The wiring instrument is equipped with two sets of contact wiring terminals as shown in the figure below. A1, B1, C1, A2, B2, C2, N1 are grouped together (used to test the main contact time). A3, B3, C3, A4, B4, C4, N2 are grouped together and can measure six auxiliary contacts or six main contacts. When A3 to C4 are set as auxiliary contacts, the fitting time of the A-phase main and auxiliary contacts is A3-A1, A4-A1 (similarly, the fitting time of the B and C phases is B3-B1, B4-B1, C3-C1, C4-C1), and the common terminals N1 and N2 are used separately.
Attachment: Definition of normally open contact: A contact that is in a disconnected state under normal conditions (circuit breaker opening) is called a normally open contact. When the coil is energized, the normally open contact will close, while the normally closed contact will open.
