| 摘要 |
The group supply (P,N) is received by a 3OA 4-pole main switch (D). If 1-phase, the line poles (P1,P2,P3) operate in parallel. A microprocessor-based controller (1), with current sensor input (2,3,4), has memory (6) and display (7) facilities for regulating prepayment arrangements. Current-limiting, overcurrent and residual current protection are installed, also a pay-in register key-pad (8). Consumers (U11-U14; U21-U24; U31-U34) allotted to each distributor (P11/N11;P14/N14, etc.) each have a main switch (D11-D14;D21-D24;D31-D34) with overcurrent and residual protection. Typically, these trip if more than 2.5A is drawn and the main group switch if more than 10A. All consumers can lose supply if one illegally exceeds his limit. Satisfactory operation requires one consumer to accept responsibility for identifying offenders, settling disputes, maintaining prepayment, etc. |
