My battery isolation / BSC

[LadyG]

OK, 

I [as in an electrician] has simplifed wiring essentially thrown out two huge Chinese inveters, now have a Victron 375 Victron Phoenix 375W, 12V Inverter With VE.Direct.

To explain in my terms, the leisure bank at stern and the leisure at bow  each have an isolator at the stern.they are one leisure bank but have independant isolators [elephant ears]

BSC says {according to examiner], that the "run" is too long [14m] , so should [advisory] have an isolator at front. The invertor is at the front. The front batteries [2=1] is fused' 

I have put a "battery isolator" label  on front step, "as requested"

Edited March 21, 2020 by LadyG

[cuthound]

Make sure that no socket outlets fed from the two different inverters are within 2 metres (an armstretch) of each other.

 

As they are not synchronised together you can get 400 volts between them.

[LadyG]

39 minutes ago, cuthound said:

Make sure that no socket outlets fed from the two different inverters are within 2 metres (an armstretch) of each other.

 

As they are not synchronised together you can get 400 volts between them.

I got rid of the two invertors feeding Mains ring, and or washing machine.and put one Victron which outputs to one socket. That is it.

Preiously two 13 mp sckets from invertrs were 6 ft apart.

 

I insisted on this, as Mr Bodger Owner / Electrician was an idiot [edited swearword]

 

Edited March 21, 2020 by LadyG

[LadyG]

42 minutes ago, cuthound said:

Make sure that no socket outlets fed from the two different inverters are within 2 metres (an armstretch) of each other.

 

As they are not synchronised together you can get 400 volts between them.

Why/how ?

[WotEver]

3 minutes ago, LadyG said:

Why/how ?

Because if one peak of an inverter was at positive 230V when the other inverter was at negative 230V the voltage across them would be 460V.  Also worth noting that the peak voltage of a sinusoidal 230V is (230 x 1.414) 320V. RMS = Root Mean Squared (a kind of average voltage). 

I’m not understanding the arrangement as described in the OP. It makes zero sense to split a domestic bank, particularly so with it split down the length of the boat. BSS man is correct however that a battery isolator should be as close as practical to the battery. 

[LadyG]

1 hour ago, WotEver said:

Because if one peak of an inverter was at positive 230V when the other inverter was at negative 230V the voltage across them would be 460V.  Also worth noting that the peak voltage of a sinusoidal 230V is (230 x 1.414) 320V. RMS = Root Mean Squared (a kind of average voltage). 

I’m not understanding the arrangement as described in the OP. It makes zero sense to split a domestic bank, particularly so with it split down the length of the boat. BSS man is correct however that a battery isolator should be as close as practical to the battery. 

I did not design it that way.

Previous owner decided to use bow thruster batteries [bow thruster now disconnected].

In my mind the domestic isolator is connected to three x 135ah in one "clump", at stern. They have an isolator . Do they need fat cables to this isolator switch?

The former bow thruster batteries [2x ?120ah] are near the bow, there is a feed to invertor, there may be 5amp mains charger fweeding those batteries.

I am on my 5th and final electrician. Budget pretty much maxed out.

IF the solution wast scrap everything at bow, it would have been suggested.

 

 

Edited March 21, 2020 by LadyG

[MtB]

16 minutes ago, LadyG said:

I am on my 5th and final electrician. Budget pretty much maxed out.

 

I thought you had a genius electrician who normally worked on £5m superyachts....

 

Why not ask him? Or are you double-checking because you don't trust what he says?

 

 

[LadyG]

34 minutes ago, Mike the Boilerman said:

 

I thought you had a genius electrician who normally worked on £5m superyachts....

 

Why not ask him? Or are you double-checking because you don't trust what he says?

 

 

He is not here. He is expensive. He is competant., but like most men, I pay £300 per day .... .................................. ...............

 

We discuss, then we agree, a bit like my marriage ... he does what he likes, .? joking .... it is not a perfect system, but it will be safe, robust, predictable, a good working system for a liveaboard using a marina in bad weather.

I ask on here ~cos I need the thoughts of the gurus.

I confess we will not agree on solar, I will have to insist on as much as possible, within budget

It's a matter of compromise £5K to do it from scratch, plus rip out inside'

OR take it to London, sell it, and buy a sailaway. I am 85% near the end of this project, one project is enough at my time of life!

Edited March 21, 2020 by LadyG

[Detling]

Isolator both end for safety, the danger is if there is short to the hull somewhere on that length, the battery can put out hundreds of amps causing the wire to catch fire. If by elephant ears you mean the cheap isolators with a removable paddle switch, change them before they melt. They are overated, my 100 amp one decided to soften and die with about 3 amps lighting and a pump on it, the one someone fitted for my bow thruster became a block of melted black plastic first time it was used for more than 2 seconds.

[Keeping Up]

If there are 2 isolators I would attach a label to each stating the location of the other one, so there is no risk of somebody switching just one off and assuming that the electrics are now safe to work on.

[WotEver]

As there is no functioning bow thruster then ideally the two batteries up front should either be relocated at the back with the others or recycled. 

[blackrose]

21 hours ago, WotEver said:

As there is no functioning bow thruster then ideally the two batteries up front should either be relocated at the back with the others or recycled. 

Agreed. I don't really understand how or why a defunct set of BT batteries became a second domestic bank, but since they no longer need to be at the bow then get rid of them and get rid of the second system and add the batteries to the domestics at the stern if a bigger bank is required (assuming they are of the same battery type). Simplify the whole system so that there's a single domestic battery bank. Overly-complex electrical systems just add unnecessary complications for anyone trying to use or work on them. 

Edited March 23, 2020 by blackrose

[WotEver]

56 minutes ago, blackrose said:

Overly-complex electrical systems just add unnecessary complications for anyone trying to use or work on them. 

And invariably don’t work very well either. 

[Iain_S]

On the other hand, it can be useful to have a battery bank in the bow,

 

On the trip boat I'm involved with, the bow battery bank, originally mainly for the now removed bow thruster, powers the water pump, tunnel lights, navigation lights and horn. It has its own isolator at the bow, and is connected to a split charge diode at the stern. The lights and horn are switched from the stern via relays at the bow. It works and saves volt drop problems on the water pump and horn.

[LadyG]

16 hours ago, Iain_S said:

On the other hand, it can be useful to have a battery bank in the bow,

 

On the trip boat I'm involved with, the bow battery bank, originally mainly for the now removed bow thruster, powers the water pump, tunnel lights, navigation lights and horn. It has its own isolator at the bow, and is connected to a split charge diode at the stern. The lights and horn are switched from the stern via relays at the bow. It works and saves volt drop problems on the water pump and horn.

I think this was "the plan", if there ever was one, which I doubt.

The spagetti junction at the bow has been cleaned up, but now appears to have no isolator, at the moment. The water pump , horn, tunnel and lights and maybe nav lights and a DC "fuse box [I think you might call it] are all in that area. Plus what may be a 5amp charger.

There were two invertors I had them removed as I was never going to run washing machine at stern off a chinese 3Kw invertor, or off mains/engine with such bizarre electrics. A new 375 Victon invertor with an isolator supplies 230v to a UK socket. This is to charge/run laptop and phone and anything else, not sure about kettle.

A new DC cable is to connect {a new fridge] to bow battery, 

Of course better to rip it all out, and re-wire, estimate £5K, and hope cable runs are all in the cable run "boxing" or otherwise accessable.

PS I did buy a split charge diode, not sure where it should go, what use it is, it just seemed like a good idea at the time [july 2019].

Edited March 24, 2020 by LadyG

[Dr Bob]

18 hours ago, Iain_S said:

On the other hand, it can be useful to have a battery bank in the bow,

 

On the trip boat I'm involved with, the bow battery bank, originally mainly for the now removed bow thruster, powers the water pump, tunnel lights, navigation lights and horn. It has its own isolator at the bow, and is connected to a split charge diode at the stern. The lights and horn are switched from the stern via relays at the bow. It works and saves volt drop problems on the water pump and horn.

The answer of course is to fit lithiums and ditch the batteries at the pointy end. The voltage of the lithiums is usually over 13.0V when the engine is not running and no solar so plenty of voltage to run the water pump and other gubbins at the front with these long runs of wire.

Solar works so much better with lithiums.

[Alan de Enfield]

2 hours ago, LadyG said:

There were two invertors I had them removed as I was never going to run washing machine at stern off a chinese 3Kw invertor, or off mains/engine with such bizarre electrics. A new 375 Victon invertor with an isolator supplies 230v to a UK socket. This is to charge/run laptop and phone and anything else, not sure about kettle.

You won't be running a kettle or washing machine of a 375w inverter.

[cuthound]

9 hours ago, Alan de Enfield said:

You won't be running a kettle or washing machine of a 375w inverter.

 

Might just about be able to run one of the mini twin tubs washing machines, depending on inverter overload capability and washing machine inrush current peak and duration.

[LadyG]

20 hours ago, Dr Bob said:

The answer of course is to fit lithiums and ditch the batteries at the pointy end. The voltage of the lithiums is usually over 13.0V when the engine is not running and no solar so plenty of voltage to run the water pump and other gubbins at the front with these long runs of wire.

Solar works so much better with lithiums.

Maybe if I was starting from scratch and had an interest in these things, but I'm not, and I dont.?

Edited March 25, 2020 by LadyG

[LadyG]

10 hours ago, cuthound said:

 

Might just about be able to run one of the mini twin tubs washing machines, depending on inverter overload capability and washing machine inrush current peak and duration.

I'm OK  with using marina laundry, expensive compared to a house, and I need to save up a weeks clothing, but there is not as much as there was when I was sanding and cleaning. If I stay on board long term on a mooring for example, I might get a decent w/machine and an inverter close to both batteries and invertor. it looks like another major project, so I think I'd rather sell this one and get one with a better set up.

In fact not having a washing machine that works like a domestic machine is the biggest drawback to living on board. Oh, and the Webasto waking me up at 03.00 'cos I let the fire go out ?

Edited March 25, 2020 by LadyG

[MtB]

2 hours ago, LadyG said:

I'm OK  with using marina laundry

 

How is that gonna work then, given your other thread announcing you are leaving the marina?

 

 

[Dr Bob]

And our marina shutting its drier down........

[MtB]

2 hours ago, Dr Bob said:

And our marina shutting its drier down........

 

Well good, tumble driers are half the problem where global warming is concerned. All that heat out the exhaust duct!

 

[WotEver]

4 hours ago, Mike the Boilerman said:

 

Well good, tumble driers are half the problem where global warming is concerned. All that heat out the exhaust duct!

 

Interestingly, and I’ve mentioned this on here before, our condensing dryer doesn’t have an exhaust outlet. 

[MtB]

3 minutes ago, WotEver said:

Interestingly, and I’ve mentioned this on here before, our condensing dryer doesn’t have an exhaust outlet. 

 

It probably has a cold water supply and drain connection instead though...