UPS or quiet generator

[hellfire]

How about an inverter instead of a UPS or generator?

 

[DrJohnZoidberg]

Quality UPS systems don't come cheap . Expect to pay R8k+ for a 5kva UPS system that has functions that avoid battery damage.
I got a good one that automatically keeps the charge at optimum levels.

I was looking at 3kva UPS that were around 14k in price :/

We just bought a rackmount 1.5Kva 900W UPS for R6500. It's one thing I definitely wouldn't skimp on.

 

[BBSA]

http://www.popularmechanics.co.za/tech/sinetech-power-trolley-6-banish-dark/

http://www.skunk.co.za/battery_back_up.php

 

[The_Traveller]

How about an inverter instead of a UPS or generator?

UPS for me any day albeit they both work very similar. A UPS system won't shut down your backed up appliances whereas an Inverter will.

 

[The_Traveller]

We just bought a rackmount 1.5Kva 900W UPS for R6500. It's one thing I definitely wouldn't skimp on.

Please tell me you have ample battery power because R6.5k is really expensive. I paid R7k for my 5kva UPS (no batteries) about 18m ago.

 

[Drunkard #1]

Those bloated batteries result from a charger simply "pushing" a charging current towards the battery, without any feedback as to how the battery is absorbing the charge

Many batteries can develop an internal short (insulation breaking down) or open circuit (plate clamps coming loose) which will cause the battery to heat up and swell.

I have been using rechargeable batteries in my job since 1976 and have seen all manner of manifestations occur

Paradox (an alarm co based in Canada) have developed an intelligent charger which will stop the charge current and measure the state of the battery at regular intervals. It is suggested that each individual battery in a multiple battery system be equipped with such a charger as you can never know which battery will malfunction and when. It is quite easy with diodes to isolate each battery from the other.

I got a 3000VA UPS with "pure sine wave" output for someone last week. Despite costing R 4400 + VAT and having 6 x 12 volt 7.0 a/h batteries, all the batteries were connected in parallel without any isolation or protection. Yesterday I went to check on the batteries and found one getting quite warm. Instead of an open circuit voltage of 13,65 like the others, this one was down to 12,10 V. Of course the supplier maintains that they have never had any problems, but here is a new unit with the transformer blazing hot trying in vain to charge a faulty battery

So the argument of melted batteries above is a real and present danger and you must be prepared to inspect the batteries on a regular basis

Batteries where the insulation breaks down are often found to use cardboard as an insulator. Rough handling (even dropping) of the battery compromises the insulation, shortening the life

+1

APC also makes an individual battery monitor, but not even their R 100 000 UPS come with it as standard equipment. Ideally you should be running 2V flooded lead acid cells (96 of them in 16 batteries) with individual monitoring, but the cost is just too high for anything under 200Ah, and normal UPS battery charger circuitry won't handle even that much.

The sweet spot for me was to eliminate parallel strings, and run 16 x 42Ah 12V VRLA batteries. The current load shedding situation has forced me to re-assess - I'd now rather run a smaller UPS (3kVA), and have the entire DB on a truly silent AMF generator.

Quality UPS systems don't come cheap . Expect to pay R8k+ for a 5kva UPS system that has functions that avoid battery damage.
I got a good one that automatically keeps the charge at optimum levels.

Those batteries are from R 35 000 6kVA and R 33 000 5kVA systems. Even the cheapest UPS keeps the charge at optimum levels.

 

[Gnome]

I've so far been using APC UPS with 2x100Ah batteries. However APC UPS have really, really bad quality battery chargers.

It is essentially a dumb charger and really limits the life of the battery. Worse, if you use it with flooded cell batteries it is really dangerous because it releases hydrogen due to over charging.

I'm thinking my new setup will likely end up being this:
http://currentautomation.co.za/cotek/st1000-224

Cotek make some of the best inverters and that inverter has an automatic transfer switch. So when the power goes out, it switches to the inverter like a UPS does. The chargers will obviously be off at that point.

Then I'll make use of two of these: http://www.amazon.com/NOCO-G7200UK-...e=UTF8&qid=1418342532&sr=8-1&keywords=g7200uk

That charger is a very high quality smart charger. TThey can be connect 24/7/365 and maintain your battery for maximum life.

And I'm using the 24v model of the Inverter so I can go series with the batteries. The advantage of using batteries in series is that each battery can be managed by its own individual charger. I may consider going 48v and using 4 chargers but that gets pretty expensive.

My only real concern with this setup is the transfer time of the Cotek ST1000 which is rated as approx. 13ms. That is quite a bit longer than the APC Smart UPS 2-4ms transfer time. Not sure if all electronics would transfer without interruption.

Anyway, time will tell.