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200Kva Generator Wash Plant
Posted: Tue Jul 06, 2021 12:59 pm
by Chopper
We have a customer with a new Shingle Wash Plant that is to be supplied by a 200kva generator. The wash plant has 2 * 30kw pumps, 2 * 4kw vibrators and a 7.5kw hydraulic power pack. Control gear to be in an enclosure mounted on the wash plant. Generator hard wired to control panel.
What earthing options will be required? MEN at generator, MEN at Control panel, Earth Peg or other?
Thanks
Re: 200Kva Generator Wash Plant
Posted: Tue Jul 06, 2021 4:12 pm
by AlecK
Fixed installation?
Or mobile / relocatable?
This determines which Standards apply
And in turn that determines the earthing arrangements
Re: 200Kva Generator Wash Plant
Posted: Tue Jul 06, 2021 7:30 pm
by Chopper
Generator and Wash Plant on concrete pads, so fixed for the foreseeable future.
Re: 200Kva Generator Wash Plant
Posted: Wed Jul 07, 2021 10:30 am
by AlecK
As a fixed installation, the main applicable Standard is "3000".
As non-domestic, choice of Part 1 or Part2; but if it was Part 1 you wouldn't be asking the questions because all this would be part of the certified design.
As a Part 2 installation; earthing requirements are set in Section 5; but may be modified by a companion Standard.
In this case, with genset as sole supply, the installation is a standalone power system; which ESR 60 requires to also comply with AS/NZS 4509.1.
"3000" clause 7.3 sets requirements for connection of a generating system (any type) to an installation, and 7.3.2 specifically requires the engine-driven generators to comply with AS/NZS 3010. Note that while the version cited in ESRs is 2005 edition; in this case we're not following an ESRs requirement to comply with "3010", but with a requirement within "3000" - so that means the latest edition (2017). Which includes guidance on why an earth electrode at genset is not only not required, but not wanted at all.
Details can be found in these documents; but basically the installation earthing is absolutely normal; except that
a) there's no connection to the earthed neutral (PEN) of a network's distribution system; and
b) there's a PEC between the installation earthing system and the genset frame.
The MEN link will be at the MSB as usual.
Technically it isn't an "MEN"system, as there's only one connection to earth. So really it's not an "MEN link", just a "N-E link". But the name is less important than the requirement to have it; and it goes at the same place as an MEN link for an installation supplied from an MEN supply system.
There must be NO N-E connection at the genset.