Change over switch

[Cush]

So, I am considering using a change over switch to select between ehu or inverter from a powerbank.

youtube and websites have been educational. Learning about auto change over relays and selector switches.
on my power distribution unit (schematic attached. Mine’s the Cheyenne one) there are two separate 240v outputs to sockets and lights etc which I assume would need two relays?

now learning if it’s possible / how to safely install and use a change over switch or relay on the 240 input side. learning about rcd! If you have a good site or channel to recommend, happy to know

merry Christmas nollick ghennal
Cush

if you can’t be with the ones you love, love the ones you’re with

 

[EuroTrotters]

I’ve done this 4 times now twice with contracters, once through a relay and now via a sterling auto changeover, this also uses a contactor. This is via a Victron 2kva inverter

This always involves a new consumer unit and wiping out chargers and fridge on the inverter side.

Next time, I will simply for a 3kva inverter with the auto change over and two separate outputs.

 

[EuroTrotters]

This was the late Andy’s relay option

Auto changeover relay for inverter

First picture is a selection of relays from RS components. The one on the right is my choice as it is 10 amp rated through the normally closed contact set which will be used for the inverter when off hook up. The normally open contact set is 30 amp rated and will be used to power a skt/skts as...

www.motorhomefun.co.uk

 

[autorouter]

This always involves a new consumer unit and wiping out chargers and fridge on the inverter side.

This is true for most installations, especially where the inverter is running from the leisure battery. But not all. For the OP, I believe from previous threads that he is trying to install a power pack (lithium battery, inverter and charger) so that it acts as an alternative supply to the EHU when off-grid. The main reason for doing this is to charge the leisure battery from the power pack.

If so, I would suggest a manual switchover on the mains inlet side, so that the user is always in full control. It's too easy to forget if there's auto switchover, and end up with a drained power pack. However it's also easy to forget to switch over manually, so there's a case for either I suppose.

The reason for separating out some of the mains circuits is that in most installations there are some things that you never want to run from the inverter, because it is usually powered from the leisure battery. For example the mains battery charger. You don't want the inverter to run the charger which charges the leisure battery which powers the inverter. Also some items like the heater and water heater elements will rapidly run down the leisure battery, or a power pack.

Another consideration is an auto-switching 3-way fridge. Usually if the fridge sees a mains supply, it switches to mains with the highest priority. A 3-way fridge element is quite power-hungry, and will flatten a leisure battery or power pack in a few hours. It's easy to forget to switch over manually to gas.

So there are various reasons why there should be switching some of the mains outputs of the mains distribution box, but not others. The outputs come from 3 MCBs, through two 3-way sockets. So the details of separately switching them is a bit complicated. And it may not be better in practical terms than switching on the inlet side.

 

[tacr2man]

If you are in effect using a powerbank in place of a generator You could use an auto changeover switch wired in after the input socket eg

Switch Automatic Transfer Switch Generator Changeover Switch Auto/Manual | eBay

The sudden power cuts have caused a lot of distress. This double power automatic change-over switch will help you to solve this problem. Circuit Type: 2-way. Conversion Mode: Self-cast. 1 x Double Power Automatic Change-over Switch.

www.ebay.co.uk

A standard 3 pin plug on a fly lead could plug into the powerbank . The acs can be set to auto or manual and to prioritize EHU . I would suggest suitable electrician for the install.

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[Cush]

For the OP, I believe from previous threads that he is trying to install a power pack (lithium battery, inverter and charger) so that it acts as an alternative supply to the EHU when off-grid. The main reason for doing this is to charge the leisure battery from the power pack.

yes, that’s the one

I would suggest a manual switchover on the mains inlet side, so that the user is always in full control

The reason for separating out some of the mains circuits is that in most installations there are some things that you never want to run from the inverter, because it is usually powered from the leisure battery. For example the mains battery charger. You don't want the inverter to run the charger which charges the leisure battery which powers the inverter. Also some items like the heater and water heater elements will rapidly run down the leisure battery, or a power pack.

Another consideration is an auto-switching 3-way fridge. Usually if the fridge sees a mains supply, it switches to mains with the highest priority. A 3-way fridge element is quite power-hungry, and will flatten a leisure battery or power pack in a few hours. It's easy to forget to switch over manually to gas.

that all makes complete sense. Thank you.