Introduction to the starting mode of refrigeration compressor motor

In refrigeration motor equipment, the compressor can be started in different ways according to the size of the current limit. The following describes several boot modes.

1. It can be started by the capacitor starting mode, commonly known as CSIR. After the circuit of the auxiliary winding is connected, the current passes through the electric shock at the top of the starting relay, the starting capacitor, the auxiliary winding and the motor protection device. Another current flows through the main winding and the motor protection. After starting, the contact at the top of the relay is disconnected, and the auxiliary winding stops, no longer working.

Capacitor starting features: small current, simple structure, less than 300w small refrigeration equipment is widely used.

2. Start with resistance. Commonly known as: RSIR. It is a resistance phase starting circuit, which is composed of main winding, auxiliary winding and current relay. The elastic arm closes the auxiliary winding and the motor starts to rotate. With the point attack running at high speed, the current in the main winding quickly begins to drop, the elastic arm begins to open, and the auxiliary winding stops working.

Resistance phase separation start-up features: high current, low torque, resulting in reduced efficiency, used in small power chillers with capillaries.

3. Start with capacitor operation, commonly known as PSC. Capacitor operation mode In starting or running a motor, the same capacitor is connected to the circuit of the auxiliary winding. There is no starting relay in the circuit of this operation mode, and the capacitor is mainly configured according to the rated working condition of the motor. The starting torque of a capacitive running motor is small, but the torque increases as the speed increases. Capacitive running motor has high power, and its load is mainly borne by the main winding and only a small part of the auxiliary winding, so its overload load capacity is small. After increasing the capacitance, the load borne by the auxiliary winding increases and the overload capacity increases. But the capacitor capacity can not be too large, otherwise in no-load and light load energy efficiency ratio will be reduced.

Capacitive and rotary starting characteristics: mainly used in compressors with small starting load torque.

4, capacitor start capacitor operation mode (CSR) CSR circuit has two kinds: (1) with PTC relay; (2) Equipped with voltage relay.

When starting, electricity flows through the auxiliary winding of the starting capacitor PTC relay and the motor protection device (at this time, the running capacitor and the starting capacitor are in parallel); Another current flows through the main winding and the motor protection. After starting, the starting capacitor no longer works due to the action of the PTC relay. The two capacitors operate simultaneously at starting, thus increasing the starting torque.