Before understanding the self-locking connection of the Solar Photovoltaic System Circuit Breaker, we must first understand the principle of contactors and normally open and normally closed contacts. If we don’t know this, we still don’t know anything about wiring. First, explain the principle and structure of the contactor.
The 380V AC contactor has three main contacts, namely the power inlet and the load outlet. The incoming lines are three-phase live lines L1, L2 and L3, and the outgoing lines are T 1T2 and T3 respectively. The incoming and outgoing wires of the main contactor correspond to T1, L2 corresponds to T2, and L3 corresponds to T3. When the contactor is not pulled in, the main contact is usually open.
The Solar Photovoltaic System Circuit Breaker also has a normally open auxiliary contact, which is the fourth contactor contact on the right, which also corresponds from top to bottom. When the Solar Photovoltaic System Circuit Breaker is not pulled in, it is always in the normally open state. The auxiliary contact is used to control the contactor through the auxiliary button, and the main contact is used to control the load side, so it is divided into the main contact and the auxiliary contact.
If you want the contactor to be sucked in, the contactor will only be sucked in when the contactor coil is energized. The coil voltage of the AC contactor is 220 volts and 380 volts. The two contacts of the voltage connection are A1 and A2, which means that as long as the coils A1 and A2 are energized, when the voltage is 220 volts or 380 volts, the contactor will pull in.
The coil is located in the middle of the back of the Solar Photovoltaic System Circuit Breaker, and its function is to generate electromagnetism after the coil is energized, and there is an armature in the middle of the front of the contactor. After the armature is energized to generate electromagnetic, it starts to attract the front armature, and the front armature pushes the upper and lower contacts of the main and auxiliary contacts of the contactor, so that the normally open contacts of the contactor become normally closed contacts, and the normally closed contacts become normally open Contact.
We use a Solar Photovoltaic System Circuit Breakerto lock our main contacts and auxiliary contacts are normally open contacts, so the contacts of the contactor become normally closed contacts after the contactor is pulled in, that is, the four on the contactor The contacts communicate with the four contacts below the contactor. The load end of the rear contactor will have electricity, and the load end will start to run. When the coil is cut off, no electromagnetism is generated, so the armature will not be attracted, and there is a spring between the coil and the armature. It will automatically bounce the coil and armature back to the original position, so that the normally closed state of the contactor is restored to the original normally open state, the upper and lower contacts of the Solar Photovoltaic System Circuit Breaker are disconnected, and the load stops running.