Wiring the motorhome properly.

[68c]

How do you control the risk of legionaires disease if just keeping the water tank luke warm rather than heating to 60°

 

[Gromett]

I've read that solar dumping to hot water is more effective than dumping to a fridge for example. It was said that a fridge doesn't use enough power for it to be a good solar dump destination. No idea how valid that is but, I'll be dumping to hot water tank too and I don't plan on having diesel or gas.

My fridge will be a 240V one run off the batteries. So the batteries will have to be full for the dumping to happen. Water is the best destination for any excess I think.

 

[Gromett]

How do you control the risk of legionaires disease if just keeping the water tank luke warm rather than heating to 60°

It wont' be kept at 60°C When there is too much solar to store in the battery and not enough to keep the water hot, hot, hot. Then each day the timer will click on and fully heat the tank ready for morning ablutions.

But it is a very good thing for people to bear in mind.

 

[autorouter]

How do you control the risk of legionaires disease if just keeping the water tank luke warm rather than heating to 60°

Need to take it to 60°C for an hour or so at least once a week. That's what is done with hot water tanks with a heat pump, they usually have an automatic weekly cycle doing just that

 

[lesc]

Regarding breakers MCB's next time you go abroad, or ask a funster on return from France, pop in Leroy Merlin or Brico Depo, and get some proper breakers, single module double pole. Makes the installation much simpler, and takes half the space in CU. Uk double pole are double module so you loose allot of ways in the CU.
And remove the neutral bar completely, you don't need it.

Like this ones
View attachment 1078162View attachment 1078163

Hi, What consumer unit did you put the MCBs in ?
Im a bit concerned about not using one specifically rated for motorhomes.
Thank you. Les.

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[autorouter]

Im a bit concerned about not using one specifically rated for motorhomes.

12VPlanet do an IP65 rated (weatherproof) consumer unit if you are concerned about water ingress problems:

C-Pak 4-Module Unpopulated IP65 AC Mains Consumer Unit Enclosure

Waterproof 4-module AC consumer unit enclosure for campervans, caravans, motorhomes & boats. Supplied with DIN rail plus neutral & earth terminal blocks.

www.12voltplanet.co.uk

They sell the double-pole breakers too. They are the double-width ones, not the single-width ones Raul described.

 

[mikash]

I am going to be using 48V for my next luton van conversion.

Here is a comparison of just the inverter/charger.

Victron 12v 5000VA 50A multiplus is £1656 from Bimble. and weighs 33KG
Victron 48V 5000VA 70A multiplus is £640 from Bimble and weighs 30KG

Now here is another good bit.

The 12v model has a 50A charger which means it can put in 600 Watts.
The 48v model has a 70A charger which means it puts in 3,360 watts.

What this means to me is that when I go to a hookup, I can charge up much quicker. I will also look at an EV charger adapter.

Finally, the cost of the cables 12v vs 48V soon mounts up both in monetary cost and weight.

The only downside as I see it is having to fit a secondary alternator OR a 48/12V B2B/converter.

With my Luton, I am looking at installing as much as 2KW+ of solar (not decided fully yet). So I may get away without installing a secondary alternator or a B2B.

Victron 12V 5000VA multiplus II charger is actually 220A, not 50A, so difference in charging power is not quite as big but significant anyway.
A dealer also said the 12V 5000VA is only built to order so it may take a while to get one. Has to be a pretty special use case to use so big inverter at 12V. I think 3000VA is already the tipping point where, if building something from scratch you'd probably want to consider 24V minimum.

 

[Gromett]

Victron 12V 5000VA multiplus II charger is actually 220A, not 50A, so difference in charging power is not quite as big but significant anyway.
A dealer also said the 12V 5000VA is only built to order so it may take a while to get one. Has to be a pretty special use case to use so big inverter at 12V. I think 3000VA is already the tipping point where, if building something from scratch you'd probably want to consider 24V minimum.

You are correct I misread that somehow. so it is 2640 Watts vs 3360 Watts. So perhaps not so critical. But those cables to handle 220A vs 70A Ouch!!!

 

[ian27]

You are correct I misread that somehow. so it is 2640 Watts vs 3360 Watts. So perhaps not so critical. But those cables to handle 220A vs 70A Ouch!!!

48v/5000/70 is a really good sweet spot. Charges at 3.3kw which is perfect for slurping EHU juice at max. Cheap - I asked a victron dealer why, they said there is vast stock. 5000VA you really can run pretty much everything you could think of in a MH at the same time. Sane Cable and fuse sizes. c'mon join the 48v club

 

[Raul]

48v/5000/70 is a really good sweet spot. Charges at 3.3kw which is perfect for slurping EHU juice at max. Cheap - I asked a victron dealer why, they said there is vast stock. 5000VA you really can run pretty much everything you could think of in a MH at the same time. Sane Cable and fuse sizes. c'mon join the 48v club

The 48/5000/70 took some time to get UK accreditation for ESS, it's a unit designed for that purpose, easy to retrofit on existing solar as well. It was never intended for mobile applications, but, it can be used in stand alone without grid code.
While the accreditation was taking time, the stock piled up, as no one in UK would buy it. I think only March this year made it, for G98 and G99.
In EU had the accreditation long before, and was selling well there.
I have, and use 3 of these, 2 in parallel on one installation, and one on another installation, but these are static on the house.
One negative on mobile install is the high input current limiter. This unit will limit to min 6A no lower, and if you ever go to a 6A hook up, chances are it will trip it on surges. If power assist boost factor is set to 2, it will try to invert some and cover the surge. This depends on stability of the EHU.
I know them well as they always overload my generator. On a motorhome, you will need a 15kwh battery to warrant a 5kva inverter. Pointless having a 5-10kwh battery hooked up on a 5kva.

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[ian27]

The 48/5000/70 took some time to get UK accreditation for ESS, it's a unit designed for that purpose, easy to retrofit on existing solar as well. It was never intended for mobile applications, but, it can be used in stand alone without grid code.
While the accreditation was taking time, the stock piled up, as no one in UK would buy it. I think only March this year made it, for G98 and G99.
In EU had the accreditation long before, and was selling well there.
I have, and use 3 of these, 2 in parallel on one installation, and one on another installation, but these are static on the house.
One negative on mobile install is the high input current limiter. This unit will limit to min 6A no lower, and if you ever go to a 6A hook up, chances are it will trip it on surges. If power assist boost factor is set to 2, it will try to invert some and cover the surge. This depends on stability of the EHU.
I know them well as they always overload my generator. On a motorhome, you will need a 15kwh battery to warrant a 5kva inverter. Pointless having a 5-10kwh battery hooked up on a 5kva.

thanks raul. I think we agree to disagree to some extent on battery;-). I'm running mine in the MH with 6.4kwh battery and its working well. When I get rid of gas I will put another 6.4kwh in the gas space.

I do take your point about the 6A EHU surge, I have not tried that yet.
If power boost tweak can help solve it, now that Cerbo supports backup/restore of config, its a lot easier to switch to "one you made earlier" than having to get veconfig and a laptop out. I would think also that if given that you have 5000va on tap, there's the option to do your cooking without the ehu connected, or inverter only mode, then use the 6A over night purely as a charger.

 

[Raul]

I think we agree to disagree to some extent on battery;-). I'm running mine in the MH with 6.4kwh battery and its working well.

It may, but, it's not about agreeing. You design for max load to stay with an acceptable C rate, and max for LFP is 0.5C, a 10kwh minimum for that inverter.
Your set up is open for battery abuse, as at some point you will use that inverter at its full power, even if is not intentional.

 

[TheMobileWanderer]

It may, but, it's not about agreeing. You design for max load to stay with an acceptable C rate, and max for LFP is 0.5C, a 10kwh minimum for that inverter.
Your set up is open for battery abuse, as at some point you will use that inverter at its full power, even if is not intentional.

Interesting. I was reading last night about lip and their use for EV. Seemingly they are suitable for c-rate of 5. Maybe reading was prompted from reading tesla 100kW battery can output 5kWH power, which didn't make sense, to me.

So, all I need now is 20 more 48V 5kwh batteries. And a few EV motors, and software.

 

[Raul]

Interesting. I was reading last night about lip and their use for EV. Seemingly they are suitable for c-rate of 5. Maybe reading was prompted from reading tesla 100kW battery can output 5kWH power, which didn't make sense, to me.

So, all I need now is 20 more 48V 5kwh batteries. And a few EV motors, and software.

If you have tesla 5kwh modules, those are not LFP, and I would not have them in a motorhome.
And yes there is high rate EV grade LFP that can do 5C, but, these are sold exclusively to EV manufacturers. What we buy as energy storage, is the basic LiFePo4 that is good for 0.5C charge discharge continuous. Most ppl with prismatic cells design for 0.3C max, that way is impossible to rag them.