The purpose of the distribution box
Facilitate the management, when a circuit failure is conducive to maintenance. Distribution boxes and distribution cabinets distribution panels distribution vouchers, etc., is the centralized installation of switches, meters and other equipment sets.
Commonly used distribution box has a wooden and iron plate system of two kinds, now where the electricity consumption are quite large, so it is still iron with more. The purpose of the distribution box: of course, is convenient to stop, send power, play the role of measuring and judgment stop, send power.
Distribution box composition
Mainly divided into two parts
One is a complete set of components, that is, the distribution box shell and its related accessories.
The second is the electrical components and related accessories, that is, the air switch and its required accessories.
I, circuit breaker
Circuit breaker: both switch, is the main components of the distribution cabinet, commonly used air switch. Leakage switch. Dual power automatic transfer switch
1, air switch:
A, the concept of air switch:
Air switch is also known as the air circuit breaker, in the circuit for the connection, disconnection and carrying rated operating current and short circuit, overload, and other fault currents, and can be in the line and the load occurs in the event of an overload, short-circuit, under-voltage and other conditions, the rapid breaking of the circuit, for reliable protection.
Circuit breaker movable and static contacts and contact bar design varied, but improve the breaking capacity of the circuit breaker is the main purpose. At present, the use of certain contact structure, limit the breaking short circuit current peak current limiting principle, to improve the breaking capacity of the circuit breaker has an obvious role, and is widely used.
B, the working principle of the air switch:
Automatic air switch, also known as low-voltage circuit breaker, can be used to connect and break the load circuit, can also be used to control infrequent starting of the motor. Its function is equivalent to the gate switch, overcurrent relay, loss of voltage relay, thermal relay and leakage protector and other electrical appliances part or all of the function of the sum, is a low-voltage distribution network in an important protection appliances.
Automatic air switches have a variety of protection functions (overload, short-circuit, undervoltage protection, etc.), adjustable action value, high breaking capacity, easy to operate, safe and other advantages, so it is now widely used.
2, leakage protection switch:
A, leakage protection switch concept:
both with leakage protection, people touching the charged body will be tripped to ensure personal safety, is the main function of the leakage protector; electrical equipment, if the insulation is bad leakage to the shell, the leakage protector will also be tripped to avoid the human body touching the electric shock. At the same time with current interruption function, overload protection and short circuit protection.
B, leakage protection switch principle of operation:
Leakage protector working principle diagram. LH for the zero sequence current transformer, which consists of PoMo alloy as the material of the iron core, and winding in the toroidal core of the secondary coil composed of detecting elements. The power supply phase and neutral wires pass through the circular hole to become the primary coil of the zero sequence transformer. The rear outlet of the transformer is the protection range.
C, the role of leakage protection switch:
(1), when the electrical equipment or line leakage or ground faults, can be in the person has not touched before the power cut off.
(2), when the human body touches the electrified object, can cut off the power supply in 011s, thus reducing the degree of current damage to the human body.
(3), can prevent fire accidents caused by leakage.
3, dual power automatic transfer switch:
Concept: dual power automatic transfer switch for the power supply two choose an automatic switching system, the first road failure dual power automatic transfer switch automatically switch to the second road to the load power supply, the second road failure, dual power automatic transfer switch automatically switch to the first road to the load power supply.
Suitable for UPS-UPS, UPS-generator, UPS-utility, utility-utility and any other two power supply without power conversion.