Author Topic: Wiring for switching to grid network  (Read 1512 times)

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Offline sebasrodca

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Wiring for switching to grid network
« on: December 11, 2015, 09:00:06 AM »
Hello!

I'm currently designing my own solar plant but I have a situation. I can't afford a bigger capacity to be completely off-grid right now, but I'd like to start with something to learn. The question is, how can I switch to the grid again when the batteries charge run out automatically?

Thank you for your help!

Sebastian

Offline David HK

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Re: Wiring for switching to grid network
« Reply #1 on: December 11, 2015, 06:01:36 PM »
You may not receive much assistance from Forum members unless you can declare what action you have taken (or propose to take) to contact you local electricity supplier for all the technical detail  they will require before a licence is issued for a connection.

The requirements are likely to be very onerous and there is also the matter of insurance cover.

Just thinking that you can build something and connect to the 'grid' as you please could result in you killing someone. What happens if the grid is de-energised and your still pumping electricity into it?

The switching gear arrangement will be of great interest to the electricity company.

Dave

Offline oztules

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Re: Wiring for switching to grid network
« Reply #2 on: December 11, 2015, 07:14:41 PM »
There are ways, and then there are ways.

For a small system, you may be best to make your own internal grid ( you may hook up half a dozen energy users to an inverter), and use a ups solution.

Ie use an extension lead and power boards to drive your loads from the inverter direct, and get a inverter that does UPS function ( not PJ... very suspect in that orientation). That way, when ever your battery is down, the inverter just switches in the grid, and bypasses the ups inverter during those times battery power is low.... some inverters will try to charge the batteries as well at this time... if you want?

This circumvents any official complaints, as thats how you use your computer UPS as well.

Wiring to the fuse box is a different matter entirely, and you will need a double pole double throw switching arrangement... simple and effective.
Using a double throw double pole switch/relay, makes it impossible to power the grid from the inverter, as it never sees the mains connection.... and a PJ could be used in this circumstance, as it is just being asked to be an inverter, and nothing else.

Will probably need a licenced elec to wire it in, and  labelled switch gear with approvals..... depends what country you are in as to how much grief you will cause if your inverter is not UL listed etc. Most of the world will probably not care, but developed countries may be problematic with insurance etc..... they love red tape.

............oztules
Flinders Island...... Australia

Offline sebasrodca

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Re: Wiring for switching to grid network
« Reply #3 on: December 13, 2015, 04:59:08 PM »
Thank you so much for your answers! I'm already buying the inverter with UPS function! Very good suggestion!