This photo is of the inside of a well known and supposedly high quality (Australian) brand of plugbox which I would have unhesitatingly recommended to anyone until recently. Observe the earth contacts on the two left hand sockets, which have a much wider gap than the two on the right. The left hand pair are in fact not making contact with the earth pin on any standard 3 pin plug and this came to notice because the plugbox failed when connected for testing in a Portable Appliance Tester. This plugbox is less than a year old and the two left sockets would have each done less than 100 insert/removal cycles.
Since I have many older plugboxes which have withstood considerably more cycles and are more robustly built (yet were not expensive in their day) I asked the authorities in this country why this design was allowed to be sold in New Zealand and pass our national electrical safety certification standards. Their only response is that “these products are not designed for this type of use”. To which I would ask “why not”? Effectively what we are told is that it is acceptable to sell a plugbox that is designed and built so cheaply that the integrity of the safety earth cannot be guaranteed. Here in words is the requirement of the safety standard: “In New Zealand (and Australia) the EPOD is a declared article, requiring formal approval by the electricity Regulator before legal sale. In order to gain approval, each model of EPOD is tested and inspected to a specific AS/NZS safety standard that a New Zealand and Australian committee of industry experts and Regulators have produced to ensure that EPODs are safe to use.” If the above is an indication of what is required to pass this standard then it is very poorly written or does not mandate durability. Probably this is in part because the standard does not mandate sufficiently a minimum standard of construction.
As the public at large would not have access to Portable Appliance Testers most people would be unaware that a plugbox which is by all appearances in good condition, could have sustained internal damage that renders the integrity of the safety electrical earth invalid. If that is the case then why are there any requirements for the design of plugs and sockets in relation to the earth pin and earthing as safety mechanisms for appliances? The failure of this plugbox was detected as part of an inspection and testing regime for New Zealand schools that is mandated by the Ministry of Education. It appears there would be a strong case to advise schools that these devices must be considered failure prone and potentially unsafe with a short working life.
