What are the Components of a Distribution Panel and main usage?

The definition of the Distribution Box

The “distribution box”, also called distribution cabinet, is a general term for the motor control center. The distribution box is a low-voltage power distribution device that assembles with switchgear, measuring instruments, protection appliances, and auxiliary equipment in a closed or semi-closed metal cabinet or on a screen according to electrical wiring requirements.

The main function of the distribution box

The main functions are “power generation”, “transmission”, “transformer”, “distribution”, the first always be power generation, after the step-up transformer, and then the power supply. After the high voltage is changed to high voltage, it is transported to various places, and after the voltage transformer is changed step by step to the voltage we need, and finally to the electric equipment transported through the distribution equipment.

The distribution box is a new type of comprehensive control box that integrates power distribution, measurement, protection, control, and reactive power compensation. Generally, it constitutes a low-voltage distribution box that requires switchgear, measuring instruments, protection appliances and auxiliary equipment to be assembled in a closed or semi-closed metal cabinet or on a screen. In normal operation, the circuits can be connected or disconnected by means of manual or automatic switches.

It is convenient for management and for overhauling in case of faulty. The distribution box and distribution cabinet, distribution board, distribution vouchers, etc., are complete sets of devices such as switches and meters installed centrally.

In common, the distribution box has wood and iron plate system, as the electricity consumption is quite large, so the iron is in much more usage, The purpose of the distribution box: to facilitate the stop, send power, measurement and judgment stop, send power role and so on.

The distribution box is composed of a switch, wire, shell, different distribution boxes, and also its internal structure is different. The main purpose of the distribution box is to modernize the power so that the enterprise’s power centralized and administrator management.

The main parts of the distribution box 

(1) Complete components: i.e., distribution box shell and its related accessories.

(2) Electrical components and related accessories: i.e. air switches and their required accessories.

Second, the cabinet is composed of the following parts:

(1) Circuit Breakers

Circuit breaker: the main component of the distribution cabinet, there are air switches. Leakage switch. Dual power automatic transfer switches are used commonly.

Air switches, also known as air circuit breakers, are used to turn on, off, and carry the rated operating current, short circuit, overload, and other fault currents in a circuit, and are capable of rapidly breaking the circuit for reliable protection in the event of overload, short circuit or under voltage in the circuit and load.

Various types of dynamic and static contacts and contact bars of circuit breakers are designed, but improving the breaking capacity of circuit breakers is the main purpose. At present, the current-limiting principle of using a certain contact structure to limit the peak short-circuit current during braking has an obvious effect on improving the breaking capacity of the circuit breaker, and is widely used.

Principle of operation of air switches.

An automatic air switch, also known as a low-voltage circuit breaker, can be used to turn on and offload circuits, as well as to control motors that start infrequently. Its function is equivalent to the sum of some functions of switches, overcurrent relays, loss-of-voltage relays, thermal relays, and leakage protectors, and it is an important protection appliance in low-voltage power distribution networks.

The automatic air switch is widely used because of its multiple protection functions (overload, short-circuit, under-voltage protection, etc.), adjustable action value, high breaking capacity, easy operation, and safety.

(2) Leakage protection switch

The concept of Leakage protection switch.

The main function of the Leakage Protector is to ensure the safety of the human body by tripping when a person touches a charged device; the Leakage Protector will also trip if the electricity-using equipment is poorly insulated and leaks into the shell to avoid electrocution by human touch. It also has the functions of current interruption, overload protection, and short circuit protection.

Operating principle of the Leakage Protection Switch.

The LH is a zero-sequence current transformer consisting of a Permalloy core and a secondary coil wound on a toroidal core as a detection element. The primary winding of the zero-sequence current transformer is made up of a power phase and neutral conductor through a round hole. The rear exit of the transformer is the protection range.

The function of the Leakage Protection Switch.

(1) When there is a leakage or grounding fault in electrical equipment or wiring, the power can be cut off before a person touches it.

(2) When the human body touches charged objects, it can cut off the power supply within 011s, thus reducing the degree of damage caused by the current to the human body.

(3) It can prevent fire accidents caused by electricity leakage.

(3) Dual power automatic transfer switch

The dual power supply automatic transfer switch is an automatic switching system for the power supply, after the first road failure, the dual power supply automatic transfer switch automatically switches to the second road to supply power to the load, the second road failure, the dual power supply automatic transfer switch automatically switches to the first road to supply power to the load.

In conclusion

Nowadays, we need electrical power in where, and the distribution board is an important part of the electrical system, both in high and low voltage.

Everyone needs to know some basic knowledge to avoid some emergency happened. That was today’s article. Thanks for reading.