Supply upgrade advice (25Amp>32Amp)

Discussion in 'Electricians' Talk' started by RossNE, Mar 18, 2019.

  1. RossNE

    RossNE New Member

    Hi all, I'm working in a restaurant who require a replacement dishwasher due to excessive break downs of their existing, and i'm looking for advice.

    Existing machine details on site:

    9kW. 400v 3ph. 20Amp.
    Board Supply:
    Cable size, 2.5mm.
    Overcurrent Device, 25Amp

    What I want:
    A better performing 16.3kW machine. 400v 3ph. 32Amp.

    I’m aware we need to upgrade the breaker from a 25A to a 32A. I’m not an electrician so I’d just like a brief explanation of what works are required to upgrade this supply please if anyone can advise, it’ll help me provide better advice on site in future? Is it a case of looking at this information and knowing the works can definitely go ahead, or is there more to this that could mean I can only put in another 25A machine?

    Thank you,
  2. Coloumb

    Coloumb Well-Known Member

    The 2.5mm cable CSA is too small for a 32a breaker. You would need to run in a bigger cable for this to work.

    A 25a fuse (I assume?) is pushing it a bit on 2.5mm already.
  3. spirits are real 2016

    spirits are real 2016 Active Member

    then you need to call in a electrician to do the job safely.
  4. Bob Rathbone

    Bob Rathbone Well-Known Member

    You can only protect a 2.5mm cable with a 32A breaker in motor circuits, or circuits where the breaker only provides earth fault and short circuit protection, overcurrent protection is then provided at the load end of the cable by overload devices in the motor starter, additional fuses, or a load that is incapable of overloading the cable.
    You need a new cable run, bigger, may be 4mm or 6mm if the run is long. You are not an Electrician, hire one to do the job.
  5. RossNE

    RossNE New Member

    Thanks guys.

    My original post did sound like I was looking to do the work myself but I will definitely be getting a qualified electrician in. I was more-so looking at an explanation to tell my customer why we need an electrician in. Thanks for you help.

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