TNAG-0767-FCO40-971-Supplies-of-electrical-power-for-Hong-Kong-Castle-Peak-power-1978 — Page 126

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XCR (78)129

of the range would be outside the tolerance for much existing equipment. Even if 6% were adopted, the higher end of the range would be 244 volts, which would mean that equipment designed for 200 volts would be operating at + 22% over voltage;

(c) for industrial consumers: that many of the

countries constituting their main source of supply have not adopted 230 volts yet;

(d) the higher voltage would increase the risk of

faults in the case of unsatisfactory wiring.

In any case, as a voltage of 230 volts is associated with a tolerance of 10%, its lower bracket at 207 volts is also the lower bracket of 220 volts ± 6%. Thus equipment manufactured for 230 volts should operate adequately at 220 volts. And a decision to go only to 220 volts for the time being would not preclude a move to 230 volts later.

Compensation

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In Britain, compensation was paid to those caught with unsuitable equipment when supply systems were moved onto a higher voltage. The payment of compensation here would be difficult to administer. Change of voltage would tend to be alleged as the cause for all electrical failures; and it would be difficult to establish what the true causes were. But, more important, if the change in Hong Kong amounts to only 20 volts and is taken in two steps with a five year interval after adequate notice, consumers should have time to adjust to the higher voltage which, after all, is being changed to their advantage.

Proposed change of voltage

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In all the circumstances, it is proposed, in principle, to change the supply voltage from 200 volts single-phase (346 volts three-phase) to 220 volts single-phase (380 volts three-phase). To give consumers time to adapt to the new voltage, it is proposed to introduce it in two stages:

Stage 1 tổ 210 volts on 1st July 1980

Stage 2 to 220 volts on 1st January 1985,

It is further proposed that no compensation be payable in respect of equipment unsuitable for use with the new voltages.

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