GB 5959.3-2008Safety in electro-heat installations -- Part 3: Particular requirements for induction and conduction heating and induction melting installations (English PDF)

Foreword

All technical contents of this section is mandatory.

GB 5959 "electric safety devices" has the following 13 sections.

--- Part 1. General requirements (GB 5959.1-2005, IEC 60519-1:2003, IDT);

--- Part 2. Particular requirements for arc furnace apparatus (GB 5959.2-2008, IEC 60519-4:2006, IDT);

--- Part 3. Particular requirements for induction and conduction heating apparatus and an induction melting apparatus (GB 5959.3-2008, IEC 60519-3:2005, IDT);

--- Part 4. Particular requirements (GB 5959.4-2008, IEC 60519-2:2006, IDT) resistance heating means;

--- Part 41. Particular requirements for resistance heating means for heating and melting glass --- means (GB 5959.41-2004, IEC 60519-21:1998, IDT);

Safety regulations plasma apparatus (GB 5959.5-1991, eqv IEC 60519-5.. 1980) --- first portion 5;

--- Part 6. Safety Specification Industrial microwave heating apparatus (GB 5959.6-2008, IEC 60519-6:2002, IDT);

--- Part 7. Particular requirements for the apparatus having the electron gun (GB 5959.7-2008, IEC 60519-7:2008, IDT);

--- Part 8. Particular requirements for electroslag remelting furnace (GB 5959.8-2007, IEC 60519-8:2005, IDT);

--- Part 9. Particular requirements (GB 5959.9-2008, IEC 60519-9:2005, IDT) high-frequency dielectric heating apparatus;

--- Part 10. for industrial and commercial heating systems special requirements (IEC 60519-10:2005, to be transformed) resistor profiling;

--- Part 11. electromagnetic stirring of the liquid metal, the special requirements of the transport or pouring (GB 5959.11-2000, idt IEC 60519-11:1997);

--- Part 13. Particular requirements for the heating apparatus having an explosive atmosphere (GB 5959.13-2008).

In addition to this standard an outer part 13, are used to develop each of IEC 60519 part "safe heating apparatus" corresponds. This is Part of 3 GB 5959.

This section is equivalent to using IEC 60519-3:2005 "Safety heating means Part 3. induction and conduction heating apparatus and an induction Particular requirements melter "(third edition, English).

For ease of use, for IEC 60519-3:2005, made in this section, the following editorial changes.

--- "This standard" be replaced by "this section";

--- deleted international standards foreword and preface.

This partial replacement GB 5959.3-1988 "safe third portion of the electrothermal device. induction and conduction heating and induction melting apparatus Special requirements "means, as compared with the latter the main technical changes are as follows.

--- Press GB 5959.1-2005, expanding its scope, including not more than 3600V AC or DC voltage to the third section device of.

--- Definition and GB/T 2900.23-2008 "Industrial Electrical heating device term" consistency.

--- in the chapter, deleting "7 of the motor generator inverter unit of formula (variable frequency drive)", and "9 ferromagnetic double frequency" on the other two sections and chapters It relates to the two power related content, such as deleting the original 10.1. Due to technological advances, the two power has been eliminated.

2 Normative references

Terms of the following documents constitute provisions of this section by reference in this part of the GB 5959, dated references, All subsequent amendments (excluding corrections) or revisions do not apply to this section, however, encouraged to reach an agreement under this section Whether the parties to use the latest versions of these files, undated reference documents, the latest versions apply to this section.

GB/T 2900.23-2008 Electrotechnical term industrial heating means (IEC 60050-841:2004, IDT)

GB/T 3984.1-2004 induction heating Power capacitors Part 1: General (IEC 60110-1:1998, IDT)

GB 5959.1-2005 electric safety devices - Part 1: General requirements (IEC 60519-1:2003, IDT)

GB/T 6115.1-2008 Series capacitors for power systems - Part 1: General (IEC 60143-1:2004, MOD)

IEC 60364-4-41:2005 low voltage electrical installations Part 4-41. 1 safety Protection against electric shock)

1) adopt standard conditions. 4-41 GB 16895.21-2004 part Electrical installations of buildings. Protection for safety Protection against electric shock (currently valid version) (IEC 60364-4-41:2001, IDT).

3 Terms and Definitions

GB/T 2900.23-2008 and GB 5959.1-2005 established following terms and definitions apply to this section.

3.2 Current through the resistive heating material to be heated

4 Heating inductor ---

Added to the high power heating inductor disposed about the requirements of the yoke (see 4.1);

Added cooling aspect heating inductor (including spare cooling source) technical requirements (see 4.3, 4.4);

Add the required configuration of the voltage limiting system (see 4.6).

--- 5 capacitor New requirements for discharge capacitors connected in series (see 5.4);

Requirements for liquid cooling of the capacitor to direct reference to the provisions of GB 5959.1-2005 in 6.2.8.

--- 6 frequency power He added the last paragraph, that the design should pay attention to a possible hazard due to the parallel resonance.

--- 7 solid drive Added to the event of failure due to the role of energy storage protection requirements.

--- 9 cable, wires and busbars New requirements for cables, wires and the busbar arrangement (see first paragraph 9.1). Another new action to avoid stray field requirements (see 9.1 third paragraph).

4.2 When the heating member due to wear or a sensor or to meet new production requirements need to be replaced, it should be carried out in accordance with manufacturer's instructions.

4.3 If the heating inductor insufficient cooling effect when danger to personnel or damage to the major components of the apparatus, packets should be sent An alarm signal and automatically cut off the heating power.

4.4 When the forced cooling electric heating device employs its sensors and charge and/or lining and high heat capacity, recommended alternate cooling sources arranged To cool the coil, and the cooling heat transfer means until the materials have been removed and when necessary, the lining has been cooled to a safe temperature.

4.6 Electrical equipment configuration suitable to be pressure-limiting system to prevent heating induction voltage exceeds a limit 3600V AC. In this case Under conditions, the nominal voltage shall be selected on a suitable value below the 3600V AC.

The yoke design should be noted that the risk of excessive heating of the vortex.

5 Capacitor

This chapter is involved in power capacitors. Other capacitors, such as capacitors on a circuit controlled by the GB 5959.1-2005

5.1 pairs of capacitor contactors dangerous after a power failure, it shall take all necessary measures to rapidly discharge.

Warning signs should be provided in a prominent position, note should be discharged before contact capacitor.

5.2 pairs of permanent capacitor connected in parallel with the heating inductor or transformer may be omitted discharge device.

When in parallel to the inductor or transformer may only be disconnected capacitors in case of power failure, the discharge means may be omitted, but requires at break Electrically opening between the switch has sufficient time-lag capacitor discharging it.

If there is danger of DC charging, the discharge device is indispensable.

5.3-load operation capacitors or capacitor via external fuse should be equipped with a discharge device.

5.1 2008.

5.5 Internal series capacitor having a terminal element should be short-circuited before disconnecting.

5.6 capacitor without power control frequency electronic devices should be connected via the protection device. When the internal fuse can protect the external unworthy Device., The capacitors may not be connected via high-frequency protection devices.

5.7, shall be subject to the provisions of GB 5959.1-2005 liquid-cooled capacitor in 6.2.8.

6 Frequency power

And using the power supply to the capacitor and the reactor by a three-phase power to a load way to achieve a balanced three-phase current mains frequency, if the flat The common point of the capacitor and the reactor of the equalizing circuit that phase open contact (e.g., blown fuse or a line contactor failure), will Generating series resonance overvoltage causing compromised.

Measures should be taken off the power for this case, let the power circuit breaker as overvoltage trip.

Three-phase power to the control reactors - balancing circuit capacitor contact, should be designed to ensure that the reactor is connected to a capacitor and a common The contact point in the closing of the closure in advance, and when the off delay trip.

Design should pay attention due to the risk of harmonic parallel resonance current may be absorbed from the power supply system.

6.6.4 Requirements in GB 5959.1-2005 not apply to them, these elements can only withstand liquid cooling rated working pressure, and the joint thereof It should withstand 1.5 times the rated working pressure.

Cause a pressure surge may be considered when the switching valve.

7 Solid drive

7.1 Solid inverter at the input should be protected to prevent the power source side may be generated at the beginning of the transient when the overvoltage, to ensure safety.

7.2 solid drive should be fast acting overvoltage and overcurrent protection.

7.3 additional measures should be taken to avoid because of the rapid changes in load power and danger of transient voltage.

7.4 should take appropriate measures to avoid causing harm to workers due to the role of energy storage in the event of failure.

8 Switching means

8.1 no-load switching device should be designed into the drive, the reactance elements (transformers and reactors) and temporal characteristics of the capacitor.

8.2 Design of the switching devices should consider not only the fundamental component of the current, and harmonic components should be considered may be generated.

8.3 When the load capacitor when switching the switching means or the selector switch embodiment in particular, should consider the following points.

--- When closing, may generate high peak amplitude of high frequency current;

--- When opening, the switching device should be avoided due to the restriking overvoltage reached a dangerous level.

9 Cables, wires and busbars

9.1 cables, wires and the busbar arrangement and size, and should be considered as contained in the current magnitude and frequency, so that the heat does not exceed the allowable value.

Note: value is adapted to the cable carrier frequency (50Hz or 60Hz) of the apparatus are generally not suitable for higher frequencies.

In parallel connection, it should be taken to avoid uneven current distribution due to the phenomenon caused by overheating of individual conductors.

It should be taken to avoid excessive heating of the stray field adjacent structures.

Added to avoid excessive internal overcurrent requirements (see last paragraph 9.3).

10 --- Liquid cooled New requirements "may cause a pressure surge-off valve should be considered" (see paragraph 2 10.3).

Add cooled below the dew point for avoiding requirements (see 10.4).

Deleting the original 12.4, when the article is its own complement of standard adoption in China. The contents of this section has been in the 4.3, 4.4, A. 1.6, A. 2.6 And A. 2.7 respectively mentioned.

--- 13 electric shock protection Deleting the original first paragraph 15.1.3 and 15.2 (content and 9.3 GB 9.2 5959.1-2005 and repeat).

Canceled a maximum contact voltage continuous schedule (Figure), the words "recommended limits are under consideration, should the use of existing national standards Accurate "(see 13.1.1);

Added with the metal of the graft, artificial pacemakers and other personnel protection requirements (see 13.3.1).

Appendix B --- special requirements for induction melting apparatus Deleting the original B. 1.8 and B. 1.9 Emergency furnace tilting mechanism and the hydraulic device disposed on the requirements.

New requirements for the validity of the charge regularly check the grounding electrode [see B. 4g)].

Deleting the original "B.6 thermal protection" (repeat with GB 5959.1-2005 Chapter 13).

This section should be used in conjunction with GB 5959.1-2005. Present as part of the induction heating means and the conductive means of induction melting, and Special requirements, supplemented and refined on the basis of the GB 5959.1-2005. Appendix A and Appendix B of this section is normative.

9.2 If the cables, wires and busbars the use of forced cooling, it shall comply with GB 5959.1-2005 and 6.6.2 of the 6.2.8,6.6.1 Provisions.

9.3 For internal connection lines between classes, such as the inverter, a transformer, a capacitor, a switching device, and a contact system of the sensor member, if this These lines are connected to ground short circuit-proof and anti-leakage, overcurrent protection apparatus of the device alone can be omitted.

NOTE: If the cable conductor and the single-core wires hard to maintain sufficient clearance between each other or adopt an insulating gasket, or the conductor laid in the respective insulating ducts, or Using a design has been provided a short-circuit protection of wires or cables, thus preventing them with each other (including the ground portion) of the contact, then the case of This situation. For medium and high frequency devices, if the designed frequency converter (inverter device such as a solid) to provide reliable short-circuit protection, may be omitted if the It said measures to enhance short-circuit protection. Interior design should be taken to avoid excessive overcurrent.

9.4 cables and wires in the heating zone generally has a high mechanical strength and insulating layer of the heat-resistant strength. In most cases, this insulation Layer of shock protection is not enough. Therefore, if the operating voltage exceeds the allowable contact voltage (see 13.1.1), measures should be taken, To prevent accidental contact with the wires and cables in operation.

By GB 6.6 and the following additional 5959.1-2005. supplement.

10 Liquid cooling

10.1 pairs of high-frequency operation apparatus in the third voltage segment, in which the cooling system to avoid the formation of bubbles, as bubbles may be generated in Arcing damage the cooling system.

10.2 with fabric reinforced hose, it is possible moisture penetration into the reinforcement fabric along, thereby generating a potential between the reinforcement and the cooling liquid Difference, the potential difference may exceed the electrical strength of the hose wall.

Thus, when selecting hose material and a hose arrangement for this in mind.

10.3 Some liquid cooling element (example.

10.4 cooled below the dew point should be avoided, since this condensation may form, such as the formation of condensation in the heating coil and the inductor terminals, from Which may lead to a short circuit.

11 Nameplate

According to GB 5959.1-2005 of Chapter 15 and the following supplements. supplement.

Main components electrothermal device (for example. heat sensors, contact system) should have a respective plate.

12 Clearances and creepage distances

High and mid clearances different means and creepage distance, with frequency (50Hz/60Hz) under used.

When a smaller value (e.g., a high-frequency generator), measures should be taken to prevent arcing and safety hazard.

13 Protection against electric shock

According to GB Chapter 9 and the following additional 5959.1-2005.

13.2.2 insulating material due to temperature changes, the lining and the electrical components (such as capacitors, water-cooled winding), in particular due to the cooling water of Changes in water temperature and quality of the insulation resistance of electric components in the device are changing throughout the operating cycle.

Insulation resistance is generally not given. Therefore, when the delivery device production setting protection device (e.g., a leakage current detecting means for ground)

When the value of the operation, it is necessary to consider these variations.

When the induction heating apparatus having a relatively large leakage current, and electric power supply means need to be electrically isolated.