Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie

fitting RCBO on 9.5kW pumped triton shower

Options
2

Comments

  • Options
    #32
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    cluelez wrote: »
    this is the correct statement.

    When the test was performed the load showed 33amp's between the shower and the board.

    Would this means that the protective device at 40amp is suitable for this setup?

    the 9.5 will read higher than 33amps

    you will be fine with 40amp whether its under or a bit over 40

    nothing bad will happen


  • Options
    #33
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    2011 wrote: »
    A load of less than 42A can be fed from a 40A RCBO all day long without it tripping.


    it won't trip

    but it's bad practice


  • Options
    #34
    2011
    Moderators, Home & Garden Moderators, Technology & Internet Moderators, Regional East Moderators Posts: 12,594 Mod ✭✭✭✭2011


    mikehammer67 wrote: »
    it won't trip

    but it's bad practice

    Why?


  • Options
    #35
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    2011 wrote: »
    Why?

    it's not standard practice to have fixed load exceed rating of protective device

    assuming it does


  • Options
    #36
    2011
    Moderators, Home & Garden Moderators, Technology & Internet Moderators, Regional East Moderators Posts: 12,594 Mod ✭✭✭✭2011


    mikehammer67 wrote: »
    it's not standard practice to have fixed load exceed rating of protective device

    assuming it does

    Protective devices are instaleld to protect the cable.

    I would argue that a 40A RCBO would provide better protection to than a 45A RCBO because it will trip far sooner if an overload were to occur.


  • Advertisement
  • Options
    #37
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    frankmul wrote: »
    What value is the voltage at when you have the shower running. I'm calculating a figure of around 180 volts


    Is it written on the ET101 Certificate of Compiance?

    let me read to you what were the tests and outcomes:

    Tests:

    Min. Insulation Resitance: >999M(Omega)

    Polarity and Earthing Verified: YES

    Resistance of Protective Conductor: .4 (Omega)

    Fault Loop Impedance: .5 (Omega)

    and Rating & Type of Associated Protective Device: 40B A

    Trip Time 30mA RCD AT 30mA: .29ms

    Equipment Bonding Verifited: N/a

    Other than that I don't know as I didn't test it.

    Electrician did.


  • Options
    #38
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    2011 wrote: »
    Protective devices are instaleld to protect the cable.

    I would argue that a 40A RCBO would provide better protection to than a 45A RCBO because it will trip far sooner if an overload were to occur.

    Which one would trip sooner?


  • Options
    #39
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    2011 wrote: »
    Protective devices are instaleld to protect the cable.

    I would argue that a 40A RCBO would provide better protection to than a 45A RCBO because it will trip far sooner if an overload were to occur.

    no

    nominal current < rating of device

    rules 533
    if load is 42 breaker should be higher

    it wont cause a problem though


  • Options
    #40
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    2011 wrote: »
    I would be interested to know why they think a 40A would not be suitable. I have never used a 45A RCBO and I have conneceted plently of 9.5 kW showers without any issues. A load of less than 42A can be fed from a 40A RCBO all day long without it tripping.



    Yup, that is what I would expect, 40A B type (IΔn 30mA)

    I asked them this question, as of today - no response.


  • Options
    #41
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    mikehammer67 wrote: »
    the 9.5 will read higher than 33amps

    you will be fine with 40amp whether its under or a bit over 40

    nothing bad will happen

    Why do you think it would be higher than 33amps?

    I've seen sparky did hold a multimeter. I have one of these and I may perform own test later...


  • Advertisement
  • Options
    #42
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    cluelez wrote: »
    Why do you think it would be higher than 33amps?

    I've seen sparky did hold a multimeter. I have one of these and I may perform own test later...

    stop the lights:pac:


  • Options
    #43
    frankmul
    Registered Users Posts: 378 ✭✭frankmul


    cluelez wrote: »
    Why do you think it would be higher than 33amps?

    I've seen sparky did hold a multimeter. I have one of these and I may perform own test later...

    Be careful! As far as I know, a multimeter will not read greater that 10 amps, you need to use a grip ammeter.
    I relation to the 33 amps, if the voltage at the shower was 230 volt then a 9.5 kw shower would draw over 40 amps, if it only drew 33 amps then the voltage must have dropped to under 200 volts and your shower is running at about 6.5 kw


  • Options
    #44
    frankmul
    Registered Users Posts: 378 ✭✭frankmul


    mikehammer67 wrote: »
    180v?

    maximum allowable is 4%

    i would just size protective device>9500/230 myself

    rather than measuring full load voltage at appliance

    Yes max allowed should be 4%, I would size as you said but you can also take diversity into account. Next size rcbo above 40 amp is a 50 amp.


  • Options
    #45
    SpaceTime
    Closed Accounts Posts: 9,088 ✭✭✭SpaceTime


    Bear in mind that the 10mA GFCIs used in the USA are calculated with different curves to the 30mA RCDs used in Europe. the NEC and IEC spec on those is quite different.

    I have read a few articles that would indicate that the level of protection from the two devices is very similar. Europeans are not using 30mA RCDs because they enjoy being electrocuted and Americans aren't using 10mA GFCIs because they love resetting trips.

    I can't remember the specifics, but it works out that the two devices are very much equivalent.

    The trip time on the European version was also quite different.


  • Options
    #46
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    SpaceTime wrote: »
    Bear in mind that the 10mA GFCIs used in the USA are calculated with different curves to the 30mA RCDs used in Europe. the NEC and IEC spec on those is quite different.

    I have read a few articles that would indicate that the level of protection from the two devices is very similar. Europeans are not using 30mA RCDs because they enjoy being electrocuted and Americans aren't using 10mA GFCIs because they love resetting trips.

    I can't remember the specifics, but it works out that the two devices are very much equivalent.




    30mA devices aren't used on 110v as they may not trip in the event of a shock

    10mA devices aren't 'generally' used on 230v as 30mA is adequate shock protection and also 10mA will be more prone to nuisance trip


  • Options
    #47
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    I'm not gonna touch anything.


  • Options
    #48
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    cluelez wrote: »
    I'm not gonna touch anything.

    ya

    watch out for the live wires if you change your mind:rolleyes:


  • Options
    #49
    SpaceTime
    Closed Accounts Posts: 9,088 ✭✭✭SpaceTime


    mikehammer67 wrote: »
    30mA devices aren't used on 110v as they may not trip in the event of a shock

    10mA devices aren't 'generally' used on 230v as 30mA is adequate shock protection and also 10mA will be more prone to nuisance trip

    There some difference in how the two bodies involved calculate the rating though too.


  • Options
    #50
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    mikehammer67 wrote: »
    ya

    watch out for the live wires if you change your mind:rolleyes:

    what are you talking about?

    your post sounds abusive.


  • Options
    #51
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    alright funny guy:pac:

    you're not a spark trolling by any chance or what's the story like...


  • Advertisement
  • Options
    #52
    mikehammer67
    Closed Accounts Posts: 699 ✭✭✭mikehammer67


    SpaceTime wrote: »
    There some difference in how the two bodies involved calculate the rating though too.

    what difference


  • Options
    #53
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    mikehammer67 wrote: »
    alright funny guy:pac:

    you're not a spark trolling by any chance or what's the story like...

    So now me being spark?

    Oh no... I just like the DIY


  • Options
    #54
    mozil
    Registered Users Posts: 101 ✭✭mozil


    http://youtu.be/FONN-0uoTHI


  • Options
    #55
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    mozil wrote: »
    http://youtu.be/FONN-0uoTHI

    what is that?


  • Options
    #56
    .G.
    Registered Users Posts: 5,415 ✭✭✭.G.


    As mentioned by 2011 the MCB part of the protective device is there to protect the cable,The correct way to design circuit is to find the design load,find a suitable cable which is capable of carrying that load in its installed conditions and then find a suitable protective device to protect that cable from overload.

    Pretty much everywhere I've measure in Dublin the nominal volatge is nearly always 233v or 234v. Assuming that's the case here we are looking at around 40.77 amps from a 9.5KW shower. OP has already wired it in 10sq which,depending on the installation method is more than capable of carrying that load. Your only choice to protect is a 40a RCBO since 50a is too high. The operating range on most of these protective devices for overload is 1.16 x In to 1.45 x In so in reality a 40A RCBO will carry at least 46A without ever tripping,and even over that it might take hours to trip.

    No issue with using it here IMO. I'd have just used an 8.5Kw myself.


  • Options
    #57
    blueterrier
    Registered Users Posts: 5 ✭blueterrier


    "As mentioned by 2011 the MCB part of the protective device is there to protect the cable,The correct way to design circuit is to find the design load,find a suitable cable which is capable of carrying that load in its installed conditions and then find a suitable protective device to protect that cable from overload."

    Protecting the cable, while necessary and important is secondary to the protection of life! There's a reason why certain jobs require training. There is proposed legislation to make it illegal for unqualified persons to carry out electrical installation works in domestic premises, although why the legislation limits itself to domestic premises is beyond me.


  • Options
    #58
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    superg wrote: »
    As mentioned by 2011 the MCB part of the protective device is there to protect the cable,The correct way to design circuit is to find the design load,find a suitable cable which is capable of carrying that load in its installed conditions and then find a suitable protective device to protect that cable from overload.

    Pretty much everywhere I've measure in Dublin the nominal volatge is nearly always 233v or 234v. Assuming that's the case here we are looking at around 40.77 amps from a 9.5KW shower. OP has already wired it in 10sq which,depending on the installation method is more than capable of carrying that load. Your only choice to protect is a 40a RCBO since 50a is too high. The operating range on most of these protective devices for overload is 1.16 x In to 1.45 x In so in reality a 40A RCBO will carry at least 46A without ever tripping,and even over that it might take hours to trip.

    No issue with using it here IMO. I'd have just used an 8.5Kw myself.

    But surely this wouldn't mean that if there is a short it would fry me in the shower without tripping?


  • Options
    #59
    .G.
    Registered Users Posts: 5,415 ✭✭✭.G.


    cluelez wrote: »
    But surely this wouldn't mean that if there is a short it would fry me in the shower without tripping?

    Overload is different to short circuit. Overload acts on the thermal side of the device and can take hours to trip. A short circuit would result in a massive current flow causing the device to trip instantly.

    On top of that an RCBO has earth leakage protection too. You are quite safe if the sparks who certed it says you are.


  • Options
    #60
    .G.
    Registered Users Posts: 5,415 ✭✭✭.G.


    blueterrier wrote: »
    "As mentioned by 2011 the MCB part of the protective device is there to protect the cable,The correct way to design circuit is to find the design load,find a suitable cable which is capable of carrying that load in its installed conditions and then find a suitable protective device to protect that cable from overload."

    Protecting the cable, while necessary and important is secondary to the protection of life! There's a reason why certain jobs require training. There is proposed legislation to make it illegal for unqualified persons to carry out electrical installation works in domestic premises, although why the legislation limits itself to domestic premises is beyond me.

    Not sure what your point is and the new rules are discussed in a seperate thread.My point is about the argument in this thread about whether or not a 40a rcbo is suitable for this circuit.

    You'll find my view on the pointless new legislation in the other thread.


  • Advertisement
  • Options
    #61
    cluelez
    Registered Users Posts: 157 ✭✭cluelez


    superg wrote: »
    Overload is different to short circuit. Overload acts on the thermal side of the device and can take hours to trip. A short circuit would result in a massive current flow causing the device to trip instantly.

    On top of that an RCBO has earth leakage protection too. You are quite safe if the sparks who certed it says you are.

    Yep I confirm that on the top of an RCBO there is earth leakage protection installed. (I know for sure).

    Thanks.


Advertisement