Mitsubishi Electric CNC numerical control system grounding specification

What is the effect of machine tool grounding?

1. Insist that the machine shell and the ground insist on the same voltage.

2. In the event of abnormal external voltage or leakage, the maintenance personnel and the machine tool will not be damaged electrically.

3. Avoid damage to CNC equipment caused by external voltages such as surges.

4. Avoid damage to the PCB circuit board caused by static electricity.

5. Avoid static electricity and electromagnetic waves disturbing CNC equipment.

Mitsubishi Electric CNC numerical control system grounding specification

Mitsubishi Electric CNC numerical control system grounding specification

Machine tool grounding standards and requirements

1. A person with the qualification of "Electrical Engineer" carries out grounding engineering work.

2. For machine tools that are deployed with Mitsubishi Electric's numerical control device, TN-C maintenance and grounding work is usually performed depending on the input voltage.

3. Each machine using Mitsubishi controller needs to be grounded independently, please use conductive concrete with anti-corrosion effect; The wire diameter of the grounding wire is at least 14 mm2 or more, and the grounding impedance of the 400V series shall not exceed 10Ω; Please use a copper rod with a buried depth of more than 1m for the grounding rod, and the grounding wire is indeed grounded and locked.

4. It is advisable to use two DC24V switching power supplies, one for I/O (the amperage is determined according to the number of contacts), and the other for NC (3 amperes) and display (1.5 amperes) to avoid the NC circuit part being affected by the short circuit of the I/O circuit.

5. When using the switching power supply, the DC 24V terminal block 0V, the FG terminal needs to be short-circuited, and the grounding wire should be connected to the common grounding terminal block of the electrical cabinet box after short-circuiting.

6. In accordance with the requirements of the relevant system connection instructions provided by Mitsubishi, the parts that require grounding operations should be connected to the common grounding terminal block of the machine as required, and the common grounding plate with strong and weak electricity should be separated.

7. When using personal computers for DNC/network connection, the power supply of personal computers should use single-phase three-pin sockets, and the shell of the computer host must be grounded with the CNC machine; At the same time, it is proposed to add an optically isolated maintainer.

(1) The computer side must be fixed on the metal shell of the computer with wire lugs, and ensure that the fastening and touch are excellent

(2) The grounding side should be co-ground with the machine tool. Please use a copper grounding rod, if you need to drive it more than 1 meter into the ground, the contact point is excellent and tightened

(3) It is required that the power socket connected to the PC should be equipped with a double-pole double-throw switch type

8. Each machine tool is grounded independently, and when using the stabilized power supply, please ground the stabilized power supply alone.

The strong current plate and voltage regulator of the machine tool enter the strong surge disturbance from the power line in the state of no grounding, because it passes through the unspecified path of the machine tool strong electric plate, and the possibility of problems in polymorphic machines such as CNC units and drive units will be very high.

Mitsubishi Electric CNC numerical control system grounding specification

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