Fsk Eskom

[kimbo]

I would like to start a thread to see what ppl have done to dodge load shedding

I am getting a 1.4kW inverter and coupled with 2 x 65amp batteries running in 24 Volt this system would be good for most of the stuff in the house. I am not running the geyser and stove.

Because this is modified sine wave implements that have motors inside will not like it very much, and in the research i done seems like some plasma tv's dont like them ether.

 

[kimbo]

The first thing the ppl tell you to work out is your watt/hour usage. This is how i look at it, @johan please tell me if i am doing this wrong

Look at the back or on the bottom or the device the should be a sticker with that info. Remember that is the watts it will use in one hour. So rather take that amount and multiply it by the time you will use it

So for instance a toaster at 1500 watt used for 5 minutes
so 1500 divide by 60 to get the watt per minute
25watt
35 watt multiply by 5min
125 watt

So to get our house watt/hour usage i checked the utility bill

We use on average 650 units of power a month
That is 650 kW per month
650 divide by 30 to get the per day average
22kW per day
22 divide by 24 to get the per hour kW
0.92 kW or 920 watt per hour

Ok so the 1.4kW inverter will be okay

Now for the batteries
You must decide 12 volt or 24 system
Both have their pros and cons but the biggest for me the 24volt system you dont run the battery so hot deu to lesser amps (i will explain now)

​

Most of us know that amps are the stuff that give electricity its kick. The more amps you get the stronger the current. So in a 12volt system that 200amps looks very inviting for your "FSK Eskom" system but be aware that there will be more amps between the batteries and from the batteries to the inverter as well. To handle this you will need a thicker gauge wire and wire that can handle 200 amps is kinda thick. So you will have to use it between the batteries and then to your inverter

On a 24volt system you will not need that thick wire because your batteries are connected in Series so the volts gets added but the amps stay the same (actually the amps gets halved). your batteries will last you longer as well because there is less heat and heat is not a friend of batteries

On my system i opted for a 24 volt system

Now to work out the batteries i will need to handle my 940 watt per hour

Okay as this is a load shedding system for a start i would it to run for at least two hours

940 x 2 = 1880watt

To work out the watts from a battery you need to multiply the amps with the volts

In my system it is 24volt x 100amp
2400watt

Remember it is not good for a battery to be drained all the way, rule of thumb is 50% so if i need 1880 watt i need 3760watt of battery power
But the deep cycle can be run down a bit further so 2 x 100amp should be doing ok

But that 940watt is including the stove and geyser and fridge and so. Things i will not need to run for that time

so the 2 x 65amp deep cycle batteries will be fine. Later i can just add more batteries is i need mre time of the grid, just remember you have a 24 volt battery aray, so you will need to add two 12 volt batteries at a time

 

[johan]

A toaster rated 1500W draws 1500W irrespective of how long its switched on, it can't draw less than 1500W @kimbo. The rest looks good. What most do, is to add everything up that needs to run from UPS/Inverter, and add a safety margin of 35%.

example:

Desktop PC ........ 650W
10 x 10W LED lights ........ 100W
Electric fence ........ 50W
Outside lights ........ 200W
Total ........ 1000W
Safety margin ........ 350W
UPS/Inverter required ........ 1350W

PS. Also remember that any UPS/Inverter's energy efficiency is at the absolute best 90%, so you need to factor that in as well, plus some losses over the cables and connectors.

 

[kimbo]

Thank you @johan

Understand about the toaster, you need the 1500watt to heat up the element, stupid mistake sorry

 

[zadiac]

Very informative. Thanks @kimbo and @johan
Will definitely keep all this in mind when I start buying stuff for my system.

 

[kimbo]

Been a wile since i posted here:

After waiting a long time the electrician installed my inverter. It took him about two hours to rewire the DB board the way i want it.

1.4 kW inverter and 2 x 150 amp batteries



Today was the first test of the system. We had load shedding from 12:00 to 14:15

This was just before the power went out, all systems go



Power just went out and all is well



1 hour into load shedding



2 hours into load shedding, the fridge just came on



The power just came back. Two hours and fifteen minutes



I am very happy with this, my pc and all the lights and the fridge and freezer is on it

oh and my ADSL

 

[Silver]

Been a wile since i posted here:

After waiting a long time the electrician installed my inverter. It took him about two hours to rewire the DB board the way i want it.

1.4 kW inverter and 2 x 150 amp batteries

View attachment 32079

Today was the first test of the system. We had load shedding from 12:00 to 14:15

This was just before the power went out, all systems go

View attachment 32081

Power just went out and all is well

View attachment 32082

1 hour into load shedding

View attachment 32083

2 hours into load shedding, the fridge just came on

View attachment 32080

The power just came back. Two hours and fifteen minutes

View attachment 32084

I am very happy with this, my pc and all the lights and the fridge and freezer is on it

oh and my ADSL

That is amazing @kimbo
Looked like your electrician was ready for combat (against Eskom I presume) he he
Super, thanks for the photos.
So I assume it all just works without you having to do anything?
Do you have to turn off the geyser? Or did he wire it so that you dont do anything?
Reason I ask is i am keen to get something similar

 

[kimbo]

That is amazing @kimbo
Looked like your electrician was ready for combat (against Eskom I presume) he he
Super, thanks for the photos.
So I assume it all just works without you having to do anything?
Do you have to turn off the geyser? Or did he wire it so that you dont do anything?
Reason I ask is i am keen to get something similar

@Silver lol @ combat

No you dont switch any thing, the inverter is connected straight to the DB board, which is basically wired in two. One circuit for the stuff that just use Eskom power like the geyser and everything in the kitchen
The next circuit is the stuff that will run of the inverter when the power is cut, like the lights and outside lights, my room (PC ADSL WIFI and so) my moms room (her TV and bed side lamp)
The inverter switches automatic to battery when the Eskom power is cut, you cant even see the change over (think it's 85ms or something)

 

[annemarievdh]

This looks like a much better alternative than having a generator making a lot of noise. How much are we looking at when getting something like this. @kimbo

 

[kimbo]

This looks like a much better alternative than having a generator making a lot of noise. How much are we looking at when getting something like this. @kimbo

About 8k for a small system

 

[Silver]

Thanks very much @kimbo
Well explained
I understand now

Thanks for that, i need to get one of these setups

Just a few questions if you dont mind
1) how big are the batteries and where do you put them?
2) does the inverter unit have to be in the same spot as the batteries? Or can the batteries be somewhere else? I assume then wiring is needed
3) does the system make any noise when in battery mode? I mean, is it quite distracting? I need silence when i work so maybe i can put it in a cupboard and wont hear it.

 

[kimbo]

Thanks very much @kimbo
Well explained
I understand now

Thanks for that, i need to get one of these setups

Just a few questions if you dont mind
1) how big are the batteries and where do you put them?
2) does the inverter unit have to be in the same spot as the batteries? Or can the batteries be somewhere else? I assume then wiring is needed
3) does the system make any noise when in battery mode? I mean, is it quite distracting? I need silence when i work so maybe i can put it in a cupboard and wont hear it.

1. @Silver the system is flexible. So you add batteries for the longer you want to stay of the grid. You will have to work out your requirements like i did in the OP, i have the 150 amp batteries. They are quite big, truck batteries
2. because your are running such big amp load between the batteries and the inverter try to keep the distance between the batteries and the inverter as small as possible. You have to run thick cables from the batteries to the inverter, so if you have a distance to go you will have quite a voltage drop
3. Yes, it does have a fan in that stay on the whole time, i believe you get other makes that the fan only come on if necessary. We opted for it to stay in the kitchen. Close to the DB board and far enough from the rooms so that the fan dont bother us at night. You might want to rethink the cupboard idea. Apart that the batteries are very heavy (about 80kg for one) they dont like closed spaces, batteries need to breath. They are sealed batteries so no toxic fumes will come from them but the need cool air over them

 

[Silver]

Thanks @kimbo
Most helpful

PS - Lol, i chuckled about the voltdrop. Almost asked you if that was under load? You need to use very thick wire - and preferably kanthal. Ha ha

 

[kimbo]

Thanks @kimbo
Most helpful

PS - Lol, i chuckled about the voltdrop. Almost asked you if that was under load? You need to use very thick wire - and preferably kanthal. Ha ha

lol

 

[kimbo]

Thanks @kimbo
Most helpful

PS - Lol, i chuckled about the voltdrop. Almost asked you if that was under load? You need to use very thick wire - and preferably kanthal. Ha ha

What some ppl do is have the whole system in the garage and just run a wire from there to the DB box. From the inverter to the DB box you dont need a thick cable but mind the distance dont over do it

 

[Silver]

Thanks very much @kimbo
Much appreciated

 

[Noddy]

Use welding cable between batteries and invertor

 

[kimbo]

Use welding cable between batteries and invertor

That is what i have

 

[Rob Fisher]

Happily my DB board is in my garage where my system is... the fan is a little too noisy to be in the house!

 

[wazarmoto]

I've got the tedelex intellipower. Bought it 8 years ago for my old Vodacom 4u store. When I sold the business they didn't want the unit so I took it home. Usually runs my TV (42" lcd), hp microserver with 4 hard drives inside, DSTV, home theatre, ps4 and adsl. Runs at least 8-10 hours. That was the longest my powers been gone. It all depends on how much tv I watch though. But I've decided to connect it to my dB board and connect it to my lights and just the one power Point so I'll have enough to run my adsl and charge my phones. And maybe bedroom tv if I need. Lol. But yeah, these inverters are epic. I hardly ever use my generator unless my wife and parents next door need it.

 

[Noddy]

Im going to buy a 5000 VA pure sine wave invertor, with solar charge module. Hopefully next year this time, we will be totally off the grid.

 

[kimbo]

Im going to buy a 5000 VA pure sine wave invertor, with solar charge module. Hopefully next year this time, we will be totally off the grid.

nice! @Noddy just make sure, some inverters with a bad efficiency have a high VA (volt hours) but low WA (Watt hours) and they only tell you in the small print

 

[Noddy]

Thanks @kimbo will make sure before buying