A major player in the EVSE market has kindly consented to provide some technical training for the electrical installation tutors at a training centre where I often tutor part-time. I imagine it is not entirely motivated by altruistic considerations but at least it gives an opportunity for the tutors and myself to get some kind of grasp on the various products on offer and where this particular manufacturer sees the direction of travel for EVSE. I am already aware that the company is moving away from products that rely on the installation of earth electrodes in PME situations and are placing considerable focus on load management. Is there any particular question that you would ask them given the opportunity?
Going back to the OP, we have another Unicorn device here. If we have no performance standard, or one which has not been verified by disinterested parties, we have another problem looming. The AFDD has this problem, and this idea is the same. Detecting that a CNE connection has failed is very difficult because there is no reference potential available, and using a TT type connection as reference has many problems which we have discussed many times. IF the supply is 3 phase, we may use the 3 phase/neutral voltages to recognise a break under some fairly ideal conditions, but load power factors and powers may seriously sway the results so as to make them unreliable. With a single phase supply there is no isolated Earth reference available, and thus it is probably impossible to detect a CNE break. If someone comes up with a non-TT method I would be interested to analyse it fully and the Patent application would be unlikely to succeed if it could not be shown to work under any possible conditions, by demonstration.
Going back to the OP, we have another Unicorn device here. If we have no performance standard, or one which has not been verified by disinterested parties, we have another problem looming. The AFDD has this problem, and this idea is the same. Detecting that a CNE connection has failed is very difficult because there is no reference potential available, and using a TT type connection as reference has many problems which we have discussed many times. IF the supply is 3 phase, we may use the 3 phase/neutral voltages to recognise a break under some fairly ideal conditions, but load power factors and powers may seriously sway the results so as to make them unreliable. With a single phase supply there is no isolated Earth reference available, and thus it is probably impossible to detect a CNE break. If someone comes up with a non-TT method I would be interested to analyse it fully and the Patent application would be unlikely to succeed if it could not be shown to work under any possible conditions, by demonstration.
