Switching between solar and mains

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Switching between solar and mains

Postby SolarJeff » Wed Jan 27, 2016 10:13 am

Ok My solar system feeds into batterys, that I draw power from over night.....

I have a inverter that I plug things into, as long as there is power, but over night I need to cut back and switch some items back to mains power..
At this time I pull a plug out of one power board and then plug it into another....

There has to be a better way???

looking for thoughs on how to get around this problem?? (without adding more batterys)

1. a battery recharger hooked up to the batterys to do some charging when the battery Vol, drops..

2. a switch system, that lets you switch between the two??

I'm open to any thoughts on ways around this..
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Re: Switching between solar and mains

Postby Gordon-Loomberah » Wed Jan 27, 2016 11:23 am

You could do it with timers or automatic transfer switches, but you should use a licenced electrician for switching around 230V sources.

You can charge your battery overnight on lower cost off-peak rates, but there really is no point in doing that- you'd be better off running things directly, and thus avoid the inefficiencies of the charger, and of the Lead-acid charging process. For off-grid solar charging during the day, the use of a Lithium battery would mean you have significantly more energy available at night time, both because of the greater efficiency of Lithium, and also because you can safely discharge them much more deeply, without compromising their life.

Have a read of this thread:

How deeply are you discharging your battery each night?
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Re: Switching between solar and mains

Postby norbert1 » Tue Feb 02, 2016 7:29 pm

I have an electrician's licence but are retired now. But wiring a couple of switches into my meter box was easy.
These are industrial 20A switches, each has 3 positions: Solar - OFF - Mains
One switch is for the lights, the other for the GPO's.
The oven runs only from the mains.

Before I increased my battery bank to 10Kwh lithium I did load shedding like you plan to do.
Another method is to wire a separate power point, fed from the inverter, to your fridge.
A fridge is usually the most power hungry item so by connecting it to the inverter on sunny days and to mains if overcast saves a lot of battery flattening.

Please keep in mind only a licensed electrician can do the wiring for what I suggested above.
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Re: Switching between solar and mains

Postby Tracker » Wed Feb 03, 2016 8:08 am

ATS... Automatic Transfer Switch? .. I use one..

It is a basic relay device with one output and a number of inputs..

Each input is prioritised such that you can set the GRID as the default, but, if the INVERTER is running, then that will be the supply.. or you might have a generator as a third input..

It is the most satisfactory and simple way of doing it.. So you just start the inverters and clunk, you have changed over
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