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Thread: VOV generators

  1. #1
    Full Member Tonye's Avatar
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    VOV generators

    I know this topic has been dealt with on numerous occasions but feel we need to make all aware of the regulations & dangers of connecting a VOV generator to an existing fixed electrical installation.

    As load shedding is again part of our daily lives, people are reverting to generators for backup power.
    Please be advised that most portable generators sold in SA are VOV wound and may not be connected to a fixed electrical installation.

    SANS 10142-1 states in clause 7.12.2.7 that a 230 V generator with a V-O-V earth connection (centre tap on winding which is earthed) shall
    not be connected to a fixed electrical installation. Such a generator may only be used as a free-standing unit to provide power to specific appliances
    Read more at
    http://www.prellexpower.co.za/index....er-regulations

    That been said, there are many companys connecting them with a change over switch to fixed installations.
    Should an incident occur, all involved parties will be investigated and the homeowner could attract liability if
    the installation is not safe or is not correctly used.
    It could also invalidate the insurance on the property.

    Note: Remember that any alternate power installation must be executed by a person registered with the DoL.
    The registered person must issue a CoC upon completion of the electrical installation.

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    AndyD (11-Dec-18)

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    Diamond Member AndyD's Avatar
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    I think part of the problem is that it's not easy for an end user/customer to identify the winding arrangement of a generator and they're often mis-sold as being suitable for home power back-up when they're not.

    As a rule of thumb any portable contractors type generator that comes with a steel tubular frame is not suitable for wiring to a DB.


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    Try tell the customer...like not being allowed to walk on a freeway...there are bus stops on the N2 and various other freeways/national highways...you are not going to stop it...somebody needs to come up with a solution...soon.

    The way to overcome this problem at the moment...you install the change over switch and fit a plug...it is not your problem what is connected to the plug.

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    Thank you for raising this topic. I have veered away from working with generators due to my ignorance on the subject. I am in a dark place with this subject and was hoping the thread may be revived and some clarity brought up around this subject.
    TIA

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    Load shedding stage 4 yesterday bought out all the genrators again ... they are everywhere ... on wheels ...at the SPar shop ... at the wholesaler ... at the neighbours ... 90 % of the connection ... just a plug on the outside wall ... 10% with changeover switch and dedicated DB's.

    I have 2 installation this week and ton more enquiries for generator and inverter installations ... in fact so many that I have decided to go register as a reseller at a few of the inverter suppliers.

    One thing I will be adding to the changeover switch (63 amp) and plug (32 amp it covers most small generator) ... a current clamp maybe even a voltmeter ... so that customers can see how much load is on the generator as they reset the circuit breakers.

    VOV ... COC HOD ... it doesnt matter what the customer plans to connect to the socket ... its not your problem ... just like the electrical installation ...its not the electricians responsibilty ... it is up to the owner to make the right choice ... just make sure you put a note in your invoice "VOV generators not to b used".
    Comments are based on opinion...not always facts....that's why people use an alias.

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    I am going to do a few mods to the current setup ... the easiest way to do it ... in this example a 60 amp single phase supply.

    Mount a weather proof DB next to or below the meter box.

    Fit a changeover switch to suit the meter circuit breaker ... in this case a 63 amp.

    fit a 25 amp double pole breaker next to the changeover switch ( overload protection for the genrator ... a new addition)

    fit a panel mount voltage and current meter next to the breaker ... and an indicator light if you feel the meter is not good visual indicator

    Mount a 32 amp weartherproof male socket outlet below the weather proof DB ... even if out the weather ... it better with the cap over the plug pins.

    Ready for most generators.

    Please feel free to add a better solution if you have one.
    Comments are based on opinion...not always facts....that's why people use an alias.

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    For those who feel it is safer to fit a Za plug ... feel free to replace the 32 amp with Za socket ... so that you dont have to use an extension
    Comments are based on opinion...not always facts....that's why people use an alias.

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    The generator arrived ready to connect ... an interesting note on various locations on the generator

    "Manufactured according to SANS 1007:2010 STANDARDS"

    7500 watts

    PF 1

    To make sure everything is safe ... labels ... lables and more labels.

    The customer asked why I didnt connect the cable to the plug on the 16 amp socket outlet on the front of the generator ... but instead directly to the circuit breaker on the generator ...via a gland ... the the 16 sockets are only rated to 16 amps and therefore cannot carry the full 7500 watts (32 amps).

    I am wondering if it is not a good idea to knock a spike into the ground below the changeover switch and bond the wire from the spike to the supply earth at the same point where I connect the neutral from the socket to the mains earth ... it seems pointless ... but rather make it look like I know what I am doing.
    Comments are based on opinion...not always facts....that's why people use an alias.

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    By the way the generator is brand new ... it must be illegal because it has 2 x 3 pin SANS 164-1 socket outlet next to each other and no ZA plug provided
    Comments are based on opinion...not always facts....that's why people use an alias.

  11. #10
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    Rollling out the stores as people struggle to stay in bussiness with stage 4 load shedding ... and talk of stage 6 ... how do people know if these are legal or not?

    YES IT IS DANGEROUS TO FIT A PLUG TOP ON EACH END OF THE EXTENTION CORD AND PLUG ONE INTO THE GENERATOR AND ONE IN THE SOCKET OUTLET IN YOUR HOUSE.

    https://www.builders.co.za/Tools-%26...00000000460483


    https://www.builders.co.za/Tools-%26...00000000643611
    Comments are based on opinion...not always facts....that's why people use an alias.

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