| 摘要 |
<p>A break of card-type electric meter consists of two cases, in which one is a neutral wire case and the other is a phase wire case. The phase wire case is a standard micro-breaker. The neutral wire case includes contact device, electromagnetic trip device, thermosensitive ceramic element, control circuit sequentially, in which control signal terminal connects with control circuit, the up and the down terminals connect the contact device respectively. Between the neutral wire case and the phase wire case there is a secondary contact which operates together with contact devices in two cases. The thermosensitive ceramic element is an element of negative temperature coefficient. The electromagnetic tip device includes a relay, in which a secondary contact and contact devices in two cases are three normally closed contacts of this relay.</p> |
