Page 1 of 3 123 LastLast
Results 1 to 10 of 23

Thread: Home electrical safety devices

  1. #1
    New Member
    Join Date
    May 2022
    Location
    South AFrica
    Posts
    3
    Thanks
    0
    Thanked 0 Times in 0 Posts

    Home electrical safety devices

    Hello all. Recently we had our very old Heinemann ELCB replaced with an RCCB without overload protection. The lack of overload protection made me wonder if we really have all the needed electrical safety devices.

    I'm not an electrician and I'm working from the assumption that everything I thought I knew about electricity is wrong. I am a total noob when it comes to electricity. I have a few questions I'm hoping you'll be able to answer.


    The installation...

    We have 3-phase power.

    We don't have access to the municipal meter box on the sidewalk. Its post-paid power.

    Here is our own meter box on the outside of the house. There used to be a switch/breaker in that opening below the round window, but was replaced by the switchover device on the left we had installed to connect the generator.
    Click image for larger version. 

Name:	1_Own_meterbox.jpg 
Views:	34 
Size:	73.2 KB 
ID:	8523
    Click image for larger version. 

Name:	2_Switchover_model_nr.jpg 
Views:	30 
Size:	42.8 KB 
ID:	8524


    Here is the distribution board and the newly installed RCCB.
    Click image for larger version. 

Name:	3_DB.jpg 
Views:	37 
Size:	38.1 KB 
ID:	8525
    Click image for larger version. 

Name:	4_RCCB.jpg 
Views:	38 
Size:	46.2 KB 
ID:	8526

    Here is the old ELCB we had replaced. Pressing the test-button didn't trip the switch. Electrician confirmed the device is faulty. I couldn't find out if it had built-in overload protection.
    Click image for larger version. 

Name:	5_ELCB.jpg 
Views:	30 
Size:	97.0 KB 
ID:	8527


    My questions...

    (I love full detailed explanations, so please don't hesitate to elaborate)

    1) I understand the new RCCB won't protect against short-circuits (live wire touching neutral) or any other situation where too much power flows through (unless the difference between the live and neutral is 30 milliAmps or greater), correct?

    2) The switches labeled "plugs", "ligte", etc are the miniature circuit breakers (MCB's) and they're supposed to trip if too much power flows through the circuit, correct?

    3) What are those numbers printed on what I assume are the MCB's?

    4) Should I have a circuit breaker (that trips if too much power flows through) re-installed in the meter-box on the outside of the house?

    5) Should the municipal meter box on the sidewalk have a circuit breaker with overload protection?

    6) I record our municipal meter readings every month (read at the municipal meter box on the sidewalk). There are 3 meters (since we have 3-phase power). One meter always has a low monthly usage, the other one a higher usage and the last one the highest usage. Since the new RCCB was installed it seems the highest-usage-meter now has the second highest usage, while the previous second-highest-usage-meter now has the highest usage. I assume this could be because the wires in the distribution board might not have been connected to the new RCCB exactly the same way they were connected to the old ELCB. Should I be worried?

    7) Can you see anything missing/wrong safety-wise?

    Thanks in advance.

  2. #2
    Silver Member
    Join Date
    Jul 2008
    Location
    Germiston, South Africa
    Posts
    381
    Thanks
    21
    Thanked 46 Times in 42 Posts
    As indicated on the new earth leakage unit there needs to be a circuit breaker added and it must be on the load side of the earth leakage. (6.8.1)
    If the is no space available for an extra circuit breaker then a new earth leakage with integrated protection must be used

    Sent from my SM-A528B using Tapatalk
    To make a mistake is human, to learn from that mistake is knowledge and knowledge is strength.

  3. #3
    Bronze Member
    Join Date
    Mar 2022
    Location
    South Africa
    Posts
    189
    Thanks
    3
    Thanked 8 Times in 8 Posts
    I still have one of those old Dymo label printers

  4. #4
    Bronze Member
    Join Date
    Mar 2022
    Location
    South Africa
    Posts
    189
    Thanks
    3
    Thanked 8 Times in 8 Posts
    If you want people to comment on the installation, you would need to supply a lot more details, looking at those pics are liking asking a mechanic to comment on an engine with the bonnet closed.

  5. #5
    Bronze Member
    Join Date
    Feb 2022
    Location
    South Africa
    Posts
    117
    Thanks
    0
    Thanked 7 Times in 6 Posts
    Like Leecatt said you need a RCD with overload protection or a seperate main switch at point of supply disconnecting phases and neutral.Are you using a 3 phase generator? Is the changeover switch a 4 pole if you are using a 3 ph generator. Reason for different readings on kwh meters loads between phases are not balanced.

  6. #6
    Gold Member
    Join Date
    Jun 2017
    Location
    Port Elizabeth
    Posts
    727
    Thanks
    19
    Thanked 189 Times in 158 Posts
    My questions...

    1) I understand the new RCCB won't protect against short-circuits (live wire touching neutral) or any other situation where too much power flows through (unless the difference between the live and neutral is 30 milliAmps or greater), correct?
    That is correct - the RCCB that is installed is an isolator type and will only trip on leakage to earth.

    2) The switches labeled "plugs", "ligte", etc are the miniature circuit breakers (MCB's) and they're supposed to trip if too much power flows through the circuit, correct?
    Correct

    3) What are those numbers printed on what I assume are the MCB's?
    If you are referring to the 10 on the Circuit breaker for lights - That is the max amount of current that cab flow , being 10Amps

    4) Should I have a circuit breaker (that trips if too much power flows through) re-installed in the meter-box on the outside of the house?
    There should be a C/Breaker in your meter box to protect the change over switch and wiring - It needs to be rated correctly

    5) Should the municipal meter box on the sidewalk have a circuit breaker with overload protection?
    Generally I would expect the meter box to have protection or it could be on a pole - Depends on the set up

    6) I record our municipal meter readings every month (read at the municipal meter box on the sidewalk). There are 3 meters (since we have 3-phase power). One meter always has a low monthly usage, the other one a higher usage and the last one the highest usage. Since the new RCCB was installed it seems the highest-usage-meter now has the second highest usage, while the previous second-highest-usage-meter now has the highest usage. I assume this could be because the wires in the distribution board might not have been connected to the new RCCB exactly the same way they were connected to the old ELCB. Should I be worried?
    It sounds like the phases were swopped around on the installing of the new ELU - It should not be a problem if your equipment is all single phase .If you have 3 phase motors then the motors could be going the wrong way.
    With that said , it could also have been changed around twice , meaning that the direction could still be correct

    7) Can you see anything missing/wrong safety-wise?
    As mentioned previously , difficult to comment when you cannot see everything

  7. #7
    Site Caretaker Dave A's Avatar
    Join Date
    May 2006
    Location
    Durban, South Africa
    Posts
    22,438
    Thanks
    3,270
    Thanked 2,646 Times in 2,229 Posts
    Blog Entries
    12
    Quote Originally Posted by stuffies View Post
    7) Can you see anything missing/wrong safety-wise?
    There is a 45 amp circuit breaker marked as a PLUGS circuit which merits closer investigation.

  8. #8
    Bronze Member
    Join Date
    Mar 2022
    Location
    South Africa
    Posts
    189
    Thanks
    3
    Thanked 8 Times in 8 Posts
    There is enough evidence in the photos to open a full investigation.

  9. #9
    New Member
    Join Date
    May 2022
    Location
    South AFrica
    Posts
    3
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Thank you everyone! My dayjob and loadshedding kept me from replying sooner.

    All of you basically confirmed my suspicions that all is not right. In particular, there is a lack of overload protection. I don't really trust the MCB's tripping-ability any more, since they are as old as the previous ELCB (at least 40 years old), which was old enough to not work correctly anymore. So the MCB's may or may not work.

    So as a minimum (as I suspected) it appears the MCB's need replacement and a circuit breaker needs to be installed in the meterbox (our own, not the municipal box). A proper investigation will probably reveal more.

  10. #10
    New Member
    Join Date
    May 2022
    Location
    South AFrica
    Posts
    3
    Thanks
    0
    Thanked 0 Times in 0 Posts
    Quote Originally Posted by Leecatt View Post
    As indicated on the new earth leakage unit there needs to be a circuit breaker added and it must be on the load side of the earth leakage. (6.8.1)
    If the is no space available for an extra circuit breaker then a new earth leakage with integrated protection must be used

    Sent from my SM-A528B using Tapatalk
    Thankyou. The "6.8.1" seems to refer to a regulation? Where can I read more on this?

Page 1 of 3 123 LastLast

Similar Threads

  1. Home alterations and electrical plans question
    By adrianh in forum Electrical Contracting Industry Forum
    Replies: 6
    Last Post: 02-Oct-20, 11:34 PM
  2. [Question] Installing new electrical outlets in my home
    By julies in forum Electrical Contracting Industry Forum
    Replies: 6
    Last Post: 26-Aug-14, 06:22 AM
  3. Safety at home and work
    By adrianh in forum General Chat Forum
    Replies: 1
    Last Post: 13-May-14, 12:16 PM
  4. safety at home
    By murdock in forum General Chat Forum
    Replies: 5
    Last Post: 16-Jul-10, 08:24 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
  •