And the lights go out again.

[duncan drennan]

The exact requirements will depend a bit on your specific PC's and their uses....but this is what I would guess...

3x PC @ 200W = 600W (depending on usage/configuration this could range anywhere from 150W - 500W)
1x inkjet printer @ 50W
2x notebooks @ 90W = 180W
3x monitors @ 50W = 150W (for LCD's, about 150W/CRT)

So that totals 980W. Build in some extra, and I would guess you need about 1.5 - 2kW to be safe and happy. 1kW will be a bit on the edge (make sure the wattage is enough, as they often advertise the kVA's).

What I do is run everything off a UPS, and then if the power goes off, unplug the UPS and then plug the ups into the generator (that way you also won't have any surprises when the power comes back on). When it comes back on just move it back to the mains.

Watch out for generators, they can have very unstable outputs (depends on the model/price), which is one of the reasons I prefer to run through a UPS, which will make sure the power the PC's see is stable.

[Chatmaster]

Well we just had our 3rd outage for the day...
Duncan how much are we talking about for a UPS and a 2kw generator. These guys are going to see me a mile of and I do not want to pay more than it is worth.

[Dave A]

5 kVA should handle that and a fair bit besides. It's kinda a handy size.

I once bought a 2.2 kVA petrol generator - it's very frustrating because it's too sensitive to load.

Go diesel if you can. They're a little more stable running.

[Chatmaster]

Well, I did some research on the UPS's. Man am I completely lost. I have no idea what any of the descriptions mean. Exactly how long can a UPS last and what should I look for?

[Dave A]

If you've got a generator - as long as it takes for you to switch over

I'm going to be running around doing some investigation on the subject myself tomorrow. I'll post what I find. Things are clearly going to get worse before they get better.

I've also set up a category for electrical load shedding information websites in the links manager. I've loaded the ones I've found so far. Add any you might find along the way too.

No luck for Joburg so far

[murdock]

all i can say is thank goodness i live were i do...we are not affected by load shedding yet....and thumbs up for the old goverment...thank you for building such a good power grid that it has this long...i dont know what we a going to do in the future... news today....they dont know if the budget is going to allow for the power stations because of the falling rand????? zimbabwe her ewe come.

anyone looking for a standby generator email me on:

electricalpowersolutions@gmail.com

some ideas

get small battery backup light fittings which last at least 3 hours which is connected directly to the power so that you dont get caught with flat batteries...
ups to run home computor tv and sensitive electronic equipment (because these cheap generators will destroy your equipment in time...even with AVR...
solar powered geyser...gas stove even a portable one just to heat water cook eggs etc you dont need an oven..use the microwave or buy a gas webber and of course dont forget to fill the gas bottles.
and a small generator to keep the ups charged run your fridge and deep freeze...which is not nessary if you dont keep opening the doors...keep frozen 2 lt bottes in the deep freeze and put in the fridge if an when required....

load shedding is a reality start planning your life around it...or keep getting caught in the dark...the light at the end of the tunnel is dimming...generator companies are making millions.

[duncan drennan]

Duncan how much are we talking about for a UPS and a 2kw generator. These guys are going to see me a mile of and I do not want to pay more than it is worth.

I'm really not too sure. I would shop around a bit, and see what is out there. Prices seem to vary dramatically. Try contacting Bundu Power, and see what they can offer you.

Here is Makro's price list for generators.

[duncan drennan]

load shedding is a reality start planning your life around it...or keep getting caught in the dark...the light at the end of the tunnel is dimming...generator companies are making millions.

That is the truth! The key issue here is to figure out how we can each make some small but significant changes which will have a lasting impact. Obviously the benefit for businesses of changing to lower power technologies, or saving energy where they can would be felt by all.

For example, just making sure that your computers are set to run on the lowest power possible will make a difference.

Some tips for computers:

1. Turn your screen saver off, and rather set your monitor to power down after 10-15 minutes of non use.
2. Set your computer's power management to "Minimal power mangement" (you will maintain performance, but when the cpu is not busy it will go into a lower power state). Here is how to manage power on Windows Vista.
3. Set your computer to sleep and/or hibernate after some period (then you can save power while not at your desk.
4. Choose a computer from the Climate Savers Computing product list.
5. Use a laptop if possible (they are generally a lower power option, but it depends on your needs).

By making the power management, screen off, sleep and hibernate changes to all the computers in your organisation you can make a significant savings in power. If all organisations do it the effect would be noticeable.

So ask yourself, "How many PCs are sitting idling for most of the day wasting electricity in my building?" Then take 10 minutes out of your day to fix it.

[Dave A]

We got load shed from 2-4pm yesterday and 8-10am today. The economics of putting in backup power generation is now officially beyond dispute for us.

I've just come back from Makro. They've got a 5.5 kVA petrol generator at R5 999.00 and a really sweet 6 kVA diesel for R12 000.00 - both have automatic voltage regulation (AVR) so they should provide a fairly clean electrical supply.

The 6kVA diesel looks identical to the 5kVA diesel shown on the Bundu Power website in case anyone is in the mood for comparative shopping. I don't have the patience for that kind of messing around right now. I need my solution in now - or at least by the next load shedding scheduled for our area tomorrow afternoon.

You might want to move fairly quickly. Makro Springfield alone sold R400 000.00 in generators yesterday.

I haven't got to checking out the UPS situation yet. Once I've tested the quality of the supply off the generator I'll know whether we really need one (or more). I might just get a UPS for our server anyway.

[Chatmaster]

I gave Bundu power a call. It looks like I will be going for the 2600 petrol model. Because I do workshops I will need to have something that fits in my car. I certainly cannot have a power failure while doing a workshop,lol They go for R4950. I think that is worth the price. I also decided that instead of buying a UPS I will rather upgrade my Notebooks and use it full time. My daughter Just scored a AMD 64 Athlon, lol

[Dave A]

We've been sourcing a cross-over switch at the moment.

Just a warning for the do-it-yourself types that comes from one conversation today - Do not connect your generator into your exsisting installation - When the power comes back on - one fried generator.

And I know some bright spark is going to say - "But if I switch off the mains isolator?"
You need an interlocked cross-over switch to make sure there is absolutely no way the mains power can reach the generator. Period.

It takes proper equipment and some planning to hook a generator into your existing electrical installation. For goodness sake, if that is what you want, get it done by an electrician!

[Chatmaster]

Well despite the Eskom website stating we will have no power cuts today, the power went off as I closed their website. It resulted into me spending R4500 on a portable Ryobi 650w and a Ryobi 2700 from Mica. Tomorrow I will be prepared and hopefully back in business.

[duncan drennan]

A question here for the electricians....

Generators have a ground terminal, does that have to be connected to a reasonable ground for safety purposes? If so, what is the best way to do this? What could happen if it is not connected?

[murdock]

from my experience dealing with power issues...my first choice would be an online UPS for all sensitive electronic equipment then a generator to run the UPS.

the connection you are talking about is promoted at places like makro i was listening to the fella selling generators at makro explaining to someone how to connect plug to plug...we call it a suicide cord because if you forget to switch off your main switch you could kill an electrician working on the line...depending on the impedance of the generator it might not blow up when the power comes back on it might just catch on fire...just remeber there is no circuit protection for you or your family if you connect it this way.

you need to connect the generator earth to the generator neutral as close to the generator as possible...and some people advise to put an earth spike just because it would be the closest route to ground...but there are a lot of debates going on about this...bottom line there are no regulations for generators at the moment only guidelines.

[Dave A]

Surely the mains supply earth is not being isolated in the power-down?

If we stick to the main earth safety strategy (no floating earths), I'd expect the best thing would be to connect the generator's earth to the main supply earth. Bridge neutral and earth at or near the generator if it isn't bridged in the generator circuitry already and mission accomplished.

Something else for me to bug my guys about tomorrow morning
They're the ones who have been doing our backup generator installs.