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Are RCD's Required?

Nano Brewery
Hi, looking to understand if an RCD would be a required regulation (and/or just highly recommended) in the following situation.  The additional cost of installing four or five 3-Phase RCDs is quite substantial and I would prefer to avoid it if still deemed as safe and not legally required.  Earthing system is TN-C-S.


For connecting up 4x Immersion Elements (9kW, 9kW, 6kW, 3kW) in Brewery Tanks I am looking at either:


A.  SWA Cable clipped direct to basket from the Control Panel to IP rated Plugs/Sockets mounted on the wall.  Then floating SY Cable (recommended by electrician) from the wall to the Tanks, which is about a 2m run.  Thinking Plugs/Sockets just to make life easy if I ever want to move things around and also for easier access for cleaning.


B.  Same as above but swapping the Plugs/Sockets for Isolators.


Look forward to your feedback and opinions.  Cheers.
  • 0
    IF there are no plugs and sockets, then the RCDs are not required by regulation, so long as the loop impedance is low enough (the fault current would be high enough)  to operate whatever MCB or fuse is protecting.

    Having said that, where liquids and electrics meet RCDs are a very nice thing to have, even if the RCD covers more than one immersion heater.

    (https://www.tlc-direct.co.uk/Products/WYWRS32slash4.html) sort of sized object.
  • 0
    I do not expect you to be heating things if no operator is present, so a single RCD covering everything would be perfectly satisfactory. I suggest the plugs and sockets are a good idea in any food area, as cleaning is much easier if things are all on castors. That and a 3ph board are not too expensive and save the isolator cost completely, you simply unplug items to isolate. You may find 3 circuits, of 16A each perfectly satisfactory for the moment, with 16A BS4343 sockets (red) but leave space in the board for expansion later! IP67 ones are probably unnecessary unless you live in a permanent spray of water, which I doubt! Turn off the RCD before using a pressure washer.
  • 0
    I forgot to add that more than one socket is perfectly satisfactory on any circuit, as long as the breaker matches the socket size (16A).
  • 0
    You could have one RCD feeding 4 MCBs, feeding 4 sockets.... if you do not mind the small risk of it all going off together.
  • 0
    Could you not have an RCD incomer in the DB?
  • 0
    mapj1:

    Having said that, where liquids and electrics meet RCDs are a very nice thing to have, even if the RCD covers more than one immersion heater.

    (https://www.tlc-direct.co.uk/Products/WYWRS32slash4.html) sort of sized object.


    Cheers.  I was hoping to keep all elements on separate circuits, so if one develops a fault the other 3 will continue to operate, and any fault will be easier to detect.  At present the Control Panel has 6 individual circuits, with Rail Mounted Cartridge Fuses and Contactors installed on each.  I understand that the Control Panel can be fed either via a Henley Block or from the 3-Phase Distribution Board?  Wondering if an enclosure with RCD would be an option?... https://www.cef.co.uk/catalogue/products/1051602-3-module-insulated-ip65-enclosure


  • 0
    davezawadi (David Stone):

    I do not expect you to be heating things if no operator is present, so a single RCD covering everything would be perfectly satisfactory. I suggest the plugs and sockets are a good idea in any food area, as cleaning is much easier if things are all on castors. That and a 3ph board are not too expensive and save the isolator cost completely, you simply unplug items to isolate. You may find 3 circuits, of 16A each perfectly satisfactory for the moment, with 16A BS4343 sockets (red) but leave space in the board for expansion later! IP67 ones are probably unnecessary unless you live in a permanent spray of water, which I doubt! Turn off the RCD before using a pressure washer.


    Cheers David.  It does sound like the general consensus is to use an RCD.  Wondering if I'm worrying too much about things developing faults?  Maybe I should go with a single RCD feed from the 3-Phase Board to the Control Panel.  At present the Control Panel has 6 individual circuits, with Rail Mounted Cartridge Fuses and Contactors installed on each.  I do also need to be able to switch the individual elements (9kW, 9kW, 6kW, 3kW) on/off to control or ramp up temperatures.


  • 0
    Chris Pearson:

    Could you not have an RCD incomer in the DB?


    Cheers Chris.  I was hoping to keep all elements on separate circuits, and also have RCDs on all circuits, just so if one develops a fault the other 3 will continue to operate, and any fault will be quicker and easier to detect?


  • 0
    I don’t have any specialist knowledge on the subject of setting up and running a brewery.


    Are breweries potentially explosive locations? What does your risk assessment say about the possibility of explosions and other risks associated with the electrical installation?

    http://www.hazardexonthenet.net/article/60418/Hazard-assessment-in-the-brewing-and-distilling-industries.aspx
  • 0
    Nano Brewery:
    Chris Pearson:

    Could you not have an RCD incomer in the DB?


    Cheers Chris.  I was hoping to keep all elements on separate circuits, and also have RCDs on all circuits, just so if one develops a fault the other 3 will continue to operate, and any fault will be quicker and easier to detect?




    No, I wouldn't look at it that way. Each element will have its own MCB/fuse. A short circuit would trip the MCB, but not the RCD. A fault (i.e. to earth) might trip both. Ok, that is a bit of a bother if the whole lot goes off. I am not sure how that affects your business, but if it slows down a batch, is that an issue? If it occurred, you can still isolate the faulty element by its MCB.


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