The electric control box contains one or more low-voltage switchgear and related control, measurement, signal, protection, regulation and other equipment, and is completely assembled with structural components by the manufacturer.
1. Classification of electric control boxes
1.1 According to the adaptability of the electric control box to the cold storage
High temperature storage
Medium and low temperature refrigerators and freezers
1.2 According to the adaptability of the electric control box to the compressor
Suitable for scroll air-cooled compressors
Suitable for piston air-cooled compressors
Water-cooled unit electric control box
2. Wiring of electric control box
2.1 Wiring sequence
After everything is ready, start wiring. According to the schematic diagram, the wiring of the main circuit should be completed first, and then the control circuit and signal lines should be connected in turn.
2.2 Paying off
When laying out the wire, the material must be blanked according to the actual length. The movable wire harness should consider the length required at the maximum limit position. When paying out the wire, try to use short and zero wire ends to avoid waste; secondary wires are not allowed to have intermediate joints, strong tensile wires and wires. If the insulation is damaged, the wire arrangement should minimize bending and crossing. When bending, the bending radius should not be less than 3 times the outer diameter of the wire and be bent into an arc. When the wires cross, a few wires should span multiple wires The principle is that the thin wire crosses the thick wire; when wiring, each wire should be straightened, and the line should be straight and neat, with a beautiful style; when the wire passes through the metal plate hole, it must be covered with a suitable protective material on the metal plate hole , such as a rubber retainer; the wire harness is wrapped with a flame-retardant winding tube. In order to meet the heat dissipation requirements during conduction, the winding tube should have a gap of 3 to 10 mm for each round of winding. At the same time, it can also be wound in sections. ~180mm, the winding length is 100mm, and the segmented wiring harness should be neatly segmented, no unevenness is allowed, and the wires should run in the wiring groove.
2.3 Compression of terminal
The wires pass through the wiring head, wiring and external components, and then close the circuit breaker to check whether each circuit is working normally. Only when all the circuits are working normally can the next process be transferred. After the test, the wiring slot and terminal cover should be Reset the cover in time, and the circuit breaker and air switch in the electric control box should be kept in the off state.
3. Test of electric control box
3.1 The wiring outside the panel should be protected by appropriate methods, such as hoses, steel pipes, etc. And the wiring should go where the machine tool is not easily damaged.
3.2 The connection lines or power lines between the machine tools outside the panel must be placed in the bridge frame, which is supported by the base and does not touch the ground!
3.3 The piping outside the panel should be unified horizontally and vertically.
3.4 For the connection of heating equipment such as packaging machines, the wiring cannot be located near the heating part. The wiring is carried out in the connection box with a terminal block. The heater connection uses glass and pottery tube wires, and flammable wires cannot be used.
3.5 All wire connections outside the panel must be carried out in the connection box, and there should be no joints in the middle of the wires.
3.6 The protection level of all connection boxes (relay boxes) and wire entrances outside the panel must be above IP55.
3.7 At most two wires can be connected to the same terminal of the relay terminal block, if there are more than 3 wires, please install another terminal block.
3.8 If the wiring of the sensor is carried out in a place that is easy to be hit, a hose should be used for protection, and the hose should be placed on the root of the sensor as much as possible.