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B-Type RCDs

  • 07-04-2019 9:33am
    #1
    Posts: 0 [Deleted User]


    Are installers really fitting B-type RCDs as outlined in the wiring regs for high frequency solar & battery inverters?


    Type-B.jpg


    I can't fathom any client wanting to pay more for a trip switch than their inverter cost..:confused:


    Installers wouldn't perchance be fitting Trip Curve B MCB/RCBO devices instead?..:(


    Has anyone got a source for inexpensive properly certified jobbers?


Comments

  • Posts: 0 [Deleted User]


    Would any users with a since ~2016 PV and or battery install mind awfully posting pics of their solar and or hybrid inverter consumer unit(s) with the circuit breaker text in focus, please?
    And state what the inverter make and model is.


    I'd like to see what the industry standard is.
    Thx.


  • Registered Users Posts: 3,612 ✭✭✭ Dardania


    What's the problem here - is it meant to be an RCD (as in earth fault) protection only, rather than over current?


  • Posts: 0 [Deleted User]


    It's a class of RCD (RCCB - Earth Fault) that detects both DC and AC and they're north of €500.
    Standard RCDs can fail to operate in fault conditions due to injected DC from the lack of isolation from the battery or PV in a high frequency topography inverter (most are because it's "cheaper").

    It's in the building regs that there has to be one and it's in the installer notes for the SEAI grant that there has to be one. I'm wondering are people getting them and are the installers equipped with the facilities to test them.


  • Registered Users Posts: 3,612 ✭✭✭ Dardania


    Wow - I never knew about this but it makes sense.


  • Posts: 0 [Deleted User]


    Clicky

    Another feather in the cap for low-frequency transformer inverters.


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  • Moderators, Society & Culture Moderators Posts: 31,304 Mod ✭✭✭✭ Gumbo


    I'll check mine later.
    I only have Solar PV-Invertor-Divertor. No battery.


  • Registered Users Posts: 3,612 ✭✭✭ Dardania


    Clicky

    Another feather in the cap for low-frequency transformer inverters.

    Thinking a bit further on this - would a capacitor not help a lot here to filter out DC?


  • Posts: 0 [Deleted User]


    Dardania wrote: »
    Thinking a bit further on this - would a capacitor not help a lot here to filter out DC?

    Nope.


  • Registered Users Posts: 2,386 ✭✭✭ Tow


    The use of Type B is touched on here, at 26 minutes. AC will be banned.
    I don't think he covers PV in the video, but maybe wrong.

    https://youtu.be/bLIyTYhWs_0?t=1558


  • Registered Users Posts: 3,612 ✭✭✭ Dardania


    Nope.

    Why?


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  • Posts: 0 [Deleted User]


    Dardania wrote: »
    Why?
    Capacitors are DC.
    DC is the problem for A, AC and F type RCDs


  • Registered Users Posts: 3,612 ✭✭✭ Dardania


    Capacitors are DC.
    DC is the problem for A, AC and F type RCDs

    So, the capacitor ought to filter out the DC...if I remember my electrical engineering correctly?


  • Posts: 0 [Deleted User]


    Capacitors resist changes in voltage. They are DC collectors. The problem with regular A and AC RCDs is their ability to operate within specified parameters with a DC presence on their sense conductors.
    If anything they would make it worse/do nothing & reduce power factor.

    Capacitors can be used to filter ripple and noise, and smooth a chopped/pulsed or variable voltage.
    They do not make installations compliant with ET101.

    Whether or not real world results could vary; it would prove extremely difficult to test it's correct operation in normal operating conditions as results would depend massively on what the inverter input is and in the case of battery inverters what the appliance line noise is.


  • Posts: 0 [Deleted User]


    You could fulfil thuther clause
    ET101 wrote:
    Where the PV system cannot, by reason of its construction, feed DC currents into the electrical installation (i.e. AC system), a Type B RCD shall not be required, and electrical protection of the AC circuit shall be in accordance with ET101:2008

    ..with a for example €500 isolation transformer :pac:


  • Moderators, Society & Culture Moderators Posts: 31,304 Mod ✭✭✭✭ Gumbo


    Sorry for the long delay but this is what’s fitted in my fuse board from the Solar PV. Mine were fitted around September 2017.


  • Posts: 0 [Deleted User]


    Yurp. That's a non-compliant A type. I'd take that up with your RECI...they owe you a very expensive circuit breaker.

    If your inverter is fully isolated from the primary input it is ok, you can ask them this. I'm sure they will know the difference.


  • Moderators, Society & Culture Moderators Posts: 31,304 Mod ✭✭✭✭ Gumbo


    Yurp. That's a non-compliant A type. I'd take that up with your RECI...they owe you a very expensive circuit breaker.

    If your inverter is fully isolated from the primary input it is ok, you can ask them this. I'm sure they will know the difference.

    Would be interesting to see if anyone has the Type B switch.
    Where in the regs is the requirement?
    Is it ET101?

    Also, my EV Charger is a type A switch.
    According to your link it should be a Type B also.


  • Closed Accounts Posts: 844 H.E. Pennypacker


    Here's mine - I've no idea what to look for so any info welcome. Inverter is a Trannergy SGN1800TL:


  • Moderators, Society & Culture Moderators Posts: 31,304 Mod ✭✭✭✭ Gumbo


    Here's mine - I've no idea what to look for so any info welcome. Inverter is a Trannergy SGN1800TL:

    It says B20 so initial thoughts is that it’s a Type B switch BUT, the logo is the same as mine and when crossed referenced on the Hager site, it’s a Type A, same as mine.


  • Posts: 0 [Deleted User]


    Here's mine - I've no idea what to look for so any info welcome. Inverter is a Trannergy SGN1800TL:

    That's not an RCD that's an RCBO (over current trip curve B)...also non-compliant.

    It's in the regs ET101:2008
    Subsection: 712.411.3.02

    Yes EV chargers are required to have B type RCD fitted too.
    EV charging specific RCDs are available for this.


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  • Moderators, Society & Culture Moderators Posts: 31,304 Mod ✭✭✭✭ Gumbo


    That's not an RCD that's an RCBO (over current trip curve B)...also non-compliant.

    It's in the regs ET101:2008
    Subsection: 712.411.3.02

    Yes EV chargers are required to have B type RCD fitted too.
    EV charging specific RCDs are available for this.

    Thanks. I’ll check those regs during the week.
    2019 version due for release in a few months also.


  • Registered Users Posts: 3,292 ✭✭✭ 0lddog


    Im wondering what the Regs in countries that offer a FIT that encourages domestic microgeneration require.

    Anyone familiar with, say, UK / German Regs ?


  • Posts: 0 [Deleted User]


    18th Edition Uk to include installation and testing of B-Type RCDs for EVs and non-isolated PV inverters. Spurring a revision and up-spec of multi-function tester requirements for installation testing.

    German company SMA has had the requirement of a B-Type RCD for their Sunny Island Range since I expect, the product release.


  • Posts: 0 [Deleted User]




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