China Nanfeng Electric


How to wire the DC contactor

The DC contactor is an indispensable electrical component in the circuit. For people who rarely touch it for the first time, they don’t know how to wire it. Let’s take a look at how the DC contactor is wired. of.

First of all, we need to understand what a DC contactor is. DC contactor refers to a contactor used in the DC circuit, mainly used to control the DC circuit (main circuit, control circuit, excitation circuit, etc.). The iron core of the DC contactor is different from the AC contactor, it has no eddy current, so it is generally made of mild steel or industrial pure iron to make a round shape. Since the attracting coil of the DC contactor is energized with DC, there is no impulsive starting current and no violent impact of the iron core. Therefore, it has a long life and is suitable for frequent start and stop occasions.

DC contactor

The three main contact points are all normally open, and the auxiliary contacts are normally open or normally closed, and also normally open and normally closed.

Normally open normally closed

The O in the normally open contact NO means the abbreviation of OPEN in English, meaning open; the C in the normally closed point NC means CLOSE, which means closed.
And what people say is normally open and normally closed when there is no electricity.

2 groups of normally open 2 groups of normally closed

Marked with NC and NO, 2 groups of normally open and 2 groups of normally closed DC contactors.

Regularity of normally open and normally closed serial numbers

Three-phase five-wire group out

The three-phase five-wire terminal group outlet terminal is very easy to distinguish, the left and right correspond to the diligent downward movement, the three groups of main contact points control the conduction of the main route, and the auxiliary contact NC and the solenoid A1, A2 on the side are connected to the control circuit.

Solenoid coil A1 and A2

The solenoid coils have different operating voltages. Some DC contactors have two A2s for better wiring, one for each of the front, rear, left, and right. The two A2s are internally connected.

For the wiring of the DC contactor, there are two basic power circuits, one for locking and the other for self-locking interlock.

Self-locking circuit

The key point of locking, after the electromagnetic coil is closed, the power supply system is kept locked according to the normal open point of the DC contactor itself. The knob switch for locking is a self-resetting power switch.

Self-locking interlocking power supply circuit

The most classic and best-used self-locking interlocking power supply circuit that controls the forward and reverse rotation of the motor. At the time of specific wiring, it is best to self-lock and interlock the SB1 and SB22 knob switches.

Understand these two basic power circuits, and you will get started. In fact, in this self-locking interlock power circuit, KM1 and KM2 are also locked. Other complicated power circuits will also use self-locking interlock. Most of them are properly using the normally open and normally closed auxiliary contacts of the DC contactor to maintain various functions.

Company Profile

Zhejiang Nanfeng Electric Co., Ltd. is a company. With DC contactor as the leading factor, it integrates production, R & D, manufacturing anAn enterprise that can be integrated. Our company is specialized in producing medium load and heavy load DC contactor is suitable for electric forklifts, battery cars, tractors, and excavating. Machine, automobile air conditioner, communication power supply, uninterrupted power supply, electroplating power supply, etc. system The switch control of the integrated electronic control circuit has the advantages of small volume and large load capacity.  Long service life, simple maintenance, wide application range, and well received by users. Welcome.

TEL: +86-577-62797256 62776658


Hot News
The structure and working principle of DC contactor
The structure and working principle of DC contactor

Civil melting contactors are divided into AC contactors (voltage AC) a

The working principle difference between DC contactor and AC contactor
The working principle difference between DC contactor and AC contactor

Depending on the application situation, the choice of AC or DC depen

What can be caused by contactor failure ?
What can be caused by contactor failure ?

The contactor is used in our daily work to control whether the equip

Recommend Products