Inverter changeover switch.

[Callum4878]

Hi all,

fitted a new Combimaster inverter yesterday and don’t like the idea of it running 24/7 even when on shore power. Would like to be able to switch from mains to inverter at will, especially at night. I know I will need the inverter on to top up my batteries, but i’m thinking I can extend the working life of the inverter by doing this. Any thoughts on a possible changeover switch/procedure? Obviously it would have to be one or the other and never both, so some kind of 2 pole changeover?
Keith

[nicknorman]

This is a bad idea and completely pointless. When on shore power, put the inverter switch to O. This turns off the inverter function but leaves the charger function operating and passes the mains input through to the output. If you disconnect the Combi output by means of your switch, it will make no difference to what is powered up inside the Combi.

 

edit, perhaps you are proposing to disconnect the input too? In which case you’d need 2 switches, ne for input and 1 for output. Our Combi has been on permanently for 10 years, mostly on charger only mode.

Edited October 17, 2020 by nicknorman

[Tony Brooks]

5 minutes ago, Callum4878 said:

Hi all,

fitted a new Combimaster inverter yesterday and don’t like the idea of it running 24/7 even when on shore power. Would like to be able to switch from mains to inverter at will, especially at night. I know I will need the inverter on to top up my batteries, but i’m thinking I can extend the working life of the inverter by doing this. Any thoughts on a possible changeover switch/procedure? Obviously it would have to be one or the other and never both, so some kind of 2 pole changeover?
Keith

You may be wrong about that. Electronic equipment tends to more reliable if its not subject to on - off - on - off operation. Nowadays solid state is far better than valve equipment was there are still issues.

 

Unless your batteries are faulty or your electricity use is excessive for battery bank size I don't see why you can't just turn it off at night. Very little electricity is used while you are asleep even if you have a fridge running. If you turn the mains supply to the inverter off the charge will also be turned off. If you intend to switch the inverter to charger only then it will still be powered up.

 

Does that inverter have the capacity to supplement low current shore line posts when a higher current is required? If so you would limit the appliances that can be run with the shoreline on and inverter turned off. However there are both automatic and manual switches that allow you to supply either shore line derived or inverter derived mains power to the boat's circuits but I don't see how those allow you to charge the batteries with the inverter turned off.

 

 

[Callum4878]

Just having something on at night that's not really needed is alien to me, and I would like the ability to turn it off. The Combimaster cannot be simply switched off, as the mains power runs through it, and it can only be switch to inverter or charge. My intention is to have two feeds to my distribution board shore/inverter and be able to switch between them. Leisure batteries total 630Ah and would only drop a few % overnight, and my 230v equipment comes nowhere near my shore capacity.

Another reason for this decision is on the recent failure of my Mass Combi inverter I had to rewrite my distribution board somewhat to get my socket outlets back on, as everything goes through the inverter. A similar changeover weiuuuld eliminate this. 
I would prefer a simple manual switch, anyone used anything like this? A simple 2pole switch would do I think.

[GUMPY]

To fully switch it off you will need to disconnect the DC supply as well.

 

Do you really want your batteries to go through the full charge cycle every day when you turn the charger back on?

 

All you will do is duplicate the bypass relay that is within the combi.

 

It really isn't worth the effort 

 

As Tony says switching electronics on and off shortens its working life.

Edited October 17, 2020 by Loddon

[Alan de Enfield]

1 hour ago, Callum4878 said:

I know I will need the inverter on to top up my batteries,

Are you proposing to use the inverter to charge your batteries ?

or

Do you mean that you will use the battery charger feature of the Combi ?

 

28 minutes ago, Callum4878 said:

Another reason for this decision is on the recent failure of my Mass Combi inverter

 

I wonder if there was a specific reason why, when your prevous combi failed, that you did not take the opportunity to up-grade to separate charger and inverter ?

[Tony Brooks]

5 minutes ago, Alan de Enfield said:

Are you proposing to use the inverter to charge your batteries ?

or

Do you mean that you will use the battery charger feature of the Combi ?

 

 

I wonder if there was a specific reason why, when your prevous combi failed, that you did not take the opportunity to up-grade to separate charger and inverter ?

I wondered that as well but suspect he may be running a mains fridge so replaced like for like and now feels he needs to complicate things to make it conform to the bees in his bonnet.

 

Seems a bit odd to choose complicated  equipment and then seek to complicate it further when an opportunity to de-complicate things occurred.

Edited October 17, 2020 by Tony Brooks

[Phoenix_V]

We did this. Our Victron doesn't allow to switch off the charger function whilst still keeping power to the 240v sockets and I didnt like the thought of the charger  being on permanently (solar keeps the batteries topped up when we are not there and not using 12v) Also it does use electric. Changeover switch on the input side with centre off works fine.

thread here note the comments re earthing https://thunderboat.boards.net/thread/1041/switching-victron-output-shoreline

Edited October 17, 2020 by Phoenix_V

[Alan de Enfield]

3 minutes ago, Tony Brooks said:

I wondered that as well but suspect he may be running a mains fridge so replaced like for like and now feels he needs to complicate things to make it conform to the bees in his bonnet.

 

Seems a bit odd to choose complicated  equipment and then seek to complicate it further when an opportunity to de-complicate things occurred.

 

I wonder if (assuming he is not a liveaboard) if he turns the electic off in his house every night ?

I cannot think of any house dwellers that I know that do.

[nicknorman]

31 minutes ago, Callum4878 said:

Just having something on at night that's not really needed is alien to me, and I would like the ability to turn it off. The Combimaster cannot be simply switched off, as the mains power runs through it, and it can only be switch to inverter or charge. My intention is to have two feeds to my distribution board shore/inverter and be able to switch between them. Leisure batteries total 630Ah and would only drop a few % overnight, and my 230v equipment comes nowhere near my shore capacity.

Another reason for this decision is on the recent failure of my Mass Combi inverter I had to rewrite my distribution board somewhat to get my socket outlets back on, as everything goes through the inverter. A similar changeover weiuuuld eliminate this. 
I would prefer a simple manual switch, anyone used anything like this? A simple 2pole switch would do I think.

You’ve fitted a Combi but don’t want the features of a Combi! You would need either 2 2 pole changeover switches, or one 4 pole changeover switch because you’d need to switch both the input and the output for the Combi if . Plus, as has been mention, the device is still active if the 12v connections to the battery are kept. The on/off switch on the Combi is a software switch, it doesn’t disconnect anything physically.

 

When you disconnect the 12v, the very large input capacitors discharge. Then when you reconnect it, there is a massive surge (1000A or more) as the capacitors momentarily present a short circuit. Doing this repeatedly isn’t going to do anything for device life.

 

I hear what you say about not wanting to leave stuff on overnight, but that is how the system is designed to be used. It is not designed to be used on and off repeatedly. You are making a common mistake which is to try to reinvent the wheel differently. I would advise against it.

1 minute ago, Phoenix_V said:

We did this. Our Victron doesn't allow to switch off the charger function whilst still keeping power to the 240v sockets and I didnt like the thought of the charger  being on permanently (solar keeps the batteries topped up when we are not there and not using 12v) Also it does use electric. Double pole changeover switch on the input side with centre off works fine.

thread here https://thunderboat.boards.net/thread/1041/switching-victron-output-shoreline

 But then surely there is mains voltage present on the Combi output? And 12v present on the Combi DC input, keeping the microprocessor powered. The whole point of a Combi is to be left on permanently.

[Phoenix_V]

18 minutes ago, nicknorman said:

 

 

 But then surely there is mains voltage present on the Combi output? And 12v present on the Combi DC input, keeping the microprocessor powered. The whole point of a Combi is to be left on permanently.

with combi switched off with it's own switch there is no mains on output, yes 12v still present on input

[nicknorman]

1 minute ago, Phoenix_V said:

with combi switched off with it's own switch there is no mains on output, yes 12v still present on input

But surely if the output is connected to the boat systems there must still be mains present on the output unless you put a switch in there? To what extent that permeates into the Combi I don’t know, but clearly the system isn’t designed to have mains on the output and both no mains on the input, and the inverter section off.
Anyway, your Combi has an on - off - charger only switch, whereas the OP’s only has what is effectively on or charger only. There is no off position.

[blackrose]

1 hour ago, Callum4878 said:

Just having something on at night that's not really needed is alien to me, and I would like the ability to turn it off. The Combimaster cannot be simply switched off, as the mains power runs through it, and it can only be switch to inverter or charge. My intention is to have two feeds to my distribution board shore/inverter and be able to switch between them. Leisure batteries total 630Ah and would only drop a few % overnight, and my 230v equipment comes nowhere near my shore capacity.

 

 

So you want to switch the battery charger part of your combi off at night too? How odd. My separate charger just stays switched on while on shore power. Most people don't switch them off at night.

 

If the batteries are only a few % down in the morning is it good for them to be cycled from that high SoC every day? Ideally I thought it's better if they're less than 95% charged before they're charged up again.

Edited October 17, 2020 by blackrose

[Alan de Enfield]

5 minutes ago, blackrose said:

So you want to switch your battery charger off at night? How odd.

 

Thinking about it, my Father (in his 90's) is similar. there must be nothing either connected or switched on when he goes to bed. Even his buggy with a smart charger has to be switched off overnight and then switched back on in the morning when he can 'keep an eye on it'.

 

Maybe Callum is of a similar generation where electricity was not understood or trusted.

[Phoenix_V]

53 minutes ago, nicknorman said:

But surely if the output is connected to the boat systems there must still be mains present on the output unless you put a switch in there? To what extent that permeates into the Combi I don’t know, but clearly the system isn’t designed to have mains on the output and both no mains on the input, and the inverter section off.
Anyway, your Combi has an on - off - charger only switch, whereas the OP’s only has what is effectively on or charger only. There is no off position.

The mains out is switched off by the switch on the inverter and the input is disconnected by the changeover switch from the incoming mains. I really didnt want to leave a powerful battery charger connected to the batteries when away for several months (even longer this year) I agree no point just for switching off overnight. For the OP you are right he needs some way to switch the inverter function off;  if  he set it to charger only and disconnected the mains input as per my switch wiring would that not have the same effect?

Edited October 17, 2020 by Phoenix_V