GB 5959.9-2008Safety in electro-heat installations -- Part 9: Particular requirements for high-frequency dielectric heating installations (English PDF)

3.1

It means consisting of a dielectric and the dielectric heating applicator generator, high frequency transmission line (if any).

3.2 Or by the heating of the capacitor fixing and positioning system with a working electrode, an impedance matching circuit (if it is not disposed in the generator), the need

Protection and shielding means and transfer means, the supply and ventilation thereof.

4.1 Overview

Dielectric heating generator comprising.

a) a portion of the frequency components of the power supply and distribution required;

b) a rectifier section, which typically includes the commercial frequency current into a high voltage direct current component;

c) oscillator section, and which comprises generating high frequency energy necessary for matching element (oscillator section housed within a high frequency shield to reduce radiation);

d) control and monitoring system, which comprises a program controller for interlocking the overload safety device and a switching means and monitoring Device.

4.2 Pairs of direct contact with the protective

4.2.1 General Protection

In addition to dielectric heating generator output terminal, all the live parts to be provided in one or more adequate for protection against direct contact With the housing.

4.2.2 Protective measures close to the second section of the charging voltage portion

For accessing the second section of the door voltage (up to 1500V 1000V AC or smoothed DC) charging section and/or removable cover Plate, should be provided with a key to open the door or configuration, when the door is open or remove the cover interlock can cut off electrical power.

Rarely open to the removable cover should be fastened with screws secure the safety screw without tools or with standard tools that they can not Remove the.

4.2.3 Proximity third segment voltage charging portion safeguards

Used for access to the third segment voltage (over 1500V 1000V AC or smoothed DC) portion of the charging door and/or removable cover Plate, mechanical interlock shall be provided with a power measures to prevent the electrode portion closer to the charging voltage is removed prior to, or at the same time an electrical configuration of the door Gas interlock and mechanical locks.

Rarely open to the removable cover should be fastened with screws secure the safety screw without tools or with standard tools that they can not Remove the.

4.2.4 Protective measures in the proximity of the high-frequency voltage charging section

In the case where only the live parts may be close at a high frequency voltage (not close in a 50Hz/60Hz frequency voltage of lower frequency, such as Live parts), should take the following precautions.

Except when the foreign matter does not enter the high-frequency component while in contact with the protective housing of the door or the protective cover or housing to provide comprehensive and effective An outer protection, the protective shell of the movable cover or door openings to be provided and reliability can not be reset or non-reset of the safety switch Interlock means to ensure that when a high frequency voltage is not applied when the door is open or remove the cover plate.

Few of the open cover removably screwing security applications, the security screw with standard tools without tools or from outside it is not They were relieved of.

4.2.5 Warning labels

It should set the necessary warning signs.

NOTE: In some countries, the need to set up warning signs to inform non-ionizing radiation with a marker.

4.3 Other protective measures

4.3.1 Protection device should have the following means.

a) should be provided with one or more means to protect the under abnormal operating conditions (e.g., during the overload condition) it from damage Means;

b) if necessary, be provided with one or more of the present apparatus so as to protect the device from interference of other devices;

c) if necessary, it is provided with one or more means of the present apparatus so as to protect against interference autogenous.

4.3.2 If necessary, each of the protection device shall be jointly overtemperature protection.

4.3.3 shall take appropriate measures to reduce the induced voltage or induced current so that it meets safety standards.

4.3.4 All armored cable and the metal feed pipe, in through the high-voltage circuit contains a voltage belonging to the third segment of the housing, they should be Grounded through the housing.

4.3.5 DC power and 50Hz/60Hz frequency AC power station apparatus, the grounding should meet the requirements of GB 5959.1-2005.

Means for transmitting high-frequency power apparatus should be protected to ensure that the voltage at the contacts where the operator is allowed value, for example with a ground The shield and/or an operator located at the ground.

4.4 Temperature Rise - Fire

4.4.1 dielectric heating generator and a rectifier, the circuit should be arranged so that they are subjected to neither high temperature nor in the cabinet housing so that they The temperature generated electrical device generally exceeds the allowed values.

4.4.2 material for the high-frequency voltage component to be free of any component will produce sustained combustion.

4.4.3 When the temperature rise within the cooling circuit fault of the generator will exceed the allowable value, the monitoring device should be provided for the power supply of the cutting device Or take other measures to ensure safety.

4.5 Clearance and creepage distances

A high frequency device used in the air gap and creepage distance are not necessarily identical 50Hz/60Hz frequency and means.

When small air gaps and creepage distances (e.g., high-frequency circuits), measures should be taken to prevent arcing to ensure safety.

4.6 Internal electrical connections

4.6.1 high-frequency current conductor and the connection means should be non-ferromagnetic material, it should also cover non-ferromagnetic material.

4.6.2 should be protected all the low frequency circuit, in order from the effects of high frequency of, for example, configure one or more high-frequency filter.

4.7 Capacitor

4.7.1 Unless the capacitor device and other electrical equipment in direct contact with the discharge path and the discharge path does not access the disconnecting Off fuse or the series capacitor, to ensure safety, the capacitor device belonging to respond to the second and third segments direct voltage even when necessary Contact discharge device.

Note 1. discharge means can not be used a short-circuit between the capacitor and staff to ground before the respective terminal contact of the capacitor.

Note 2. IEC 60204-12) 6.2.4 frequency of the power supply and control circuit measures the residual voltage protection means carries electrical charge of equal or greater than 60µC container.

Note 3. The high-voltage capacitor circuit in the vast majority of the charge carried by much less than 60µC, according to the article discharge device may be omitted.

Note 4. high voltage power supply filter capacitor some charges may exceed this value, then the article precautions apply.

2) Description adopt standard. GB 5226.1-2002 Safety of machinery Electrical Equipment Part 1: Common technical (current valid version) (IEC 60204-1:2000, IDT).

When using high-voltage power 4.7.2 LC filter when the energy conversion element (such as a tube or a semiconductor device), a vibrator should be provided if necessary, Oscillation damping means to prevent over-voltage disconnect the circuit exceed the allowable value.

4.8 Cooling

4.8.1 water cooling members, appropriate measures should be taken to limit the electrolytic corrosion interfere with normal operation. For this reason, the manufacturer should be provided with means Suitable instructions for use.

4.8.2 Soft water and its layout should make the leak current does not exceed safe levels.

NOTE: In the cooling system should try to avoid the formation of bubbles. Hose fittings require special attention.

4.8.3 In the water-cooled conductor passing high-frequency current, to avoid water condensation.

4.8.4 of forced air-cooled medium heat generator, precautions should be taken to prevent and reduce the deposition of dust due to the safety of the operation.

4.9 Overload

4.9.1 circuits and components for dielectric heating generator, if the temperature exceeds the allowable value, should provide thermal overload protection.

4.9.2 short-circuit may occur in all parts of the device caused by the overload protection should be provided.

4.9.3 If necessary, the medium is heated generator should be provided with a program control device, in order to ensure personal power down under abnormal operating conditions, and Safety device.

4.9.4 If the charge processing device for heating the medium located outside the generator should be provided with a remote connection terminal, should be provided for at least Operation "Emergency Stop" connected terminal device. RFI suppression 4.10

Note: the provisions concerning radio frequency disturbance limits in the CISPR11.

5.2 Flammable materials processing

In dealing with flammable materials, should take special precautions.

5.3 Pairs indirect contact protection

High-frequency radiation not induced any case when the operator endanger personal contact therewith on the outside of the shield member or housing Security of voltage or current.

Heating the capacitor or only the working electrode is typically a high frequency voltage without frequency 50Hz/60Hz or DC voltage component (thermal plastic Preventing burn-off means except when a low pressure). When a failure (insulation breakdown) occurs, 50Hz/60Hz or DC voltage may occur in the electrical heating The container or on the working electrode. Accordingly, the adoption of an inductor (if no such inductance in the actual circuit) or the electrodes of the capacitor Ground.

5.4 Other protective measures

5.4.1 normal operation is unlikely to occur flashover should be given adequate attention.

Note: In some cases, when a high-frequency electrode voltage exceeding 10kV magnitude, the arc may be generated (flying in a space around the heating electrode of the capacitor arc). This arc power capacity of 0.5kW of magnitude, typically less than the high frequency useful power. Thus, the arc does not cause the overcurrent device operation. for The elimination of the arc, it may be necessary to manually cut off and close the high frequency voltage.

5.4.2 Design of the insulating support member should take full account of its tensile and compressive strength as well as temperature and electrical voltage withstanding property.

5.4.3 shall mechanical parts in high-frequency electromagnetic field to be under protection, the induced current generated neither they nor damage Movies Ring their normal function.

5.4.4 Commutation overflowing liquid material for high-frequency treatment apparatus suitable size should be provided isopipe.

5.4.5 is exposed to the high frequency electromagnetic field should be appropriately shielded electrical conduits.

5.4.6 All metal parts should be applied to an internal charge antistatic protection.

5.4.7 device located outside the shielding metal member was appropriately combined together as far as possible, to prevent local excessive temperature rise and/or too strong High-frequency interference.

High-frequency radiation in the place in which the strength of the operator 5.4.8 shall comply with the national country of the apparatus used (see GB 5959.1-2005)

Note: The circumstances of RF harassment, see 4.10. Test 6 protective measures

6.1 Test procedure should be considered and should be checked for all protective measures in each case to ensure the safety of the operator.

6.2 pairs accessible during normal use high-frequency circuit, the temperature should not exceed 150 °C. This can be an appropriate way to check.

6.3 should be accessible or heating the working electrode of the capacitor short circuit. Dielectric heating power generator is set at a maximum value, Or operator of the apparatus should be no harm or danger (e.g. […]