Results 1 to 10 of 23

Thread: kA ratings

Threaded View

Previous Post Previous Post   Next Post Next Post
  1. #9
    Diamond Member AndyD's Avatar
    Join Date
    Jan 2010
    Location
    Cape Town
    Posts
    4,923
    Thanks
    576
    Thanked 934 Times in 755 Posts
    Quote Originally Posted by ConcernedHomeowner View Post
    .........In researching more about my Earth Leakage Breaker, it appears that it has overcurrent protection at 30A......
    I'm not sure if those old Heinemann RCD's had overload protection, I suspect not because there's an overload main breaker (MCB) to the left of it so that would be duplicating overload protection if it does. The 30A it states on the front might be an indication of the maximum load it's rated to be able to disconnect at if there's an earth leakage fault. Maybe another member here has a better memory than me and can confirm if it has overload protection.



    Quote Originally Posted by ConcernedHomeowner View Post
    With the addition of the bar fridge onto my one plug circuit (which is on the same phase as my geyser), is it possible that if the fridge motor kicks in at the same time as the geyser and a few other appliances are on, it shoots the current past 30A and that causes the breaker to trip, rather than an Earth Leakage? The other factor about rainy days is that that is when my geyser will typically go on, as it is a solar geyser, and the element only kicks in when the sun doesn't get the water to a particular temperature. So the moisture from the rain may be a red herring.
    Earth leakage is a cumulative problem and even more so with a 3-phase RCD. It sees the total leakage on all 3 phases and if that total leakage exceeds 30mA it trips. Generally speaking it's better to have 3 separate single phase RCD's, it's causes a lot less inconvenience if there's a tripping fault and that alone may be good enough justification to replace it assuming there's space in the board for 3 single phase units and 3 associated neutral bars. As you say earth leakage tripping faults can be confusing if you're trying to solve them by deduction, I made a thread somewhere with advice for homeowners with tripping problems, I'll see if I can find it later and post a link here when I've got more time.

    Quote Originally Posted by ConcernedHomeowner View Post
    The one electrician that I worked with that didn't immediately start advocating that I spend lots of money is coming back on Saturday and he will do more tests. He has come with a good reference from someone I can trust who knows more about electrical installations than I do. So far he has given me more confidence than the others I have worked with. I will chat with him about who purchases what, but he will be the one doing the installing. I have opened my DB board to check which circuits are on which phases, but I'm not going to be installing breakers. I am reading a lot and finding out more, not so that I can rewire my house and DB board, but so that I can know what the legal requirements are and what proposals are required and which are fanciful. Based on my research I can see that a lot of the work that has been done at our house is not to appropriate standards. But I hold myself responsible for not knowing more and checking up better. We rushed forward in the past with repairs and upgrades, rather than checking facts and ensuring standards. So now I want to systematically look at matters and improve the wiring in the entire house over the next year (we will be renting it out for seven months next year, and need all things to be in good order before March 2019).
    I feel for you and you're in the same boat as many home owners, sometimes they've unknowingly been let down by unscrupulous contractors and sometimes they're to blame for knowingly cutting corners to save money. I'm afraid the electrical legislation holds the home owner as being the person responsible for the electrical installation and its compliance.

    Quote Originally Posted by ConcernedHomeowner View Post
    What is your company name, or how can I contact you? If things don't work out with the electrician coming on Saturday, perhpas I can engage your services? From your profile it appears you are in Cape Town.

    On the kA rating, can I just phone the municipality then? From what someone said to me at an electrical wholesaler, 3kA is more than enough, but I'd like to be on the safe side.
    3kA would usually suffice, especially on a 40A main supply but it could be higher if for example you happen to be close to the Eskom transformer or if for some reason you have an oversized supply cable. You could enquire with the municipality but it might be a tedious process, the best way to be 100% sure would be to test the PFC which would take a sparky with the right test equipment literally 2 or 3 minutes.

    Thanks for the offer to engage my services but I'm afraid I'm not set up to do domestic electrical, primarily I design and build control panels for the commercial market. I'm also located near Noordhoek which is nearly an hour from Tableview. Maybe take up SeanM on his kind offer of a free test, I'm sure he'd also give you some good advice on your best way forward as well if he sees the DB first hand.
    _______________________________________________

    _______________________________________________

  2. Thank given for this post:

    ConcernedHomeowner (25-May-18), Dave A (25-May-18)

Similar Threads

  1. Eskom or the wind ?
    By daveob in forum General Chat Forum
    Replies: 11
    Last Post: 05-Oct-10, 06:59 AM
  2. Listener AR ratings - how they work?
    By garthu in forum Marketing Forum
    Replies: 1
    Last Post: 29-Aug-10, 10:23 PM
  3. Downrated credit ratings - how will this affect us?
    By Dave A in forum Business Finance Forum
    Replies: 1
    Last Post: 13-Nov-08, 08:13 AM

Did you like this article? Share it with your favourite social network.

Did you like this article? Share it with your favourite social network.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •