it neat/no pins )

unplug shore power . plug in inverter power . turn on , go cruising

View attachment 70588

Gotcha. You may already know this, but that shorepower inlet isn't OE either - the original would have been a Marinco 30A inlet; what you've got there looks like a Commando 16A inlet. If it is then your inlet breaker is rated higher than the inlet fitting itself...

 

[jrudge]

This is honestly not how it should be done.

It should feed into the panel by a double pole switch ( just like a generator ) that changes over from one to the other.

The inverter socket I assume is permanently live unless you fish around in the engine room and turn it off ?

 

[LUNA]

Gotcha. You may already know this, but that shorepower inlet isn't OE either - the original would have been a Marinco 30A inlet; what you've got there looks like a Commando 16A inlet. If it is then your inlet breaker is rated higher than the inlet fitting itself...

Yeah i know .. the marinco was in bad condition .. connecter terminals .. needed changing

 

[jimmy_the_builder]

This is honestly not how it should be done.

It should feed into the panel by a double pole switch ( just like a generator ) that changes over from one to the other.

The inverter socket I assume is permanently live unless you fish around in the engine room and turn it off ?

You're right, it is quite close to the infamous LBOK...

Edit: actually, I take this back - the inverter flying outlet is female, so it's not so bad. I do think the underrated shorepower inlet is a mistake though.