Using an inverter on an auto change over switch. (13 Viewers)

[Leejohn02]

At present i purchased a changeover switch and have wired it up to the inverter and then to fuse board. The issue i'm having is that when i'm off grid the van is basically trying to charge itself and doing what i believe is called a death loop. I have been looking at current sensing switches but i can't find one with a large enough amperage and connectors for the 12v. I have no way of turning off the transformer/emitter as its being used for everything else as well, and there is no way to isolate the battery charger specifically. Welcome any suggestions , i have attached a photo too show what i mean too, thanks for any suggestions

 

[Cush]

There must be a way to disable the onboard charger. If you can provide details of the power supply unit, someone will be able to help.

Having a quick google, it looks like an EBL 99. Someone one here will know

 

[eddie]

You simply need to ‘move’ the automatic changeover switch to the 13amp sockets.

So default closed would be mains, when inverter is turned on, trans fare switch would ‘switch’ supply to the sockets

Loads of diagrams on the forum if your unsure

 

[DBK]

As Eddie says, the changeover switch should be on the 240v side. You need to find which cable or cables go to the sockets downstream of the consumer unit/RCDs and put the relay there.

In my signature below there's a link to how I did this. The tricky bit was finding the correct relay as I got this wrong initially, not noticing relays can have different ratings for making or breaking the circuit.

I would have a heavy duty manual switch on the 12v supply to the inverter so you can properly isolate it, otherwise it will continue to draw a small current all the time.

 

[TrudeandDall]

Exactly as Eddie says - feed only the socket radial circuits from the changeover switch.

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[Leejohn02]

You simply need to ‘move’ the automatic changeover switch to the 13amp sockets.

So default closed would be mains, when inverter is turned on, trans fare switch would ‘switch’ supply to the sockets

Loads of diagrams on the forum if your unsure

So this is the part i'm not understanding, when i initially tested the RCD and switched it off, the power completely turned off including all the 12v supply, when i press the switch for 12v/230v all the 12v comes on. We only have 1 breaker on the RCD which seems to do everything. The issue is, if i put the power on from the inverter on the 230v rail it blows the fuse on the emitter/transformer in 12v mode. So i need to find a way to cut the power to just the battery charger part from the emitter to the batteries, i could add a manual switch if i really must, but would much rather it be automatic. Hence me thinking a sensor switch could work if i could find the right sized one. I have attached a pic of the emitter we currently have a a digram of the electrical schematics which should hopefully show what i mean

 

[autorouter]

The first picture is of a Reich E-Box. The second picture is a schematic diagram of a Lippert/Schaudt Electroblock EBL99. The two are entirely different electrically, even though they both do much the same job. I don't think you will have both of these fitted into your motorhome. Can you post a picture of your setup, the 12V fuseboxes and the mains consumer unit if there is one?

 

[DBK]

So this is the part i'm not understanding, when i initially tested the RCD and switched it off, the power completely turned off including all the 12v supply, when i press the switch for 12v/230v all the 12v comes on. We only have 1 breaker on the RCD which seems to do everything. The issue is, if i put the power on from the inverter on the 230v rail it blows the fuse on the emitter/transformer in 12v mode. So i need to find a way to cut the power to just the battery charger part from the emitter to the batteries, i could add a manual switch if i really must, but would much rather it be automatic. Hence me thinking a sensor switch could work if i could find the right sized one. I have attached a pic of the emitter we currently have a a digram of the electrical schematics which should hopefully show what i mean



View attachment 957913

View attachment 957914

The inverter has to be connected, through a fuse, directly to the leisure batteries. It can't go through any other part of the 12 volt system as it will take too much current, unless it's a very small inverter like 100W. Anything much bigger and you will need a direct connection.

 

[Leejohn02]

The inverter has to be connected, through a fuse, directly to the leisure batteries. It can't go through any other part of the 12 volt system as it will take too much current, unless it's a very small inverter like 100W. Anything much bigger and you will need a direct connection.

the inverter is connected directly to the lesuire battery, its running on 60cm cables too as i know if needs to be as close to the batteries as possible. It also has an inline Fuse, and i've added a breaker on it too

 

[Leejohn02]

The first picture is of a Reich E-Box. The second picture is a schematic diagram of a Lippert/Schaudt Electroblock EBL99. The two are entirely different electrically, even though they both do much the same job. I don't think you will have both of these fitted into your motorhome. Can you post a picture of your setup, the 12V fuseboxes and the mains consumer unit if there is one?

Sorry wrong image.

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[autorouter]

From what you are saying I think you want to connect the 13A sockets, and nothing else, to the inverter. You also want the 13A sockets to automatically switch to the mains hookup supply when it is connected. All the other items like the battery charger you want to only work from the mains hookup, never from the inverter.

If that is what you want to do, the changeover switch is in the wrong place. You need to find the wire that goes to the 13A sockets from the fuseboard/consumer unit. Then put the changeover switch into that wire. A manual switch would be OK for that - the kind that is used to switch supplies between a generator ans a grid mains supply for example.

However it is possible to use a 20A relay to switch automatically. It can be wired so that the sockets switch to the hookup mains automatically as soon as the hookup is connected. Then it switches back to the inverter when the hookup mains is disconnected.

Usually if it's an EBL 12V distribution/fusebox, that only contains the mains charger for the leisure battery. All the mains wiring is in a separate small consumer unit, with an RCD and some MCBs. The changeover switch needs to go somewhere near the consumer unit.

 

[EuroTrotters]

you either have to have an inverter with two outputs, one when EHU and one on Inveter

An auto change over system will need a consumer unit where you can put the fridge and battery charger on a separate MCB

Ive carried out these wiring upgrades many times, including one from the late Andy (techno I think his username was). This used a relay system, nut was not compatible with the new Victron inverter I installed.

So now I have buzzing contacted version (my Victron does not have dual output but will next time)

 

[fred_jb]

If you used a Renogy inverter most of their models include an automatic switchover which makes it all very simple. With these you need to take the mains input for the inverter from a point supplied by the EHU, but after the master circuit breaker switch/RCD. The mains output from the inverter should go to just the habitation mains sockets which should be put on a separate circuit breaker in your mains distribution box if they are not already.

With that setup, if the inverter senses incoming mains from the EHU it switches off its own 12V generated mains and outputs mains directly from the EHU to anything connected to its output.

If there is no EHU, or if there is but it fails, the inverter automatically disconnects the incoming mains and instead generates its own 240V from the 12V supply, which is why they describe it as having a UPS (uninterruptible power supply) function. If a working EHU supply is reinstated the inverter again automatically switches off its own 240V output and switches over to sending EHU mains to its output.

 

[TrudeandDall]

From what you are saying I think you want to connect the 13A sockets, and nothing else, to the inverter. You also want the 13A sockets to automatically switch to the mains hookup supply when it is connected. All the other items like the battery charger you want to only work from the mains hookup, never from the inverter.

If that is what you want to do, the changeover switch is in the wrong place. You need to find the wire that goes to the 13A sockets from the fuseboard/consumer unit. Then put the changeover switch into that wire. A manual switch would be OK for that - the kind that is used to switch supplies between a generator ans a grid mains supply for example.

However it is possible to use a 20A relay to switch automatically. It can be wired so that the sockets switch to the hookup mains automatically as soon as the hookup is connected. Then it switches back to the inverter when the hookup mains is disconnected.

Usually if it's an EBL 12V distribution/fusebox, that only contains the mains charger for the leisure battery. All the mains wiring is in a separate small consumer unit, with an RCD and some MCBs. The changeover switch needs to go somewhere near the consumer unit.

This is exactly what I did and it works perfectly. The onboard charger and Truma supply are only operational when I (exceptionally) use a EHU. At all other times the relay is not powered by the EHU and the 230v sockets are only live when the inverter is on.