Is home UPS worth it?

[LaraC]

Hi everyone,

I’ve seen a 6.0 KVa – 48Volts True Sine Wave Home UPS System at http://gwstore.co.za/product/home-ups/# which sells for R20340.

According to the website it is designed for continuous operation, installs directly into your DB and it has a built-in 5-stage 30Amp charger.

I would appreciate it if you could give your opinion regarding price vs. features?

Thank you.

 

[henry1103]

You will also need quite a good amount of batteries.

 

[greg_SA]

I assume this is for load shedding? Well, it really depends on how much value you attach to "keeping the lights on"

For me, I went around ins circles, planning small systems to large ones that I could upgrade to solar, grid-tie, etc, etc... but my wife convinced my in the end to actually get something that would solve the actual frustration of load shedding...

For me, I just want to keep the lights on, continuously, and keep all security (alarm) running. Then being able to keep my home server running and Wifi router, etc is a bonus, as well as to be able to use the TV and DSTV.

All that together, we only need a 1kW inverter. It is purely for load shedding - I don't care about solar - I don't plan to invest in that for another few years.

So a 1kW proper home UPS, with 2 x 100Ah batteries will cost about R10k. I needed to replace my camping batteries anyway, so my cost was even less. You'll have to add the cost for an electrician if you can't do it yourself (you'll need to get a COC anyway).

It is wired to the DB, and feeds everything (as mentioned above) continuously - no switching anything. So when the power is cut, the only thing I can't do is cook in the electric oven (just use gas hob), or use the dishwasher and other high power items, which I don't have to use anyway. Our evening routine is hardly affected.

So for me, a sub R10k UPS is worth it... but a 5kVA system with solar panels, large battery banks, etc grid tie of R50k+ is not worth it for me...

 

[LaraC]

Thank you greg_SA.

Yes, it would be used for blackouts. I’ve taken note of your recommendation to spend minimal and only tie in circuits which I would like powered.

 

[The_Traveller]

Thank you greg_SA.

Yes, it would be used for blackouts. I’ve taken note of your recommendation to spend minimal and only tie in circuits which I would like powered.

You can get a 6kw 24/48v system for around R15k ( most likely less) . I set up for my cousin a 5kw system with 8 x 150ah batteries about a month ago.
Not sure what backup time you require but R15k + batteries + electrician cost . If you live in GP , I know of an electrician who is a master and charges next to nothing. If you interested can always PM me..

 

[savage]

You can get a 6kw 24/48v system for around R15k ( most likely less) . I set up for my cousin a 5kw system with 8 x 150ah batteries about a month ago.

6KW of power on 150Ah? There is no way in HELL that will last even remotely close to a hour under that load. 150Ah will MAYBE run 600W (not 6KW) for a hour, maybe two....

There is no magical system here. It all comes down to what your ACTUAL load is (not the size of your inverter), vs. for how long you want to run your load. If you increase your load (irrespective of the inverter), your battery WILL drain faster. If you drain your battery more than 50% the lifetime of that battery WILL be reduced.

 

[The_Traveller]

6KW of power on 150Ah? There is no way in HELL that will last even remotely close to a hour under that load. 150Ah will MAYBE run 600W (not 6KW) for a hour, maybe two....

There is no magical system here. It all comes down to what your ACTUAL load is (not the size of your inverter), vs. for how long you want to run your load. If you increase your load (irrespective of the inverter), your battery WILL drain faster. If you drain your battery more than 50% the lifetime of that battery WILL be reduced.

calm down savage !

Who said Peak power was 6kw ?

who said the 5kw system was also loaded with 5kw of peak power ? the 5kw system is a 48v so has 4 x 150ah in series and another string of 4 x 150ah in parallel. Peak power is around 3kw but obviously when it load shedding time, they don't keep all 300 downlights on for fun.

 

[savage]

I am calm,

I just hate inaccurate posts, because now n00bs, expects us professionals to install 5KVA systems capable of running 4KW of power for 2 hours off batteries, for R15K - because 'he is doing it'

Then when we give them the quotes, then we are 'coining it big time' because the person is a uber n00b, not understanding his own requirements, but wants it for nothing...

Pisses me off, sorry...

 

[The_Traveller]

I am calm,

I just hate inaccurate posts, because now n00bs, expects us professionals to install 5KVA systems capable of running 4KW of power for 2 hours off batteries, for R15K - because 'he is doing it'

Then when we give them the quotes, then we are 'coining it big time' because the person is a uber n00b, not understanding his own requirements, but wants it for nothing...

Pisses me off, sorry...

That's the nature of business, but you already knew that.

 

[savage]

That's the nature of business, but you already knew that.

I know. Hence - need to set the record straight and keep expectations realistic as well

 

[LaraC]

You can get a 6kw 24/48v system for around R15k ( most likely less) . I set up for my cousin a 5kw system with 8 x 150ah batteries about a month ago.
Not sure what backup time you require but R15k + batteries + electrician cost . If you live in GP , I know of an electrician who is a master and charges next to nothing. If you interested can always PM me..

Unfortunately I'm in the Eastern Cape and I haven’t found that many places who sell inverters for comparison.
Ideally I would like to have backup power for at least six hours with minimal load on the system. The reason I thought of using a large inverter is for the convenience of having all plugs and lights connected.

 

[LaraC]

I know. Hence - need to set the record straight and keep expectations realistic as well

Would you recommend I speak to a professional without taking the time to obtain opinions and best practices from people who installed similar systems?

 

[Mr Feesh]

I assume this is for load shedding? Well, it really depends on how much value you attach to "keeping the lights on"

For me, I went around ins circles, planning small systems to large ones that I could upgrade to solar, grid-tie, etc, etc... but my wife convinced my in the end to actually get something that would solve the actual frustration of load shedding...

For me, I just want to keep the lights on, continuously, and keep all security (alarm) running. Then being able to keep my home server running and Wifi router, etc is a bonus, as well as to be able to use the TV and DSTV.

All that together, we only need a 1kW inverter. It is purely for load shedding - I don't care about solar - I don't plan to invest in that for another few years.

So a 1kW proper home UPS, with 2 x 100Ah batteries will cost about R10k. I needed to replace my camping batteries anyway, so my cost was even less. You'll have to add the cost for an electrician if you can't do it yourself (you'll need to get a COC anyway).

It is wired to the DB, and feeds everything (as mentioned above) continuously - no switching anything. So when the power is cut, the only thing I can't do is cook in the electric oven (just use gas hob), or use the dishwasher and other high power items, which I don't have to use anyway. Our evening routine is hardly affected.

So for me, a sub R10k UPS is worth it... but a 5kVA system with solar panels, large battery banks, etc grid tie of R50k+ is not worth it for me...

assuming the electrician will only make the ups "support" certain cables on the db board, ie I can choose to run 2 rooms and not another?

 

[midnightcaller]

I assume this is for load shedding? Well, it really depends on how much value you attach to "keeping the lights on"

For me, I went around ins circles, planning small systems to large ones that I could upgrade to solar, grid-tie, etc, etc... but my wife convinced my in the end to actually get something that would solve the actual frustration of load shedding...

For me, I just want to keep the lights on, continuously, and keep all security (alarm) running. Then being able to keep my home server running and Wifi router, etc is a bonus, as well as to be able to use the TV and DSTV.

All that together, we only need a 1kW inverter. It is purely for load shedding - I don't care about solar - I don't plan to invest in that for another few years.

So a 1kW proper home UPS, with 2 x 100Ah batteries will cost about R10k. I needed to replace my camping batteries anyway, so my cost was even less. You'll have to add the cost for an electrician if you can't do it yourself (you'll need to get a COC anyway).

It is wired to the DB, and feeds everything (as mentioned above) continuously - no switching anything. So when the power is cut, the only thing I can't do is cook in the electric oven (just use gas hob), or use the dishwasher and other high power items, which I don't have to use anyway. Our evening routine is hardly affected.

So for me, a sub R10k UPS is worth it... but a 5kVA system with solar panels, large battery banks, etc grid tie of R50k+ is not worth it for me...

Now this is thinking very smartly.

 

[greg_SA]

assuming the electrician will only make the ups "support" certain cables on the db board, ie I can choose to run 2 rooms and not another?

Yes, that is correct. You just run the essentials - lights, and specific plug circuits.

 

[The_Traveller]

Yes, that is correct. You just run the essentials - lights, and specific plug circuits.

The only problem with having a system connected directly to the db is that if a certain plug point ( or circuit for that matter) is backed up, and that specific inverter is an in-line one that provides the power whether there be Grid power or not, and you go and plug in a heater or high powered vacuum etc., then that inverter will shut off , shutting off everything connected to it.

Some inverters don't have bypass modes ...

 

[greg_SA]

The only problem with having a system connected directly to the db is that if a certain plug point ( or circuit for that matter) is backed up, and that specific inverter is an in-line one that provides the power whether there be Grid power or not, and you go and plug in a heater or high powered vacuum etc., then that inverter will shut off , shutting off everything connected to it.

Some inverters don't have bypass modes ...

Yes, that is true - I have blanked off the appropriate plug points with cover plates (as used to protect babies). They are labelled with a sticker that says UPS. So everyone in the house knows that they must not use those plugs. I have enough other plug circuits for high powered things - like vacuums.

Or if you have access to all the wiring, you can isolate specific plug sockets for the UPS. But I didn't have that option.

 

[LaraC]

Yes, that is correct. You just run the essentials - lights, and specific plug circuits.

Is there a maximum distance the inverter and batteries should be from the DB?

 

[greg_SA]

Is there a maximum distance the inverter and batteries should be from the DB?

Not really an issue.

For the 220V wiring any distance in a normal house should be fine. If it is really far, then you could increase the size of the wiring.

The same rules apply as do for a plug point. For eg. my DB is in the garage, and I have a plug point in a bedroom with wiring running about 20m.

The general rule of thumb is 1.5mm wire for 10A, 2.5mm wire for 20A, 4mm for 32A, etc.

 

[LaraC]

Not really an issue.

For the 220V wiring any distance in a normal house should be fine. If it is really far, then you could increase the size of the wiring.

The same rules apply as do for a plug point. For eg. my DB is in the garage, and I have a plug point in a bedroom with wiring running about 20m.

The general rule of thumb is 1.5mm wire for 10A, 2.5mm wire for 20A, 4mm for 32A, etc.

Awesome! I was worried that it should be in close proximity of each other.