| 摘要 |
<p>In this circuit a heating element (1) is used in an off-peak tariff circuit NT for charging a storage heater and in a high tariff circuit HT for booster heating. To switch the heating element (1) from one circuit to the other a relay with an energising element is fitted in the off-peak tariff circuit; it is designed as a heating cartridge (2) for a heat sensor (3). The latter is connected to an expansion element (4) which is connected to a switching element (5) with two pairs of contacts (6, 7). One pair of contacts (6) is used for closing and opening the off-peak tariff circuit NT and the other pair (7) for opening and closing the high tariff circuit HT. The heating element (1) is only switched into the high tariff circuit HT if the off-peak tariff current NT is blocked, a room thermostat calls for heating, a hand switch is switched to the "On" position and the storage heater is charged only to part of its full rated charge. The circuit prevents triggering of residual current devices when the contact pairs (6, 7) operate. <IMAGE></p> |
