Generator, inverter, solar panels, 24V bank

[Pastis]

Hello everybody,

 

we are the lucky new owners of a narrowboat, but we have some difficulties understanding the electrical system in place.

As far as we can see, the 4x6V leisure batteries for the 24V system are linked to an inverter, and a switch let us choose for the 230V if we want it coming from shoreline (but we don't have access to shoreline), fitted generator or inverter. It seems that only the alternator is charging the batteries, as an amper/volt meter shows no input current when the generator is running. Eventually the shoreline was also going to the inverter which has a charge mode (+inverter mode), so first question is : could we wire the generator to the AC input of the inverter to replace the shoreline charge system ?
For the second part, we want to install solar panels, 2x100w, in series with an MPPT controller. Being very new to narrow boating, we looked at a lot of forums and videos but the question of wiring is never addressed once passed the roof. What is the best practice, going above the ceiling ? Should we remove part of the fitting, or make the cables going along the walls ? Shall we wire the MPPT in parallel of the inverter, directly to the battery bank?

 

Many thanks any advices, cheers.

 

PS. If anyone knows an electrical engineer used to narrowboats who works in Oxfordshire, we would be glad to have the contact for an expertise / installation

[Alan de Enfield]

I'm a bit confused you say :

 

16 minutes ago, Pastis said:

if we want it coming from shoreline (but we don't have access to shoreline), fitted generator or inverter.

but then talk about connecting the generator :

 

 

16 minutes ago, Pastis said:

o first question is : could we wire the generator to the AC input of the inverter to replace the shoreline charge system ?

If you do have a generator then is its output 230v ?

If so you cannot connect it to the Inverter as the input for the inverter is 12v.

 

Are you mistaking the "inverter input" for the battery charger input ?

[Tony Brooks]

1 hour ago, Pastis said:

Hello everybody,

 

we are the lucky new owners of a narrowboat, but we have some difficulties understanding the electrical system in place.

As far as we can see, the 4x6V leisure batteries for the 24V system are linked to an inverter, and a switch let us choose for the 230V if we want it coming from shoreline (but we don't have access to shoreline), fitted generator or inverter. It seems that only the alternator is charging the batteries, as an amper/volt meter shows no input current when the generator is running. Eventually the shoreline was also going to the inverter which has a charge mode (+inverter mode), so first question is : could we wire the generator to the AC input of the inverter to replace the shoreline charge system ?
For the second part, we want to install solar panels, 2x100w, in series with an MPPT controller. Being very new to narrow boating, we looked at a lot of forums and videos but the question of wiring is never addressed once passed the roof. What is the best practice, going above the ceiling ? Should we remove part of the fitting, or make the cables going along the walls ? Shall we wire the MPPT in parallel of the inverter, directly to the battery bank?

 

Many thanks any advices, cheers.

 

PS. If anyone knows an electrical engineer used to narrowboats who works in Oxfordshire, we would be glad to have the contact for an expertise / installation

Discussed in the electrical notes on my website. "Best" is not a very good word, "practical" may be better. So what is practical on one boat may not be on another.

 

Possible wiring routes:

 

Along the underside of the gunwales as long as the required separation between fuel, gas and 240V AC is observed.

Along the angle formed between the cabin ceiling and wall, usually hidden by some for of enclosed "pelmet".

Along the centre of the roof above a removable decorative panel/channel.

 

Wiring may also be run behind the cabin lining and passed through holes drilled in the strengthening braces but you  won't be able to get to these without a of of work. It may also be run in trunking above the ceiling but unless provision is made to unscrew parts of the ceiling you will have difficulty accessing it.

 

Tb-Training.co.uk

 

I would expect the generator to power a battery charger so the batteries are charged with the generator running but who knows, each boat is a one off. The inverter MIGHT be a combi-unit that has a battery charger built in and if so that feature is probably not turned on.

 

2 Solar panels can be wired in series or parallel with  MPPT controller. there are advantages and disadvantages to each method and it has been discussed in various topics on the forum multiple times in the past.

 

The wiring of the controller depends on it the inverter is a combi-unit or not. If its not then the solar needs connecting direct to battery negative and the positive to the battery side of the master switch with a fuse close to that connection. If it is a combi-unit then you can probably utilise the combi-unit wiring so the controller will be in parallel to the inverter.

 

 

PS I fitted my solar wiring plus TV aerial lead, speaker leads and the odd other wire behind an L shaped timber trim fitted below the cabin side to roof joint. 

Edited October 4, 2020 by Tony Brooks

[WotEver]

1 hour ago, Pastis said:

Eventually the shoreline was also going to the inverter which has a charge mode (+inverter mode), so first question is : could we wire the generator to the AC input of the inverter to replace the shoreline charge system ?

Yes.

1 hour ago, Alan de Enfield said:

Are you mistaking the "inverter input" for the battery charger input ?

I think you missed...

1 hour ago, Pastis said:

Eventually the shoreline was also going to the inverter which has a charge mode (+inverter mode)

 

So it's a Combi.

[Tony Brooks]

3 minutes ago, WotEver said:

Yes.

I think you missed...

 

So it's a Combi.

 

I missed that. Then there is a good chance the charge function is turned off.

[Alan de Enfield]

20 minutes ago, WotEver said:

I think you missed...

2 hours ago, Pastis said:

Eventually the shoreline was also going to the inverter which has a charge mode (+inverter mode)

 

So it's a Combi.

 

No I didn't, but the OP said that he was looking to connect 230v from a generator to the INPUT OF THE INVERTER.

I was simply pointing out that the input to the inverter was 12v,DC not, 230v AC

As we know there will be two inputs going into the  combi 'box', one for the charger and one for the inverter, the OP needs to ensure he connects the correct ones to the correct source.

[Pastis]

@Alan de Enfield, @Tony Brooks, @WotEver,

 

thank you very much for your quick answers, Tony your website seems full of ressources, a shame not to have found it before !

Ok so for the solar panels, I think we will go for the corner solution  If I well understood, as our battery bank is 24V and we have the MPPT, connecting the panels in series is quite the best thing to do. To fix the installation, we've read good feedbacks about magnets, and to go through the roof, we were hesitating between using the pigeon box (but may be difficult to waterproof) or drilling (but that we would have preferred to avoid).

 

Talking about the generator charging the batteries, here is the schematics of the inverter (yes this is a combi, sorry for the misunderstanding). For now, I think the shoreline is connected to "AC input", nothing is on AC output 'power' (AC output "short break" is meant to reduce battery power consumption is no loads, I think but not sure). Now when selecting the charge mode, the inverter don't see anything (the AC input light is off, all lights are off...), so I suppose only the shoreline is wired to the AC input. So I could eventually plug here the generator, that's nice to hear ! But so much wires around the generator :S

 

 

And so for the position of the MPPT, in parallel of the inverter (using the same battery fuse 4)? If the battery bank is 24V, I read somewhere that a there should be somewhere a charge controller, wired to both the alternator and the inverter "battery terminals" ?

 

Thank you again for your advices !
 

Edited October 4, 2020 by Pastis

[Alan de Enfield]

22 minutes ago, Pastis said:

@Alan de Enfield, @Tony Brooks, @WotEver,

 

thank you very much for your quick answers, Tony your website seems full of ressources, a shame not to have found it before !

Ok so for the solar panels, I think we will go for the corner solution  If I well understood, as our battery bank is 24V and we have the MPPT, connecting the panels in series is quite the best thing to do. To fix the installation, we've read good feedbacks about magnets, and to go through the roof, we were hesitating between using the pigeon box (but may be difficult to waterproof) or drilling (but that we would have preferred to avoid).

 

Talking about the generator charging the batteries, here is the schematics of the inverter (yes this is a combi, sorry for the misunderstanding). For now, I think the shoreline is connected to "AC input", nothing is on AC output 'power' (AC output "short break" is meant to reduce battery power consumption is no loads, I think but not sure). Now when selecting the charge mode, the inverter don't see anything (the AC input light is off, all lights are off...), so I suppose only the shoreline is wired to the AC input. So I could eventually plug here the generator, that's nice to hear ! But so much wires around the generator :S

 

 

And so for the position of the MPPT, in parallel of the inverter (using the same battery fuse 4)? If the battery bank is 24V, I read somewhere that a there should be somewhere a charge controller, wired to both the alternator and the inverter "battery terminals" ?

 

Thank you again for your advices !
 

If you are not having a permanently wired, 'built in' generator, then yes, you simply plug the 'land line' directly from your generator into the same 'plug' on the boat that you would plug the land line from the bollard into 

[WotEver]

24 minutes ago, Pastis said:

And so for the position of the MPPT, in parallel of the inverter (using the same battery fuse 4)?

The fuse is to protect the wiring and it is a dead cert that the inverter's fuse will be way too big to protect the cable coming from the MPPT, so that will require its own fuse. You can connect the MPPT cables directly to the batteries (via that fuse, but keep it outside of the battery box), or to the battery side of the isolation switch, or if it's more convenient, to the DC connections on the Combi.  Electrically they're all the same, and any of them will comply with the BSS.

30 minutes ago, Pastis said:

I read somewhere that a there should be somewhere a charge controller, wired to both the alternator and the inverter "battery terminals" ?

Certainly not a 'requirement', and they make the alternator work a lot harder than it's probably designed to do. Nevertheless it's an option.  What alternator do you have?

[Tony Brooks]

To amplify @WotEver's post. If you use the inverter's DC input cables to send solar to the batteries the fuse he speaks of must be as close as practical to the point the MPPT cable joins the inverter positive, Its there to protect the cable to the MPPT in case it shorts.

 

He also tells you the other places you ca make the MPPT connection but be aware that solar and any other charger is allowed to be connected to the battery side of the master switch so it can still charge when you leave the boat for a period when many boaters turn the master switch off. This is why you can use the combi-unit wires to connect solar to the battery but not an inverter that should be fed via a master switch.

 

Some boaters are now fitting house type solar panels that have a voltage of around 30 volts. Others use so called 12V panels that have something like a 20 volt output. If you have 12V panels then as you say they will have to go in series for a 24 volt system but 30 volt panels may well work in parallel if that seem a better choice.

Edited October 5, 2020 by Tony Brooks

[Bod]

17 hours ago, Pastis said:

Hello everybody,

 

we are the lucky new owners of a narrowboat, but we have some difficulties understanding the electrical system in place.

As far as we can see, the 4x6V leisure batteries for the 24V system are linked to an inverter, and a switch let us choose for the 230V if we want it coming from shoreline (but we don't have access to shoreline), fitted generator or inverter. It seems that only the alternator is charging the batteries, as an amper/volt meter shows no input current when the generator is running. Eventually the shoreline was also going to the inverter which has a charge mode (+inverter mode), so first question is : could we wire the generator to the AC input of the inverter to replace the shoreline charge system ?
For the second part, we want to install solar panels, 2x100w, in series with an MPPT controller. Being very new to narrow boating, we looked at a lot of forums and videos but the question of wiring is never addressed once passed the roof. What is the best practice, going above the ceiling ? Should we remove part of the fitting, or make the cables going along the walls ? Shall we wire the MPPT in parallel of the inverter, directly to the battery bank?

 

Many thanks any advices, cheers.

 

PS. If anyone knows an electrical engineer used to narrowboats who works in Oxfordshire, we would be glad to have the contact for an expertise / installation

Some clear photos of what you have, will make this topic much clearer.

For instance, we have 4x6v batteries, but are set up to provide 12v.

Once it is clear exactly what equipment you have, then correct advice can be given.

 

Bod

Edited October 5, 2020 by Bod
spelling

[Pastis]

Ok, brillant,

 

So just between the isolation switch and the batteries, this part is fortunatly accessible. Still I don't get how the wiring has been done : As I have a three stages switch to choose 230V coming from Shore / Gen / Combi (AC output), the three devices are behind an interrupter to the cabin circuit. Then there is two sockets below the inverter, the AC input of the combiner's is plugged in one, the other one might be to plug the shoreline, would you think both are only connected one to each other? Should I link the generator to these switch ? What if shoreline + generator present at the same time in this situation? Wouldn't it be better to put the combi AC input after the switch for the main circuit ? it would benefit from both possible sources, or is it a problem that the AC input is somehow linked to the AC output of the combi in inverter mode ?

For the panels installation, I suppose I will need that kind of entry gland  (@Tony Brooks, separation with 230 AC, how much, is there a reason ? I don't know where run the cables). Do you have an advice on how to fix it (I read about sikaflex but it seems messy).

 

Many thanks !

 

 

[WotEver]

11 minutes ago, Pastis said:

would you think both are only connected one to each other?

Who knows?  I think you need to employ the services of someone who understands boat electrics to at the very least advise, and possibly to do a little rewiring if required.

[Alan de Enfield]

 

Whereabouts in the world are you - it sounds to me as if a visit from a forumite with some electrical knowledge would be beneficial.

 

 

19 minutes ago, Pastis said:

What if shoreline + generator present at the same time in this situation? 

 

That is very dangerous, you potentially have 440volts in your 220v circuit. Any 220v equipment connected at that time would be 'fried' and release the magic smoke'

If there is even a possibility that you can have two sources of AC supply connected at the same time your wiring system is faulty and should be re-done.

 

It is also a Boat safety Check.

 

Edit to add BSS requirements

 

3.9.1 Is it impossible to connect simultaneously more than one power source to the alternating current distribution system?

Check for the presence of one or more shore‐power inlet connections.

Check for the presence of additional power sources(e.g. generators and inverters).

Check for the presence of one or more means of selection between all the identified power sources.

Check that the selection facilities prevent more than one power source being connected to the alternating current distribution system at any one time, and that they prevent the male pins on shore‐power inlet connections being ‘live’ when an alternative power source is selected.

Only one power source may be connected to the alternating current distribution system at any one time. The male pins on shore‐power inlet connections must not be ‘live’ when an alternative power source is connected to the alternating current distribution system.

Edited October 5, 2020 by Alan de Enfield

[Tony Brooks]

27 minutes ago, Pastis said:

Ok, brillant,

 

So just between the isolation switch and the batteries, this part is fortunatly accessible. Still I don't get how the wiring has been done : As I have a three stages switch to choose 230V coming from Shore / Gen / Combi (AC output), the three devices are behind an interrupter to the cabin circuit. Then there is two sockets below the inverter, the AC input of the combiner's is plugged in one, the other one might be to plug the shoreline, would you think both are only connected one to each other? Should I link the generator to these switch ? What if shoreline + generator present at the same time in this situation? Wouldn't it be better to put the combi AC input after the switch for the main circuit ? it would benefit from both possible sources, or is it a problem that the AC input is somehow linked to the AC output of the combi in inverter mode ?

For the panels installation, I suppose I will need that kind of entry gland  (@Tony Brooks, separation with 230 AC, how much, is there a reason ? I don't know where run the cables). Do you have an advice on how to fix it (I read about sikaflex but it seems messy).

 

 

Many thanks !

 

 

 

I don't understand why a combi has a three way switch because if its a reputable make it will synchronise itself to the shore line frequency and if you try to draw more current that the shoreline can supply the inverter supplements it so the shoreline input would go straight to the relevant connections on the inverter. The inverter output would then go to the boat's AC consumer unit ( RCB and mcb/RCBO) and onto the boats 240V wiring to wall plugs etc.  The inverter could not care less if that mains input comes from a shoreline or a generator so you would just plug the generator into the shoreline socket. I don't see why in your case a switch is required.

 

This sounds like a DIY/bodged install by someone who did not fully understand the equipment so I agree that you maybe best to consult a professional so you et the optimum install.  As long as the mains consumer unit is in the correct place in the circuit I think its safe a sit is but you forgo features that may be useful if your demand exceeds the generator or shoreline maximum.

 

Please note that I am a low voltage DC person so am less than happy to give advice about AC on boats.

 

The separation  distance is in the notes I pointed you to and I think in  the BSS hand book. I think the distance is 50mm or less if one of the services is run in a conduit. Some hold the outer sheath on the mains wiring counts as the conduit but with some of the odd BSS inspector pronouncements we hear about I would not risk it.

 

Unless you want water leaks some form of gland in the roof is required. If using the one you show I would position it under a panel so the  sun can not degrade the plastic or look in salty water outlets for a metal one. Some people route the solar cables through an existing roof vent but I think that is a bit of a bodge.

[WotEver]

4 minutes ago, Tony Brooks said:

I don't understand why a combi has a three way switch... <snip> This sounds like a DIY/bodged install by someone who did not fully understand the equipment...

Agreed. Hence my suggestion that OP seeks first hand advice. 

[Alan de Enfield]

16 minutes ago, Tony Brooks said:

I don't understand why a combi has a three way switch

This, and other comments by the OP is why I suggested he contact a person with an understanding of Boat Electrics.

[Tony Brooks]

1 hour ago, Alan de Enfield said:

This, and other comments by the OP is why I suggested he contact a person with an understanding of Boat Electrics.

I just thought it best to add my voice to your's and Tony's because I agree.

[cuthound]

22 hours ago, Pastis said:

 

 

PS. If anyone knows an electrical engineer used to narrowboats who works in Oxfordshire, we would be glad to have the contact for an expertise / installation

 

Clive Mant.

 

http://www.mantmarine.co.uk/page1.html

[Tacet]

On 04/10/2020 at 16:41, Pastis said:

 

As far as we can see, the 4x6V leisure batteries for the 24V system are linked to an inverter

 

On 04/10/2020 at 18:47, Alan de Enfield said:

 

No I didn't, but the OP said that he was looking to connect 230v from a generator to the INPUT OF THE INVERTER.

I was simply pointing out that the input to the inverter was 12v,DC not, 230v AC

 

More likely to be 24v than 12v, surely

[Alan de Enfield]

1 minute ago, Tacet said:

More likely to be 24v than 12v, surely

 

I would question if the OP has the knowledge to determine how the 4 x 6v batteries are wired (and assumes 4 x 6 = 24) The vast majority of NB's are 12v, but it is easily answered by looking at the Alternator output voltage rating, or the Inverter input specification.

[TheBiscuits]

1 hour ago, Alan de Enfield said:

 

I would question if the OP has the knowledge to determine how the 4 x 6v batteries are wired (and assumes 4 x 6 = 24) The vast majority of NB's are 12v, but it is easily answered by looking at the Alternator output voltage rating, or the Inverter input specification.

 

Yes, I agree.  A photo showing the cabling between the batteries would let us tell them clearly though.

[Alan de Enfield]

9 hours ago, TheBiscuits said:

 

Yes, I agree.  A photo showing the cabling between the batteries would let us tell them clearly though.

 

True - I was thinking the OP could look at the equipment and 'read the label', but you are correct, we could see from a photo of the 6 batteries showing their interconnects.

[Bod]

see #11

 

Bod