Electricity Generator(s): advice & help selecting

There are a few points people should watch out for when purchasing a generator:
1. Ask if the rating is at sea level or altitude. You should derate the gen output by 10-15% for Highveld conditions
2. Ask if the noise level in dB is at full-load or no-load (idle). The following dB values can be used as a guide
60 - Conversational speech
70- Business office
80 - Noisy traffic corner
90 - Heavy truck
100 - Very loud classical music
3. Also note that even on very high-end 3000rpm petrol gens (less than 6kVA), expected life is maximum 2000 hours (with proper maintenance). I have seen expected life values of 500-1000 hrs for low cost petrol gens. I would probably be cheaper to replace the gen than to have it fixed. Diesel 3000rpm should get between 2000-5000 hours before a major overhaul. 1500rpm diesel should get at 10000hrs before a major overhaul. It should be noted that the 3000prm are specified for emergency power and not standby or continuous power applications

I think there are sales people out there who are not informing the public correctly of their purchases and this could cost people in the long run. I have some units being sold with 2-4 month warrantees. The best thing is make sure of the guarantee/warrantee conditions (make sure it 1 or even 2 years), check the exclusions (running a stove etc) and make sure that spare parts etc are available
 
Thanks for the info. How many kWh can you generally expect per liter of fuel?
 
If my calculations are correct...

Prices from http://www.dme.gov.za/energy/breakdown03.stm
PETROL
02 January 733.00 c/l (93 ULP) and (LRP) Inland region
02 January 747.00 c/l (95 ULP) Inland region
02 January 719.00 c/l (93 ULP) Coastal region
02 January 723.00 c/l (95 ULP) and ( LRP) Coastal region
DIESEL
02 January 725.30 c/l 0.05% Inland region
02 January 728.70 c/l 0.005% Inland region



IG2600
@ Gauteng LRP prices: 733c per liter
3,3kW x 5 hours using 4,6 litres of petrol
0,489kWh per rand
R2,05 per kWh


KDE6700TA
@ 729c per liter
5,7kW x 9,5 hours using 16 litres of diesel
0,4642 kWh per rand
R2,154 per kWh

Are diesel generators generally less expensive? (because here it seems not to be the case...)

For an apartment, I currently plan to buy 1-3 100Ah deep cycle batteries, 1-3 1000Watt pure sine wave inverters, and a generator made by Kipor, Honda, etc. I want to run a bunch of energy saving bulbs, a small UPS (ie. it probably won't run off the generator), a kettle, and a fridge and microwave if Eskom is offline for too long. I'm not holding my thumbs for things to remain as they are through the Winter.

(My apartment lease is for one year, so I can't install anything permanently)
 
@bison
If u factor in the long term maintenance costs etc, then the diesel should come out cheaper. Upfront costs for diesel will be higher but u need to factor that into 3-5 year running costs using petrol. If u are going to run it for less than 3 years, then petrol should come out cheaper.

I am also looking at deep cycle batteries with a 2.5kVA inverter. The issue I have is that the batteries have a max 3 year life so I need to do the life cycle costing for a 2.5kVA inverter + 4 x 105 Ah batteries versus petrol/diesel. 105Ah batteries are approx 1k a pop. I have to weigh this cost up + kWh for charging the batteries versus buying a new petrol after 3 years. Pretty complex if u look at the long term effects but this is exactly what motor manufacturers do when selling car warranties and motor plans. The problem we have is that we do not know the failure rates/maintenance costs of backup power systems. The major parameter is all these equations is how long the power outage will be. Shorter outage times will swing preference to inverter/batteries or petrol gennies whereas longer outage time will sway the decision towards a more permanent automatic solution with 1500rpm diesel. I just hope solar panel costs would come down is this would make it a more viable solution in the near future.

All said, a well researched scalable solution would cost u more upfront but would save you money in the long term. I would also venture that the evenings are bliss during power outages (very low background noise, spend time with kids playing 'old school' games which does not need power, reading by candlelight etc). Maybe we should be looking at solar/green alternatives which do not increase our carbon footprints as we are in this for at least 2-5 years (1 x 5kW petrol generator emits the same fumes as 5 x idling medium size petrol driven vehicles)

I will see if I can work on the costing spreadsheet for inverter batteries versus petrol versus diesel.
 
Because I can't know how badly Eskom will fail, I plan to run low-power items like energy saving lights from the battery (and perhaps others as necessary). Not sure about whether I should run items requiring 1kW+ on the batteries or gennie - how much longer will the batteries last if they are never used to their max amperage?
To make my energy usage as cheap as possible, I intend to charge the batteries with Eskom power when possible, and only charge them with the gennie when Eskom power is not available.

How much does the Eskom "subsidized" solar water heaters cost?
 
bison234;1474019 How much does the Eskom "subsidized" solar water heaters cost?[/QUOTE said:
R17 000 after subsidy for my home according to their site. I will probably build my own.
Click to expand...
 
We do Generators in Gauteng

Hi there we install the generators aswell,We do all kinds of gens from 2.5kva - 200kva wich is more than enough for construction companies.

Prices excellent
 
I have no experience with generators so need some advice please.

A client has purchased a generator as follows



LT7000EC Lutian Gasoline Generator
Engine: Electric Start (Battery Exluded)
Air-cooled, 4 stroke, OHV 25˚ tilt, level shaft, 1 cylinder
Fuel tank capacity: 17L
Continous operating time: 9 hours
Generator: A.C. frequency: 50Hz
Rated: 220 Volts
Max A.C. output: 6 500 VA
Rated A.C. Output: 6 000 VA
Size and Weight: 69.5 X 52.5 X 54.5 (CM: L X W X H)
82 KG


They want to run 6 pc's, printers and pabx off this.

Can do or can't do ?
 
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For home use I've opted to use solar electric gear without the solar panel. This way all I have to do is add a solar panel and a regulator to expand the system. Currently I charge off Eskom.

My kit consists of:
1 x 95 Ah deep cycle battery
1 x 200 W sine wave inverter
1 x intelligent battery charger

Advantages are:
1. no noise
2. no fuel
3. clean power
4. installed in my study
5. expand with solar panel for free electricity

With 200W I am limited somewhat, but I can run:
1. Laptop
2. ADSL router
3. TV
4. DSTV
5. CFL light

At full use I'll get around 2-3 hours and at a more moderate use 5 hours.

The inverter also does 400W in peak mode for 20 seconds or so (in case I need to use a drill or such).

You could of course use a cheap square wave inverter for a fraction of the cost but I want to give my electronics the best power I can give it ...

Have a look at http://www.solardome.co.za/
 
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Actually I know nothing about generators !

Can you run printers off them directly ?

Do you have to plug them in via a ups ?

Can one connect small hubs/switches/adsl routers directly?

Is there a good url which answers these questions or gives tables as to how many items you can connect to a 'x'VA generator ?

The neighbours are going to go crazy - are these things below the legal decibel limit for a residential area ?

Never thought a pc techie would need to know this stuff....
 
Assume all PC's are around 500W = 3000W

Switchboard circa 100W at most!

So well within available power. But most generators will not feed a UPS as the A/C is very much alternating! Anywhere from 40Hz to 65Hz and most UPS have a tantrum with this! Switching in and out at random!

So supply the kit directly and all should be OK but not via a UPS.
 
Thanks !

That means... when the power goes off, the ups attached allows one to shut down the pc's, then you have to unplug the ups before you start up the generator?

When the power is back on one needs to reconnect the ups in preperation for the next failure ? With 6 pc's that could become a mission - or am I missing something ?
 
I have a generator but ...

I purchased a generator a few days ago and have yet to start it up. The tiny manual that came with this thing is deficient to say the least, and seems to assume that newby owners of generators already possess knowledge about issues that I've never heard of. :o I'm really nervous that I'm going to make a mess of this and hoping to cover all the bases before I pull that thingy to start it up.

I have the generator, the UPS, the extension lead but I have been unable to have the following questions answered:

What type of oil should be mixed with the petrol? :confused: (I know it's not sun tan oil or baby oil) - I'm guessing this is something I can buy at the local filling station? What do I ask for?

I'm going to be parking my generator in the garden and using it to supply power to one PC and peripheral equipment. Do I need to use an arrestor rod (or some such name)? It is supposed to "earth" or "ground" this setup. If so, what is this and where can I get one?

Any advice from members would be gratefully appreciated.
 
Oil advice

If you have a 4 stroke engine your genny will be happy with a can of oil that can be purchased at any garage. Just ask for oil for a petrol engine - think it's 20w50.

I've used synthetic oil (5w50) in mine to help prolong the engine (and also maybe reduce engine noise from what I've read, albeit slightly)

If your genny is a 2 stroke you would need a oil/fuel combo mixture. The motorbike shops might be able to provide more info on that.

If you are connecting directly to your peripheral it would be a good idea to ground the genny - although I know of people running them fine without earthing. There should be a marking on it indicating the earth contact.

If you connect it to your home with a crossover switch fitted by an electrician, the grounding is taken care of.

Hope this helps.
 
Two Stroke Generator

Thank you for your help Mr M.
Yup, it is a two stroke, I will contact a motorbike shop in the morning. :cool:
 
Anyone know where to start looking for a UPS? Just a little cheap one - just need enough time to shut down a PC when the power goes down.

Would they stock these at places like Makro and Builder's Warehouse? Or is it better to look around online?
 
Setting up a generator is a costly exercise, the best would be to get a consultant in to give you a quote (Meissner does this) Some things I ran across in my searching:

1. Solar power is a poor alternative at the moment. To run you home completely on solar power (about 20 kVa) will cost over 150K, although you can phase it in over time (not helpful with the Eskom issues at the moment)

2. Try http://jetmansa.com/ for some prices on generators, although I'd say you'll need around 25kVa to keep your 60 pc's running (about 90K from jetman). I bought a 6Kva from them, their service and prices were good. Check www.fonet.co.za for a device that gives you the kva usage for each appliance (including peak) that you intend to put on the generator. Add them all up to work out your kVa needs.

3. To avoid a temporary loss of power, you'll need to back it up with a UPS which will carry the load for 30-60 seconds so that the generator can kick in. If you don't care about this, obviously it doesn't matter. To wire it to your DB board, you will need a crossover circuit which a decent electrician will be able to do.

4. Generator power costs about 5 times what you pay for it from Eskom

Basically, it's an expensive exercise, I would guess with the UPS, this would cost you about R150K-200K
 
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