Bridging the gap...

[Priapus]

I'd like to bridge the gap during load shedding.

By this I mean the following in my house needs to run for a min of 4.5 hours

1. Plugs,
2. Lights,

I don't need the pool pump, AC, geyser or stove to run during these times.

I'd want a system that I can build on, over the years. Start small (Ie batteries / inverter) and move up to solar panels and being almost completely off the grid.

To start with, I figured an inverter wired to the DB board and a couple of 200ah 12v batteries should give me roughly 4hrs of uptime (if my consumption is less than or around 1Kwh )

Someone showed me this inverter - which has inputs for battery and solar when I want to eventually upscale to that.

I'm told that I cannot go to the DB directly without a change over switch due to complacence and insurance; thing is I don't want a manual change over switch as this defeats the point (No power when I am not at home)

So I guess the questions I have are these:

1.Where would I get an automatic change over switch for the DB board?
2. Do I need to install another DB board? (Current board as no space left)
3. Do I need to have a professional install and certify the system; or can I get it certified on its own for insurance purposes

Appreciate any help and assistance on this.

 

[TheChamp]

1.You don't need an automatic changeover switch, most inverters has that built in, just buy a proper inverter.
2. No, you don't need another board, your backup can be integrated onto your existing board.
3.Yes, get a professional to do it and get it certified.

If you have to install the changeover switch the professional will know what's needed.

 

[Priapus]

1.You don't need an automatic changeover switch, most inverters has that built in
2. No, you don't need another board, your backup can be integrated onto your existing board.
3.Yes, get a professional to do it and get it certified.

Thanks. I was under the impression that even though the inverter does the changeover; I still need a switch at the DB board to meet compliance?

 

[TheChamp]

The recommended inverter is fine, start with a big one, you will spend more but it's the only way you will be able to expand the system. It's a 48V system so perhaps it's better just to get a 48V lithium ion battery instead.

 

[TheChamp]

Thanks. I was under the impression that even though the inverter does the changeover; I still need a switch at the DB board to meet compliance?

I am not aware of that requirement, many installs I have seen that does not have the changeover switch, but I am not a professional so perhaps it differs between places, I don't know.

 

[Saba'a]

Please keep us up to date.

I am torn between buying 6.5kva (5000W) generator

OR

Start with inverter as you have. Then add battery/batteries and then eventually solar panels.

 

[Saba'a]

Another thread you may find useful?

https://r.tapatalk.com/shareLink/to...&share_fid=11467&share_type=t&link_source=app

[/URL]

 

[maumau]

Please keep us up to date.

I am torn between buying 6.5kva (5000W) generator

OR

Start with inverter as you have. Then add battery/batteries and then eventually solar panels.

Nay, nay, nay, nay, nay to the generator. Go for the inverter it's a far more elegant solution.

No good reason, just my opinion.

 

[Saba'a]

Nay, nay, nay, nay, nay to the generator. Go for the inverter it's a far more elegant solution.

No good reason, just my opinion.

It is but generator immediate relief.

Inverter ... have to invest in it piecemeal ... so will take a while as you need 8x200AH batteries or 16x100AH batteries (price of one battery lithium ion = 6.5kva generator).

But yes long term makes more sense ... on the other hand generator can be used as backup charger for batteries.

 

[Priapus]

Another thread you may find useful?

https://r.tapatalk.com/shareLink/to...&share_fid=11467&share_type=t&link_source=app

[/URL]

Thanks for that. All I get out of that thread is that I need a second DB.

I'll document my process here; I need to start with understanding what is required in terms of the law and then go from there.

 

[TheChamp]

Thanks for that. All I get out of that thread is that I need a second DB.

I'll document my process here; I need to start with understanding what is required in terms of the law and then go from there.

What informs the need for the second DB? I can't open the link.

 

[Priapus]

What informs the need for the second DB? I can't open the link.

Inverter and battery backup for 3 Phase (Residential)

Any forumites out there with a 3 Phase inverter? or 3x Single Phase inverters - or even just 1x Single Phase inverter as a backup for a few plugs in the house? Would like to know details of your installation, supplier, installer etc (especially in JHB) and any advice you have to offer. I'm...

mybroadband.co.za

 

[TheChamp]

Inverter and battery backup for 3 Phase (Residential)

Any forumites out there with a 3 Phase inverter? or 3x Single Phase inverters - or even just 1x Single Phase inverter as a backup for a few plugs in the house? Would like to know details of your installation, supplier, installer etc (especially in JHB) and any advice you have to offer. I'm...

mybroadband.co.za

I think you are being confused by the 3 phase discussion going on there, yours is a single phase installation, right? Here are the regulations and I see nothing about a separate board, I have seen a couple of installations and nothing about a separate board. But again I am not an expert so do continue your research, I just don't want you to make unnecessary expenses on something you don't need.

 

[TheChamp]

General requirements

SANS 10142-1:2012

7.12.2 Requirements for alternative sources of supply
7.12.2.1 Where any form of alternative supply (emergency supply, UPS etc.), is connected to an electrical installation, a notice to this effect shall be displayed at the main switch of the installation, and where such supply
a) supplies power only to certain circuits in a distribution board, a power-on indicator (visible or audible) shall be provided on each such distribution board as well as a notice indicating that the standby power main switch shall also be switched off in an emergency,
b) only supplies a part of the electrical installation, the notice shall also be displayed on each distribution board in that part of the installation (see 6.6.1.1(d)).
7.12.2.2 The means of excitation and commutation shall be appropriate for the intended use of the generating set and the safety and proper functioning of other sources of supply shall not be impaired by the generating plant.
7.12.2.3 The prospective short-circuit current and prospective earth fault current shall be assessed for each source of supply or combination of sources, which can operate independently of other sources or combinations. The short-circuit rating of protective devices within the installation and, where appropriate, connected to the main supply, shall not be exceeded for any of the intended methods of operation of the sources.
7.12.2.4 Where the alternative supply is intended to provide a supply to an installation that is not connected to the main supply, or to provide a supply as a switched alternative to the main supply, the capacity and operating characteristics of the alternative supply shall be such that danger or damage to equipment does not arise after the connection or disconnection of any intended load as a result of the deviation of the voltage or frequency from the standard range. Means shall be provided to automatically disconnect such parts of the installation, as may be necessary if the capacity of the alternative supply is exceeded.
7.12.2.5 Where an alternative supply is provided to an installation or part of an installation as a switched alternative to the main supply, the change-over switching device shall disconnect the main supply before the alternative supply is switched in. The change-over switching device shall be interlocked in such a way that the main supply and the alternative supply cannot be connected to the installation or part of the installation at the same time.
7.12.2.6 Except where otherwise permitted in this part of SANS 10142, where a socket-outlet is installed in a circuit on standby power, such circuit shall be protected by an earth leakage protection device with a rated earth leakage tripping current (rated residual current) I∆n not exceeding 30 mA.
7.12.2.7 A 230 V generator with a V-O-V earth connection (centre tap on winding which is earthed), shall not be connected to a fixed electrical installation.
Note: Such a generator may be used as a free-standing unit to provide power to specific appliances (author’s emphasis).

 

[TheChamp]

As you can see it just states that the main box should be labelled accordingly.

 

[Gordon_R]

As you can see it just states that the main box should be labelled accordingly.

It may not be a specific requirement, but practically speaking it is much simpler to install a new box, than to try to squeeze all of the new components and labels into an existing DB.

It is also a lot safer if the inverter is in another room, so that the sub-DB can be in close proximity.

 

[Priapus]

It is also a lot safer if the inverter is in another room, so that the sub-DB can be in close proximity.

I am planning on having the inverter and the new DB in an outbuilding where there is space. Would there be an issues to this?

 

[Priapus]

I think you are being confused by the 3 phase discussion going on there, yours is a single phase installation, right? Here are the regulations and I see nothing about a separate board, I have seen a couple of installations and nothing about a separate board. But again I am not an expert so do continue your research, I just don't want you to make unnecessary expenses on something you don't need.

Thank you, I might be mistaken and will continue doing more research.

 

[Brontosaurus]

I am planning on having the inverter and the new DB in an outbuilding where there is space. Would there be an issues to this?

Depends. Do you have access to the main power source from this outbuilding coming into your house? If so, then no issues.

My setup is in my garage where my main db is. I have a separate one with my lights and plugs on which is connected to the inverter.

I run a 3KVa 24V (4x 12V batteries, running 2x parrallel, 2x series) system which I honestly would not recommend. As mentioned by thechamp above, rather go for 5KVa or bigger with 48V. My reasoning though is because my house was wired by Stevie Wonder, and I have about 8 plugs on one live which just happens to have all the appliances on (with the exception of my kettle) which is connected to the inverter, so my system often overloads and the inverter screams like a banshee (even though it's set to bypass on mains when overloaded).

 

[TheChamp]

Depends. Do you have access to the main power source from this outbuilding coming into your house? If so, then no issues.

My setup is in my garage where my main db is. I have a separate one with my lights and plugs on which is connected to the inverter.

I run a 3KVa 24V (4x 12V batteries, running 2x parrallel, 2x series) system which I honestly would not recommend. As mentioned by thechamp above, rather go for 5KVa or bigger with 48V. My reasoning though is because my house was wired by Stevie Wonder, and I have about 8 plugs on one live which just happens to have all the appliances on (with the exception of my kettle) which is connected to the inverter, so my system often overloads and the inverter screams like a banshee (even though it's set to bypass on mains when overloaded).

The problem is that the inverter is limited to its rated power, if it's 3kW it does not matter if you pulling from the mains or solar, it has reached it's limit, the mains is there but you cannot use it to its full potential, think of it as a circuit breaker, it does not matter if you have 60 amps from the Mains supply, you just won't be able to pull off more than what the circuit breaker allows.