This standard applies to electrothermal equipment with one or more electron guns (hereinafter referred to as electron beam electrothermal equipment), and also applies to high-voltage power supplies for electron guns. This standard, to the extent it is applicable, also applies to devices with glow discharge heating systems. GB 5959.7-1987 Safety of Electric Heating Equipment Part 7 Special Requirements for Electric Heating Equipment with Electron Guns GB5959.7-1987 Standard download and decompression password: www.bzxz.net

1 Fuze
National Standard of the People's Republic of China
Safety of Electric Heating Equipment Part 7
Special Requirements for Electric Heating Equipment with Electron Guns
Safety in electroheat installationsPart 7, Particular requirements for installations with electron guns (hereinafter referred to as electron beam electric heating equipment), also suitable for high-voltage power supply of electron gun.
This standard, to the extent it is applicable, also applies to devices with glow discharge heating systems. 1.2 In addition to meeting this standard, electron beam electric heating equipment should also meet the provisions of GB5959.1 "General Requirements for the Safety of Electric Heating Equipment Part 1".
1.3 This standard is equivalent to the international standard IEC519-7 "Safety of Electric Heating Equipment Part 7 Special Requirements for Electric Heating Equipment with Electron Guns" 1983 first edition (referred to as IEC519-5 in this standard). 2 Terminology
The definitions of terms used in this standard are consistent with the chapters of GB2900 "Electrical Terminology", especially the chapter GB2900.23 "Electrical Terminology Industrial Electric Heating Equipment".
3 Installation of high-voltage feed cable with electron gun
3.1 The high-voltage feed cable should be well insulated and take effective protective measures to avoid mechanical damage. 3.2 When the high-voltage feed cable is laid in a conduit or hose, no other cables should be placed in the pipe except the loop conductor. Each electron gun should have its own conduit or hose. 3.3 If the high-voltage feed cable is located in a conduit or hose, the conduit or hose should extend into the high-voltage end junction box. 3.4 If the high-voltage feeder cable is mechanically and electrically protected, the high-voltage feeder cable may be laid in a cable trench or trough together with the low-voltage cable, but the cable trench or cable trough shall not be considered to be for protection. 3.5 From a safety perspective, each electron gun should be equipped with a loop wire. The cross-sectional area of ??the loop wire depends on the load current of the electron gun, but should not be less than 6mm2 (copper wire). The return conductor should have good resistance. For some special electron guns, if it is necessary to use copper loop wires with a cross-sectional area less than 6mm2, special care should be taken during installation and mechanical protection should be added. The cross-sectional area should be at least equal to the conductive cross-sectional area of ??the feed cable. All circuit wires should be checked frequently to prevent possible accidents, such as checking for loose connectors, broken wires, and loose ends. bzxz.net
The circuit wires can be installed without insulation.
The charge or its bracket should be connected to the positive pole of the high-voltage power supply. The connection requirements are the same as the requirements for the electron gun loop wire described in the previous article. The National Machinery Industry Commission approved on 1987-03-23 ??and implemented on 1988-01-01| |tt||GB5959.7-87
Exactly the same. If more than one electron gun heats the same charge, and a satisfactory conductive connection cannot be established between the charge and the electron gun, the cross-sectional area of ??the loop conductor between the charge and the high-voltage power supply should be increased to be equivalent to the total load current. The voltage drop across the entire loop conductor should not exceed 1.5V at rated current. The return conductor between the electron gun and the high-voltage power supply should be installed together with its feed cable. There should be no joints in the loop conductors between the furnace charge and the high-voltage power supply, and the path should be as short as possible. Note: ① Each device should have at least two loop wires, so that even if one loop wire fails, safety can still be ensured. The specific arrangement of the loop wires depends on the electrical connection between the electron gun chamber and the vacuum chamber and the number of electron guns. ② In electron beam electrothermal equipment, the loop current flows through the shell and frame of each chamber of the equipment 4 Mobile grounding device
4.1 After cutting off the high-voltage power supply and opening the door of the electron gun cover, during contact work it is usually Before removing live parts, any residual charge must be removed with a portable grounding device. The design of the mobile grounding device used should be pre-approved. A portable grounding device should also be placed close to the high-voltage power source and placed in an easily visible location. 4.2 The very flexible grounding conductor of the mobile grounding device should be permanently fixed to its grounding point (circuit conductor). The ground connection point should be located in an easily visible location so that it can be easily inspected by the operator. 5 Minimum distance between exposed high-voltage parts
It is not necessary to comply with the safety clearances applicable to high-voltage devices for electron guns and their power supplies, because they work in dry, clean rooms. These conditions of use should be stated in the manufacturer's installation instructions. 6X-ray and ultraviolet radiation
Devices with electron guns shall be designed and installed so that the operator is protected from any harmful radiation from X-rays and ultraviolet rays while working. The amount of radiation shall not exceed the provisions of relevant standards. The amount of X-ray radiation shall comply with the provisions of GB4792 "Basic Standard for Radiation Health Protection".
7 nameplate
The nameplate of each electron beam electric heating equipment should contain the following content: 8.
b.
c
Equipment model and name ;
Rated input voltage and frequency;
Rated apparent input power, kVA;
Rated high voltage, kV;
d.
e.| |tt||Circuit diagram number;
f.Environment type;
g.
Factory number;
h.
Year of manufacture;|| tt||Manufacturer name.
i.
8 Safety interlock device
The safety interlock device of electron beam electric heating equipment should be safe and reliable to ensure that workers can only operate when the high-voltage power supply has been disconnected and the capacitor has The gun body in the electron gun cover can only be touched when there is a discharge. These safety interlocking devices shall be mechanically and/or electrically operated. 9 Vacuum system
9.1 The air extraction system should have sufficient air extraction capacity, and protective measures should be taken to protect workers from harmful radiation. 9:2 The moving parts of the vacuum pump, such as belts, pulleys, etc., should be equipped with protective facilities to avoid accidental contact. GB5959.7-87
9.3 If the vacuum chamber is large enough for people to enter, protective measures should be taken to avoid vacuuming when people are in the vacuum chamber. 9.4 Before the vacuum degree of the vacuum chamber reaches the working vacuum degree, the vacuum chamber should be The high-voltage power supply of the electron gun cannot be supplied. If there are special requirements or safety factors are considered, the high-voltage power supply should be cut off when the working vacuum is lower than the set value, but the safety interlock requirements in Chapter 8 should still be complied with.
10 Cooling water
For some key components (such as crucibles) that use water cooling, appropriate monitoring devices should be provided in accordance with GB5959.1 11 High-voltage power supply
The high-voltage power supply should have settings High-voltage power supply with adjustable overcurrent protection and overvoltage protection devices should not be affected by grid overvoltage. For high-voltage power supplies that use thyristors as rectifier components, protective measures should also be taken to protect workers from harmful radiation from X-rays. Additional Note:
This standard is under the jurisdiction of Xi'an Electric Furnace Research Institute. This standard is drafted by Xi'an Electric Furnace Research Institute. The main drafters of this standard are Ge Huashan and Cai Jinhe.
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