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Thread: GENERATORS?UPS?INVERTERS?

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    GENERATORS?UPS?INVERTERS?

    Does anyone on the forum have any info or experience with any of the above?
    I would like to know what other businesses are using or what they are looking at.
    Any pro's and con's I should know about.
    As I understand it a ups will last or only a few minutes but I am told with new technology they can last for days and are better than generating power all the time.......any advice please

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    just me duncan drennan's Avatar
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    What exactly do you want to power?
    [SIGPIC]Engineer Simplicity[/SIGPIC]
    Turn ideas into products | The Art of Engineering blog

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    Site Caretaker Dave A's Avatar
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    If it's computers, even if you go with a generator, you're going to need a UPS with inverter to control the supply anyway. As for how long a UPS can keep you up for - well that depends on the load and the storage capacity of your batteries.
    The trouble with opportunity is it normally comes dressed up as work.

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    It order to keep a whole office running with all the desktop workstations will mean that the UPS will require its own power circuit routed to all work stations. If you are located in Gauteng. This may be worth while as it will also lessen damage caused by lighting strikes. Maybe cover the switchboard as well.

    However the UPS will have to be huge to power the system for an extended period of time.

    Normally I used a UPS (a UPS has a built in invertor and batteries) which was linked to the servers, so that it would keep the servers going, while they initiated an automatic shut down, This occurred within 20 minutes. So 20 minutes to a hour I would say.

    If you want to protect workstations from data loss and remain up and running for longer than that, then the UPS can be powered from a generator The size of the generator and the UPS will depend on the total KW's that all the equipment in the server room, all the workstations, and switchboard need.

    When we started having the power outages in Cape Town, I arranged a temporary situation with a generator (an industrial generator/welder, they may be cheaper per KW and may have a better resale value) and a network of extension leads to reach the workstations. ('n Boer maak a plan) This was only used once

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    Email problem apropos's Avatar
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    Professional Help Available

    I can recommend PSS Distributors to help you with all your UPS and back-up power needs.

    They provide good quality products at reasonable prices, with advise, service and maintenance staff available on your doorstep.

    See this link to calculate your needs:
    http://www.powersystems.co.za/configurator.php

    or contact Wayne Woolley at
    Johannesburg Branch
    P.S.S. Distributors c.c.
    P.O. Box 4113, Edenvale, 1610
    5 Diagonal Rd, Eastleigh, Edenvale
    Telephone: (+2711) 452-4059
    Facsimile: (+2711) 452-4088
    e-mail: sales@powersystems.co.za

    I know they would be glad to help!
    Regards
    Genevieve

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    here are some tips:

    firstly you can use a ups or an invertor with a whole lot of batteries to provide power to your home or office...it is a quieter but more expensive option...and when the batteries go flat you need power/generator to charge the batteries...some people dont have a choice because they live in flats so a generator is not an option...be carefull with batteries not to short them out...and remeber they are full of acid...make sure they are sealed and enclosed properly...and kept away from children.

    i always advise my customers to use an online UPS to protect their computors...servers...and any sensitive electronic equipment (the one which has built in surge protection)... regardless of load shedding or not...connected directly to all the red or dedicated plugs.

    i have one customer where i installed a big unit to run the entire office more than 10 years ago...they were having problems loosing data so i connected a big online unit it cost a lot of money but still to this day the UPS is running and they have had no problems with data loss due to dips and swells or surges in the electricity supply saving them lots of money in data loss and computor replacements

    now with the load shedding you need to make sure that the UPS has a frequency tolerance of at least 45 to 55 hz if you want to run the UPS from a generator...and then you will ask why...well the cheaper generators have the buzz word at the moment "AVR automatic voltage regulation"...you do need voltage regulation but the problem is with the frequency which can go as high as 54/55hz when the generator is not under load...and some of them drop as low as 46 hz...if the UPS is old or not designed to with a high torence then it will just keep switching off line...

    buy a couple of small 2 tube fluoresnt light fittings and switch it to 1 tube and you should get 3 -6 hours...dont buy the osram green camping light they are a waste of money the batteries dont last...and make sure the light has a charger which will not over charge if left on charge...electric world has a good light for around R115 on special.

    whatever you do dont plug to plug your generator in your house...it is extremely dangerous it overides all the safety devices in the distribution and can cause a dangerous enviroment for electricians working on the lines..the cheapest most pratical way to do it is to fit a manual changeover switch with an ammeter to determine how much power you have available...lets say you fit a 5 kva which is the most common one for your house...if you have a annalog ammeter you can run the tv fridge etc...then if you need to run the pool pump and the kettle for example you switch off some of the appliance then switch on others watching the ammeter needle when it reachs the limit marked with a marker pen on the ammeter you stop...just remember resistive loads like the kettle...geyser...toaster are have consistant loads but fridges...pool pumps...have start up currents which you need to allow for... so dont let the needle sit on the line...allow 5-10 amps for start up or if you hear the generator battling reduce the load by switching off more appliances.
    be even more careful with the positioning of the generator it will kill you slowly without you even knowing if the fumes get into the house...so whatever you do dont run the generator in a garage or next to a window...preferably get someone to extend the exhaust just above the roof height...heat will rise.

    also be careful of generator installers...every one and their uncles are installing generators now like aircons...there are a lot of fly by nights making a quick buck...make sure the installer is registered or you will have safety problem...there are no regulations for generators yet only guide lines...but the cable selection and changeover panel and labelling need to be up to spec...warning the electrician that there is a generator connected to the DB.

    you should be sorted if you have the following items at home:

    a solar heated geyser
    a gas hob
    battery emergency lights positioned correctly...connected directly to the mains/generator with a switch for when you go to bed
    an online ups or 2 with surge protection for sensitive electronic equipment and alarm connected to the mains/generator...
    and if you can fit an additional battery for your gate motor
    a 5 kva generator preferably diesel more expensive but should last longer and be more stable (i havent had a chance to test a diesel one yet for voltage and frequency stability) with an analog ammeter and a volt meter.

    or if you have R80000.00 we can just fit a big unit and it will switch on automatically when the power goes off will run the house as if there was never an outage...just fill the diesel...and for a small fee we will service the unit at the correct intervals as per the running hour meter.

    if you have a small office:

    have a load assesment done...to determine the size of the ups required and the amount of batteries neede to keep the office running for the load shedding period of 2/3 hours or a generator to keep the ups batteries charged and so that you dont loose data...it is not advisable to run a generator directly connected to your computer

    an oline surge protected ups with your computor...telephone...server...small printers connected..."not big printers" to keep the office running without any disturbances...an online is is more expensive but if you dont want to loose data it is a better choice especially for critical aplications.

    fit emergency lights with at least 6 hours backup time and over charge protection


    big companies

    get a company to do a load assesment (recording over a period of time not less than 8 hours/1 day)which will give you a good idea of the power consumption and give you professional advice on ways to keep you up and running.

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    PREPARE FOR WINTER or its gona be a cold one if you dont prepare...dont say you werent warned

    remember the oil...element heaters...electric blankets...aircon heaters.

    remember it stays dark later in the morning and gets dark earlier in the evening.

    and it takes more hot water to heat up the bath.

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    Site Caretaker Dave A's Avatar
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    Quote Originally Posted by murdock View Post
    also be careful of generator installers...every one and their uncles are installing generators now like aircons...
    Bottom line - Insist on an electrical Certificate of Compliance for the installation.
    The trouble with opportunity is it normally comes dressed up as work.

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    Thanks for the info Murdock
    Regards

    Debbie
    debbie@stafftraining.co.za

    From reception to management training, assertiveness, accountability or interviewing skills, we have a wide range of training workshops available for you!
    www.stafftraining.co.za

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    i am busy quoting to install a 1 megawatt generator ooouuuch.

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