Wiring a battery charger and inverter thro the van ring mains?

[MobyDick57]

Good afternoon
Unsure if I have set my first thread up correctly
I have been thinking how can I wire the battery charger and inverter, so that the inverter feeds the van ring mains without effecting the battery charger ( ie so there is no loop).

Should the wiring of the inverter be as follows;

Mains hookup through 240v multiple fuse box.
A 240v supply cable to the Inverter with auto mains switch.
A separate 240v supply cable to the Battery charger - Votronic Triple charger

Inverter
It receives power from the 12v battery and directly from the hookup.
It supplies the ring mains.

Therefore
When the van is on hookup - the inverter automatically switches to mains to supply ring mains. The battery charger receives a separate supply to automatically charge the batteries.

When the van is NOT on hookup and the inverter is on - The ring mains receives 240v mains, however the battery charger DOES NOT RECEIVE 240v mains. Therefore absolutely no possibility of a loop.

Does the above make sense?
or have I got wrong?
All help will be much appreciated

 

[pappajohn]

On inverter just turn the charger off, if should have its own protective breaker in the consumer unit. .
If it can't be turned off you need seperate sockets for the inverter.

 

[MobyDick57]

Hi papajohn,
On my morelo switches automatically, so I do not have to switch anything.
However we also have a camper van and I want to automate it the same

 

[pappajohn]

You

Inverter
It receives power from the 12v battery and directly from the hookup.

That sounds very much like an inverter charger.
If you exceed the hookup amperage the inverter makes up the difference.
I can't see any possible way to isolate the charger.

 

[pappajohn]

Actually, just read the post again and the only way is unplug/disconnect the charger

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[MobyDick57]

My Morelo is wired in a similar way.
Ie imagine an extension lead with two sockets. Plug in the EHU
One socket goes to inverter then ring mains
One socket goes to battery charger (not ring mains

Unplug the extension lead, the inverter switches to DC

plug extension lead in, both get separate 240v

 

[eddie]

Simply interrupt the wire that supplies your 13 amp sockets, and have that as the "input" to the inverter and the "output" re joins the wire (so the inverter is series with the sockets

If it doesn't have a built in automatic transfer switch, use an external mains relay or, buy a switching box.

Don't forget to add a RCD on the output of the inverter as the 13 amp sockets will be post the RCD fitted by the motorhome converter

Or, buy a inverter/charger, and put in series between the 16 amp hook up socket and the distribution board and unplug the existing charger

 

[MobyDick57]

The inverter is a Votronic 1700 with automatic switching and a RCD.
The battery charger is a Votronic triple charger.

 

[tacr2man]

These work well , for auto switch between supply , and can be manually switched as well , just connect charger on 240 ehu side and inverter to other input , ring main sockets to ouput

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[Raul]

Simply interrupt the wire that supplies your 13 amp sockets, and have that as the "input" to the inverter and the "output" re joins the wire (so the inverter is series with the sockets

If it doesn't have a built in automatic transfer switch, use an external mains relay or, buy a switching box.

Don't forget to add a RCD on the output of the inverter as the 13 amp sockets will be post the RCD fitted by the motorhome converter

Or, buy a inverter/charger, and put in series between the 16 amp hook up socket and the distribution board and unplug the existing charger

Surely that first phrase is wrong. It it a inverter charger. The input and output is separated until inverter synchronising with the grid, and then it closes the relay to put output in parallel with the output of the inverter. You can’t energise the output from the same source of input.
Op needs to clarify if he is talking about inverter as separate stand alone 12v feed only, or a inverter charger with AC in.

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[pappajohn]

Op needs to clarify if he is talking about inverter as separate stand alone 12v feed only, or a inverter charger with AC in.

Agreed, the way its explained it appears to be an inverter charger... 12v and mains in.

 

[MobyDick57]

Yes inverter has 12v DC and 240v input

 

[MobyDick57]

The triple charger has solar/alternator/240v input

 

[MobyDick57]

Separate units

 

[EuroTrotters]

I’ve done it many ways in the past.

Manual switch
Relay
contacter

currently working on this

Sterling 32a auto crossover switch issue (tripping RCD)

Hi, can anyone help please ?. I installed a Sterling 32a crossover switching unit. Switches automatically between Shore (EHU), generator or Inverter. All was well, but it meant I had to re-wire the fridge and battery chargers to it’s own MCB. Meaning I had to manually switch off fridge (AES)...

www.motorhomefun.co.uk

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[eddie]

Surely that first phrase is wrong. It it a inverter charger. The input and output is separated until inverter synchronising with the grid, and then it closes the relay to put output in parallel with the output of the inverter. You can’t energise the output from the same source of input.
Op needs to clarify if he is talking about inverter as separate stand alone 12v feed only, or a inverter charger with AC in.

No I was giving the options as I wasn't quite sure which vehicle we are now talking about LOL

If its just an inverter, simply fitting it in series for the 13 amp sockets is the easiest, so an inverter with a built in transfer switch is the easiest DIY install

 

[MobyDick57]

In my case my fridge is 12v only, so no fix units use 240v

 

[MobyDick57]

Eddievanbitz thanks, I not technical but is that as described in my first post?

 

[eddie]

Eddievanbitz thanks, I not technical but is that as described in my first post?

Yup, I was explaining the options

The only thing you didn't mention was an RCD on the load side of the inverter

 

[MobyDick57]

Thanks very much Eddie
And thank you everybody else who joined in with this discussion
I tried to find a wiring diagram on the internet, but to no avail. In this day and age it should be simple to have the above wired automatically without the mystery
Thanks again
Richard

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[autorouter]

I'm not convinced that this inverter has an RCD. It has overload protection and automatic switching. So you will need an RCD or RCBO on the output. Also it's either/or. You can't use the inverter to boost the mains supply like some Victron inverter/chargers for example.

I suggest two RCBOs in the mains consumer unit, one for inverter loads, one for non-inverter loads. Hookup input goes to the non-inverter loads RCBO, and also to the inverter mains input. Inverter output goes to the inverter loads RCBO.

Non-inverter loads include the battery charger, 3-way fridge, water heater and room heater. You don't want the fridge to be running from the inverter, draining the batteries.

The inverter loads will be automatically switched to hookup power when available by the inverter internal relay.

I suggest using RCBOs (ie combined RCD and MCB) because you need two RCDs anyway (for hookup and inverter). Also in the UK it's a bit difficult to find 2-pole MCBs that are required by the regs rather than the common single-pole type.

An RCBO is a bit more expensive than separate RCD and MCB, but since only two are needed (not as in a house which would need a dozen) that's not a big deal.

 

[Raul]

RCBO’s at toolstation for 20 quid each.

 

[EuroTrotters]

No I was giving the options as I wasn't quite sure which vehicle we are now talking about LOL

If its just an inverter, simply fitting it in series for the 13 amp sockets is the easiest, so an inverter with a built in transfer switch is the easiest DIY install

Just be mindful of AbSorbtion refrigerators if they are on the same circuit as your ring main. AES versions will switch to your inverter and drain your battery.

 

[MobyDick57]

Thank you for your help
I am having the inverter replaced due to be faulty at SMC. We have agreed to upgrade the unit to a Votronic 1700 model, However I want the wiring to be automatic ie not have to switch from inverter to EHU plus avoid another switch to avoid a loop.
Thank you everyone

 

[Rustyspanners]

You need a priority relay £70 automatically disconnects from ehu when on inverter. Connect charger on ehu side so it gets no feedback power from invertor.

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[Rustyspanners]

NDS Smart Inverter Priority Switch - Vanhomes

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[eddie]

Much easier to buy an inverter with a built in mains priority switch