Most inline SMPS power supplies come with a floating output i.e. the 0V connection is NOT connected to EARTH. If not connected to a suitable ground (earth) point then you may experience static discharge when you contact any metal part in your system. The addition of a solid 'ground' will eliminate this.
Please note that the addition of such a grounding mechanism may introduce a 'ground loop' which may need to be treated.
Currently we can only support the Australian market (and countries using the same mains plugs).