Jump to content

Loadshedding solutions


ChrisF

Recommended Posts

  • Replies 1.1k
  • Created
  • Last Reply

Top Posters In This Topic

Top Posters In This Topic

2 hours ago, johnson said:

Hey guys. I'm a little late in joining the conversation because I haven't been very active on bikehub for the last year or so because of health issues.

Last year November I finally stripped my moer for Eskom. I Got a local solar installer who is highly recommended and very reputable to install a data logger and give me a quote for a installation.

The data logger was in my house for a week to monitor our electricity usage.

I Got the quote and started doing the math. The saving I will make on the electricity bill and the petrol for the generator combined is more than the installment I will have for financing the installation. 

So I pulled the trigger and the solar system was installed early in January.

Today marks one month since I've last had loadshedding.

My solar system consists of the following;

Sunsync 5kw inverter

Sunsync  5kw battery's (X3)

JA Solar 460w solar panels (X14)

solar1.jpeg

solar2.jpeg

solar3.jpeg

solar4.jpeg

This would be my ideal setup as well I think.

Basically the max you can do with a single 5kw inverter without adding MPPT's to directly charge the batteries or another inverter to the mix if my understanding is correct.  You can add more batteries but the load distribution and recharge time will take a nose dive without adding additional charging capacity from the PV side.

Will see how I manage with my upgrade and see if I will need to add-on to the system next year or not.

Link to comment
Share on other sites

4 hours ago, johnson said:

Hey guys. I'm a little late in joining the conversation because I haven't been very active on bikehub for the last year or so because of health issues.

Last year November I finally stripped my moer for Eskom. I Got a local solar installer who is highly recommended and very reputable to install a data logger and give me a quote for a installation.

The data logger was in my house for a week to monitor our electricity usage.

I Got the quote and started doing the math. The saving I will make on the electricity bill and the petrol for the generator combined is more than the installment I will have for financing the installation. 

So I pulled the trigger and the solar system was installed early in January.

Today marks one month since I've last had loadshedding.

My solar system consists of the following;

Sunsync 5kw inverter

Sunsync  5kw battery's (X3)

JA Solar 460w solar panels (X14)

solar1.jpeg

solar2.jpeg

solar3.jpeg

solar4.jpeg

Very nice setup!!

Great feeling to be off the grid

Link to comment
Share on other sites

I have a small inverter and battery set-up that I need to have connected to the DB. This would be to run lights, my PC, Wi Fi, house alarm etc.

The electrician needs cable that aren't in stock and is being vague about what is required.
The cables would run 4m from the garage to the DB (and back again).

I will upgrade the inverter in the near future, so will 'oversize' the cables for this installation.

Can anyone tell me what I need ?
Perhaps I get those cables for him so that he can get going .

Link to comment
Share on other sites

24 minutes ago, splat said:

I have a small inverter and battery set-up that I need to have connected to the DB. This would be to run lights, my PC, Wi Fi, house alarm etc.

The electrician needs cable that aren't in stock and is being vague about what is required.
The cables would run 4m from the garage to the DB (and back again).

I will upgrade the inverter in the near future, so will 'oversize' the cables for this installation.

Can anyone tell me what I need ?
Perhaps I get those cables for him so that he can get going .

I know they used flat but thick cables on ours, 2 only just fit in a 25mm pipe.

 

From my install I think it was this:

image.png.d1437b25ede219fd22c2dd652aacc3f2.png

Link to comment
Share on other sites

21 minutes ago, splat said:

I have a small inverter and battery set-up that I need to have connected to the DB. This would be to run lights, my PC, Wi Fi, house alarm etc.

The electrician needs cable that aren't in stock and is being vague about what is required.
The cables would run 4m from the garage to the DB (and back again).

I will upgrade the inverter in the near future, so will 'oversize' the cables for this installation.

Can anyone tell me what I need ?
Perhaps I get those cables for him so that he can get going .

 

Very tricky question ....

 

1. You need to be very clear on your immediate, and possibly longer term, split of your DB ....  THIS will determine the "maximum load".  ... well, sort off ....

 

2. What is the kW rating of this "small inverter" ?  Possibly more important, what is the kW rating of your "later upgrade", as THIS is actually the "maximum load" to size the cable for future use.

 

 

 

1 & 2 .... if your DB split results in a potentially higher load than the inverter capacity then you need to get back to the drawing board ....

 

 

3. IF you can get cables that your sparkie cant get ..... GET A NEW SPARKIE !!  Decent sparkies have a network of suppliers.  Your chances of sourcing the cable, and getting it at a better price is very unlikely .....

 

 

 

 

Link to comment
Share on other sites

2 minutes ago, Pure Savage said:

I know they used flat but thick cables on ours, 2 only just fit in a 25mm pipe.

 

From my install I think it was this:

image.png.d1437b25ede219fd22c2dd652aacc3f2.png

 

This is a very common size used for PV installations .... so they have rolls of this, and often use this where 4mm might have done the job.  Especially since the internal installation normally is short runs only.

Link to comment
Share on other sites

As already mentioned, the cables required depend on your load requirements.

You will also need various protection breakers, and a change over switch.

Also, is the cable run inside the garage, or does it go outside at any point? This will also affect the type of cable required.

Link to comment
Share on other sites

30 minutes ago, Schnavel said:

As already mentioned, the cables required depend on your load requirements.

You will also need various protection breakers, and a change over switch.

Also, is the cable run inside the garage, or does it go outside at any point? This will also affect the type of cable required.

Yeah, our system is a 5kw, so thought these should be fine for him.

Link to comment
Share on other sites

A question, my sister in law may be moving in next door. would it be possible to connect the inverter to a 3rd DB board?

Just to power like lights and a plug circuit or two, depending on how many times we get invited over for braais.

Link to comment
Share on other sites

51 minutes ago, Pure Savage said:

A question, my sister in law may be moving in next door. would it be possible to connect the inverter to a 3rd DB board?

Just to power like lights and a plug circuit or two, depending on how many times we get invited over for braais.

Just gooi an extension lead over the wall.

Not joking, a have a friend who does that for his neighbour...

Link to comment
Share on other sites

2 hours ago, ChrisF said:

Very tricky question ....

1. You need to be very clear on your immediate, and possibly longer term, split of your DB ....  THIS will determine the "maximum load".  ... well, sort off ....

2. What is the kW rating of this "small inverter" ?  Possibly more important, what is the kW rating of your "later upgrade", as THIS is actually the "maximum load" to size the cable for future use.

1 & 2 .... if your DB split results in a potentially higher load than the inverter capacity then you need to get back to the drawing board ....

3. IF you can get cables that your sparkie cant get ..... GET A NEW SPARKIE !!  Decent sparkies have a network of suppliers.  Your chances of sourcing the cable, and getting it at a better price is very unlikely .....

I thought my question was 'How long is a piece of string?' 

I am not looking for a better price, just availability
Except that I don't know what I am looking for 🤣
He said something about armour cable at R 150/m.
And it would be for internal use only.

I currently have a 3kVa inverter and hope to get a 5 or maybe even an 8kVa later in the year. That plan was to get cables with that in mind.

Breakers and Change Overs are all part of the package - it just seems that the cable is in short supply.
I had better press him for more information and possibly a bit more effort...

Next silly question:
Are all houses 3 phase ?
So, would that affect the type of inverter I would get ?

Edited by splat
Link to comment
Share on other sites

1 hour ago, splat said:

I thought my question was 'How long is a piece of string?' 

I am not looking for a better price, just availability
Except that I don't know what I am looking for 🤣
He said something about armour cable at R 150/m.
And it would be for internal use only.

I currently have a 3kVa inverter and hope to get a 5 or maybe even an 8kVa later in the year. That plan was to get cables with that in mind.

Breakers and Change Overs are all part of the package - it just seems that the cable is in short supply.
I had better press him for more information and possibly a bit more effort...

Next silly question:
Are all houses 3 phase ?
So, would that affect the type of inverter I would get ?

 

8kVA  .... now you are getting to about 37A 220V.  By rule of thumb, a 4mm wire is getting borderline.  Doing the actual calcs (volt drop over distance, and heat dissapation, etc) it could be a 6mm wire, or even bigger if the installation needs it.

 

Armoured cable .... sounds like some of the cable wont be in sleeves ..... and yes, these cables are going to be more expensive.

 

Well worth the effort to get a second sparkie in the area to give you a quote - after seeing the actual site limitations.

 

 

NO, very few homes are 3 phase.  At least very few modern "normal" homes.  Older homes were often 3 phase, now it is just the very large homes that are still built with 3 phase.

 

Your sparkie can look at YOUR use, and advise if it makes sense to switch to single phase.....

 

YES, 3-phase means a totally different PV install ! 

 

 

You need to have a drink with your solar guy to take you through the options and costs .... then chat to your sparkie about the costs, and practicalities, of switching to single phase ....  Maybe you have some three phase pumps and cant switch, possibly it is just a historical thing and you dont need it .....

Link to comment
Share on other sites

On 1/26/2023 at 5:08 PM, Pure Savage said:

Have found with this process the devil is in the detail - like the pump for the solar geyser is 12v with its only little panel - cute. But the geyser wise is on the geyser breaker, so when load shedding the pump stops and does not circulate and is not as efficient. 

Thinking of running a separate cable from a plug circuit to power the geyser wise, so the 12v pump can work during load shedding.

I have a similar but different problem:

  • 3kVA Inverter powers, lights, TV, internet etc. (Nothing in the kitchen, workshop or other appliances).
  • Solar hot water with tandem geysers - works well.
  • Electric element in geyser on utility power.
  • 220V circulation pump on geyser on utility power.
  • Geyserwise controllers on utility power.

Now I want the circulation pump to run off the inverter but the geyser elements must stay on utility. Obviously some relays required. Has anybody got a solution to this?

Link to comment
Share on other sites

16 hours ago, Pure Savage said:

A question, my sister in law may be moving in next door. would it be possible to connect the inverter to a 3rd DB board?

Just to power like lights and a plug circuit or two, depending on how many times we get invited over for braais.

We have in essence 4 DB's on our system. 1 in the kragstasie shed. From there the power goes to a DB in the garage/office building. From there the house and the cottage are fed. Just add a breaker switch in your db and feed from yours to the neighbour. They will need a full on changeover switch though and a split DB.

15 hours ago, splat said:

I thought my question was 'How long is a piece of string?' 

I am not looking for a better price, just availability
Except that I don't know what I am looking for 🤣
He said something about armour cable at R 150/m.
And it would be for internal use only.

I currently have a 3kVa inverter and hope to get a 5 or maybe even an 8kVa later in the year. That plan was to get cables with that in mind.

Breakers and Change Overs are all part of the package - it just seems that the cable is in short supply.
I had better press him for more information and possibly a bit more effort...

Next silly question:
Are all houses 3 phase ?
So, would that affect the type of inverter I would get ?

Most farm houses are 3 phase because a lot of the older borehole pumps were 3 phases and when you are getting from eskom direct they usually supply 3 phase to farms. But remember pretty much every major suburb was a farm so in most suburbs there is an orginial farm house which is usually old and often still on 3 phase. It is really not a big one to sort though. Usually they will split it that each phase runs a different system as a single phase system except for the odd 3 phase thing. We had lights on 1 phase, plugs on another phase and then stove/fridges on the third phase. But it was all single phase stuff so the DB just needed to be rewired. We took out the 3phase borehole pump and put a nice small single phase one in. I miss the 3 phase plug for running a bigger welder that is literally it, and the inverter welder is more pleasant to use anyway. Still saving for a petrol welder.

13 hours ago, ChrisF said:

 

8kVA  .... now you are getting to about 37A 220V.  By rule of thumb, a 4mm wire is getting borderline.  Doing the actual calcs (volt drop over distance, and heat dissapation, etc) it could be a 6mm wire, or even bigger if the installation needs it.

 

Armoured cable .... sounds like some of the cable wont be in sleeves ..... and yes, these cables are going to be more expensive.

 

Well worth the effort to get a second sparkie in the area to give you a quote - after seeing the actual site limitations.

 

 

NO, very few homes are 3 phase.  At least very few modern "normal" homes.  Older homes were often 3 phase, now it is just the very large homes that are still built with 3 phase.

 

Your sparkie can look at YOUR use, and advise if it makes sense to switch to single phase.....

 

YES, 3-phase means a totally different PV install ! 

 

 

You need to have a drink with your solar guy to take you through the options and costs .... then chat to your sparkie about the costs, and practicalities, of switching to single phase ....  Maybe you have some three phase pumps and cant switch, possibly it is just a historical thing and you dont need it .....

Interestingly though, 3 phase invertors are really not badly priced and you usually get a much bigger inverter. There is a 12kw 3 phase blue mountain which is only 10k more expensive than an 8kw deye. I have also seen it where 3 single phase inverters are used in parallel as 3 phase.

I have been doing the math on seeing if I can get our dairy 100% off grid. The bigger you go the R/kw and R/kwh drops and the 3 phase stuff is often more readily available. I looked at it the other day and to have a big 3 phase inverter and a monster battery and major panels but have it shared between 3 houses(each with a phase) would actually work out cheaper.

re the cable- 32mm low grade hdpe pipe over the armored cable is a good idea. You can use it as a conduit so you can pull extra cables through easily and keep them waterproof if running underground. The lower grades are also dirt cheap. We run all our longer armored cables through them just for extra protection- the one borehole which has a 2,75kw pump is about 300m out in a field that has heavy cow traffic. Small plastic bag tied to a roll of bailing twine and then you just use a vacuum cleaner to pull the bag through leaving the twine as a draw wire. Then the bailing twine to pull the cable through.

Link to comment
Share on other sites

16 minutes ago, dave303e said:

We have in essence 4 DB's on our system. 1 in the kragstasie shed. From there the power goes to a DB in the garage/office building. From there the house and the cottage are fed. Just add a breaker switch in your db and feed from yours to the neighbour. They will need a full on changeover switch though and a split DB.

Most farm houses are 3 phase because a lot of the older borehole pumps were 3 phases and when you are getting from eskom direct they usually supply 3 phase to farms. But remember pretty much every major suburb was a farm so in most suburbs there is an orginial farm house which is usually old and often still on 3 phase. It is really not a big one to sort though. Usually they will split it that each phase runs a different system as a single phase system except for the odd 3 phase thing. We had lights on 1 phase, plugs on another phase and then stove/fridges on the third phase. But it was all single phase stuff so the DB just needed to be rewired. We took out the 3phase borehole pump and put a nice small single phase one in. I miss the 3 phase plug for running a bigger welder that is literally it, and the inverter welder is more pleasant to use anyway. Still saving for a petrol welder.

Interestingly though, 3 phase invertors are really not badly priced and you usually get a much bigger inverter. There is a 12kw 3 phase blue mountain which is only 10k more expensive than an 8kw deye. I have also seen it where 3 single phase inverters are used in parallel as 3 phase.

I have been doing the math on seeing if I can get our dairy 100% off grid. The bigger you go the R/kw and R/kwh drops and the 3 phase stuff is often more readily available. I looked at it the other day and to have a big 3 phase inverter and a monster battery and major panels but have it shared between 3 houses(each with a phase) would actually work out cheaper.

re the cable- 32mm low grade hdpe pipe over the armored cable is a good idea. You can use it as a conduit so you can pull extra cables through easily and keep them waterproof if running underground. The lower grades are also dirt cheap. We run all our longer armored cables through them just for extra protection- the one borehole which has a 2,75kw pump is about 300m out in a field that has heavy cow traffic. Small plastic bag tied to a roll of bailing twine and then you just use a vacuum cleaner to pull the bag through leaving the twine as a draw wire. Then the bailing twine to pull the cable through.

I sommer feel like taking a leave day at work today to go and test that bailing twine vacuum bag move. Sounds like a brilliant idea. 

Link to comment
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
Settings My Forum Content My Followed Content Forum Settings Ad Messages My Ads My Favourites My Saved Alerts My Pay Deals Help Logout