| 摘要 |
A prepayment electrical supply system comprises means of detecting the existence of electricity consumption from the time of activating the electrical supply system and means suitable for indicating an anomaly when no electricity consumption is detected. The system also includes means 11 to indicate the presence of voltage. The indication of an anomaly, when no electricity consumption is detected, may be reset when electricity consumption is detected and the means of electricity consumption detection may involve current measuring means. The system may also include means to detect the balance of credit against the value of electricity supplied and if a negative balance occurs or exceeds a certain threshold, a further indication of possible fraud may be provided. The system can detect and indicate by means of a display 8 the possible use of bypass arrangements L3, L4 around the means of measurement 5 and / or the means of isolation 2. |
