Electrically challenged plus naked enthusiasm

[Malabarista]

Thanks guys trying to get a hang of the laptop first and the the diagram ?

 

[PaulRainbow]

I did say it isn't the easiest diagram to follow!

You were too kind

 

[pvb]

You were too kind

I'm overflowing with Christmas goodwill!

 

[Malabarista]

I guess I’m going to try and rely on some more goodwill. Here it goes again and my thanks are endless. ( a bit like my drawings ) alternator pos is connected via engine wiring

 

[Malabarista]

Got to say Dave that it sounds to me like you are tackling a job outside your skill set and capabilities, and would be better paying for a leccy. I have seen a boat that got a dead short at sea with matching fire and it wasnt funny.

Thanks Birdseye
i have been learning a lot and will continue to do so hopefully no fires

 

[Malabarista]

Just been reading on a marine how to site that i should put the alternator live feed in the house battery side to help the cyrix ( vsr) is this better than on the engine battery side?

 

[Malabarista]

Duplicate post

 

[lw395]

Just been reading on a marine how to site that i should put the alternator live feed in the house battery side to help the cyrix ( vsr) is this better than on the engine battery side?

It depends on where things are physically whether there's any real gain.
If the house batteries are a long way from the engine, then it's a lot of wire.
If it can be done with little extra wire and few connections, it does help, as the house battery should be taking much more charge than the engine battery. At say 60A, even a few milliohms make a difference.

OTOH, for relability, simplicity and ease of future people knowing what's what, keeping the engine/alt/starter/battery 'module' self contained and easy to understand has its merits.
Imagine if damage happens, it's good to be able to run a minimal system with everything else isolated.

I think you need a better diagram. Consider that one day you might want to explain it to a stranger over the phone.
Frankly it's hard to follow on my PC, it looks like too many connections, junctions, pointless breakers and unclear functionality.

 

[PaulRainbow]

Just been reading on a marine how to site that i should put the alternator live feed in the house battery side to help the cyrix ( vsr) is this better than on the engine battery side?

No.

Your alternator is still not connected to the starter positive. That should go from the alternator output to the positive terminal at the starter motor, not the battery and it does not need to be fused.

 

[PaulRainbow]

These diagrams are worse than hard work, ditch the daft idea of using all of the images and stick to simple schematics.

Shore power ; The GI is wrong, you've bi-passed it and connected directly to the 12v negative busbar ! Incoming Earth goes to the GI, GI out goes to the consumer unit. All other connections are made either at the consumer unit, or at a busbar connected to the consumer unit. I'd caution against the busbar as it creates a common point of failure. You also make your connection to the 12v Negative at the the consumer unit, bearing in mind that the boats anode must also be connected to the 12v negative. For the pedants, this specifically applies to Daves plastic boat, other hull types my be connected differently. The shore power fuse goes at the battery end of the cable and only needs to be a simple fuse, no need for a thermal breaker.

The shore charger shown in the diagram is a Sterling Pro Charge Ultra 40a, unless you have already purchased it, look into a Victron charger. A 40a charger is under spec for your battery installation, you should be fitting around 60a/70a, the Victron Skylla 60a should fit the bill.

As already said, alternator output goes to the starter motor positive, no fuse.

Fit the Cyrix next to the isolator switches and connect to the battery terminals of the switches. If there is no danger os the wiring shorting, due to the close proximity to the switches, you only need to fuse one connection. Again, no need for thermal breakers, a 120a fuse if fine.

No idea what's going on with the solar power, looks like a fuse between the panels and the controllers ? Each pair of panels should be wired in series, then both pairs connected in parallel to a single controller, no fuses between the panels and controller. The controller should ten be wired to the domestic battery circuit, with the controller fitted as close to the batteries as possible and fused at the end of the cable farthest from the controller, fuse again, not breaker.

You have fused the domestic supply cable at the batteries, which is fine, again no need for thermal breakers. But, you need to separately fuse every cable that connects to that unswitched bus, with a fuse rated for the current capacity of the cable.

 

[Malabarista]

Hi Paul
At the risk of becoming repetitive i would like to say again thanks for helping me out with this.
I had put the fuses inline between the solar panels following a schematic from outback. After further research and your remarks i am glad I didn’t buy them. ?
I was mightily confused with the GI so thanks for clearing that up. To be completely clear the negative 12vdc bus connects to the engine chassis,the consumer unit earth bar ( inside the 240v plastic box) and the anode yes?
The alternator and starter are already wired together from what it look like ( please see photos).
From the unswitched pos busbar the two bilge pumps are fused separately ( 15 & 5 amp) at the battery end and again at their respective switch panels. Less than two metres of the 2.5mm cable you recommended when we met.
I already bought the sterling charger unfortunately and it has been working for 2 years ( on a much smaller bank). I have taken your advice and ditched one pair of the trojans although i am tempted to use them as an engine starter battery. This is nothing to do with CCA versus AH but more to do with woodworking. I built a rather lovely battery bay to house the full eight ?.
I also bought two Victron MPPT 100/30 controllers in the interests of redundancy and shading with each having a max input of 440W. Does this mean I cannot use both. My 350W big panel on the hardtop also came with a controller ( PWM) which i may take as a spare in case i blow something up!
So my plan was to join the 2 150W panels on the Port pushpit rail in series to one controller and Stbd pushpit rails to the other to minimise the effects of shading from the mizzen boom. Am i being daft again?

 

[Malabarista]

There is an echo on my boat. Everything posts twice!

 

[Malabarista]

It depends on where things are physically whether there's any real gain.
If the house batteries are a long way from the engine, then it's a lot of wire.
If it can be done with little extra wire and few connections, it does help, as the house battery should be taking much more charge than the engine battery. At say 60A, even a few milliohms make a difference.

OTOH, for relability, simplicity and ease of future people knowing what's what, keeping the engine/alt/starter/battery 'module' self contained and easy to understand has its merits.
Imagine if damage happens, it's good to be able to run a minimal system with everything else isolated.

I think you need a better diagram. Consider that one day you might want to explain it to a stranger over the phone.
Frankly it's hard to follow on my PC, it looks like too many connections, junctions, pointless breakers and unclear functionality.

Thanks for helping me out with this. I am working on a new draft ?

 

[PaulRainbow]

To be completely clear the negative 12vdc bus connects to the engine chassis,the consumer unit earth bar ( inside the 240v plastic box) and the anode yes?

Yes, all need to be connected.

The alternator and starter are already wired together from what it look like ( please see photos).

Yes, pretty standard stuff, leave it alone

From the unswitched pos busbar the two bilge pumps are fused separately ( 15 & 5 amp) at the battery end and again at their respective switch panels. Less than two metres of the 2.5mm cable you recommended when we met.

Big fuse at battery to protect 35mm cable to busbar is fine, individual pump fuses also fine, but you will have stepped down in cable size from the busbar to the fuse panel, this cable is now unprotected.

I already bought the sterling charger unfortunately and it has been working for 2 years ( on a much smaller bank).

OK, the sterling charger is fine, Victron is better, but no point changing for the sake of it. But, 40a for the proposed battery bank is under spec. However, you have a big solar array so might get away with it. If you get a few cloudy days and you cane the batteries they might suffer, suck it and see.

I have taken your advice and ditched one pair of the trojans although i am tempted to use them as an engine starter battery. This is nothing to do with CCA versus AH but more to do with woodworking. I built a rather lovely battery bay to house the full eight ?.

Be a bit daft IMO. Sell them and buy a £100 AGM starter battery.

I also bought two Victron MPPT 100/30 controllers in the interests of redundancy and shading with each having a max input of 440W. Does this mean I cannot use both. My 350W big panel on the hardtop also came with a controller ( PWM) which i may take as a spare in case i blow something up!
So my plan was to join the 2 150W panels on the Port pushpit rail in series to one controller and Stbd pushpit rails to the other to minimise the effects of shading from the mizzen boom. Am i being daft again?

Ref shading, you are correct to keep them in pairs as you have, as one panel in a series array will badly affect the whole array. In your case, if the port panels are in shade, the Stb pair won't be affected by that. However, those shading affects occur at the panels, the controllers don't get affected. So, if you had both pairs connected to the same controller and one pair was shaded (or even covered up completely) it won't make any difference to the other pair or the controller. Fitting a single controller removes the risk of one controller affecting the other.

 

[Malabarista]

After the Christmas shenanigans and much research I think I am ready (once again) to expose myself as an electrical numpty. I know I am asking a lot but if anyone cares to have look and comment on my efforts I would be extremely grateful. Thanks

 

[Malabarista]

Big fuse at battery to protect 35mm cable to busbar is fine, individual pump fuses also fine, but you will have stepped down in cable size from the busbar to the fuse panel, this cable is now unprotected.

Hi Paul
I hope Santa brought you everything you desired. The cable to the fuse box indeed steps down to 10mm2 which is big for its intended max 20A draw ( both pumps running) however as it is only 300mm long and not ‘bundled’ I am hoping that it will do the job. Please tell me if you think it is unsuitable although as a 35mm2 cable won’t fit into the fuse holder I am not sure what i could about it.

 

[PaulRainbow]

No problem with the cable size, for those loads. But, it is unfused. The main battery fuse would be unlikely to blow if that cable or the internal gubbins of the fuse box shorted out. As it's only 300mm long, provided it can absolutely 100% be impossible to short the cable, you could possibly argue that a fuse isn't needed.

 

[Malabarista]

No problem with the cable size, for those loads. But, it is unfused. The main battery fuse would be unlikely to blow if that cable or the internal gubbins of the fuse box shorted out. As it's only 300mm long, provided it can absolutely 100% be impossible to short the cable, you could possibly argue that a fuse isn't needed.

Thanks Paul

 

[Malabarista]

My hat is off to those of you who do this for a living. The physical work is bad enough wrestling 70mm cables through the boat and putting junction boxes in spine twisting locations. It’s the switchboard that is giving me nightmares. Starting to look scary

 

[BabaYaga]

After the Christmas shenanigans and much research I think I am ready (once again) to expose myself as an electrical numpty. I know I am asking a lot but if anyone cares to have look and comment on my efforts I would be extremely grateful. Thanks

A bit late to this perhaps, but I think that the 3 way switch in your AC circuit diagram should be double pole, that is switch both line and neutral.