GB/T 7251.4-2017Low-voltage switchgear and controlgear assemblies -- Part 4: Particular requirements for assemblies for construction sites (ACS) (English PDF)

1.2.3 of GB/T 7251.1-2013, Table 4 of GB/T 7251.1-2013, or Appendix A of GB/T 7251.1-2013.

Articles with numbers 101, 102, 103, etc. are additional terms of the same clause in GB/T 7251.1-2013.

The new tables and diagrams in this section are counted starting from 101.

The new appendices in this section are named after the letters AA, BB, etc.

This part uses the translation method equivalent to IEC 61439-4.2012 "Low-voltage switchgear and control equipment Part 4. For construction

Special Requirements for Site Equipment (ACS).

The documents of our country that have a consistent correspondence with the international documents referenced in this part are as follows.

--- GB/T 19212.24-2005 Safety of power transformers, power supply units and similar products - Part 24. Construction site

Special requirements for transformers (IEC 61558-2-23.2000, MOD)

This part was proposed by China Electrical Equipment Industry Association.

This part is under the jurisdiction of the National Low Voltage Switchgear and Control Equipment Standardization Technical Committee (SAC/TC266).

This section drafted by. Tianjin Electric Science Research Institute Co., Ltd., National Electric Control and Distribution Equipment Quality Supervision and Inspection Center (Tianjin Tianchuan

Electronic Control Equipment Testing Co., Ltd.), Chengdu Product Quality Supervision and Inspection Institute, Tianjin Tianchuan Electric Control Distribution Co., Ltd., Hangzhou Jiuchuan Electric Co., Ltd.

Company, Tianjin Jiu'an Group Co., Ltd., Hunan Electric Apparatus Research Institute, Borui Electric Co., Ltd., Cixi Qiguo Electric Co., Ltd., Ningxia

Licheng Electric Group Co., Ltd.

3.1 General terms

3.1.101

Low-voltage switchgear and control equipment (ACS) for construction sites low-voltageswitchgearandcontrolgearassembly

Forconstructionsites(ACS)

A combination of devices designed and built for use in all construction sites indoors and outdoors. The device consists of one or several transformers or switches

The components are combined with control, measurement, signal, protection and regulation and all electrical, mechanical connections and structural parts inside.

3.2 Structural unit of the complete set of equipment

3.2.101

Metering unit

A functional unit equipped with a power measuring device.

3.2.102

Transformer unit transformerunit

A functional unit consisting mainly of one or several transformers.

modify.

3.3 External design of the complete set of equipment

3.3.1

Open type equipment open-typeASSEMBLY

The terminology of GB/T 7251.1-2013 does not apply.

3.3.2

Fixed panel type equipment dead-frontASSEMBLY

The terminology of GB/T 7251.1-2013 does not apply.

instead.

3.3.3

Closed ACS enclosedACS

In addition to the mounting surface that provides a specific level of protection, the ACS is closed on all sides.

3.3.7

Box ACS box-typeACS

The closed ACS is used to.

---Installed on a vertical surface;

---either supported by a tripod or bracket (hinge or non-hinge) or by means of a fixture that is not an integral part of the ACS

Placed on a horizontal plane (see 3.4.2 of GB/T 7251.1-2013).

modify.

3.5 Installation conditions of complete sets of equipment

3.5.1

ASSEMBLYforindoorinstalation

The terminology of this clause of GB/T 7251.1-2013 does not apply (see 3.1.101).

3.5.2

Outdoor installation equipment ASSEMBLYforoutdoorinstalation

The terminology of this clause of GB/T 7251.1-2013 does not apply (see 3.1.101).

3.5.3

Stationary equipment stationaryASSEMBLY

The terminology of GB/T 7251.1-2013 does not apply.

3.5.4

Mobile equipment movableASSEMBLY

The terminology of GB/T 7251.1-2013 does not apply.

Increase the terminology.

3.5.101

Transportable ACS transportableACS

Semi-fixed ACS semi-fixedACS

For non-permanently fixed locations, ACS whose location may change during work in the same site. When you want to move the device to another

When you are in a position, first disconnect the power.

3.5.102

Mobile ACS movableACS

The ACS that moves on the job site as the work advances without disconnecting the power supply.

Increase the terminology.

3.101 ACS features

3.101.1

Incoming power supply function incomingsupplyfunction

Suitable for connection of ACS to power supply networks or substations or site generators.

3.101.2

Metering function meteringfunction

Suitable for measurement of electrical energy consumption on the construction site.

3.101.3

Distribution function distributionfunction

It is suitable for providing power distribution and power protection for construction sites through terminal connections or sockets.

3.101.4

Transformer function transformerer function

It is suitable for providing a method of changing the voltage or providing electrical protection measures.

Note. Detailed requirements are given in 101.1.

5.3.1 Rated current of the complete set of equipment (InA)

Instead of the title and content.

5.3.1 ACS rated current (InA)

The rated current of the ACS is the rated current of its incoming circuit.

The temperature rise of each part of the ACS when carrying this current shall not exceed the limit specified in 9.2 of GB/T 7251.1-2013.

5.4 Rated dispersion coefficient (RDF)

increase.

The calculated load or outgoing circuit group of the ACS outgoing circuit shall be declared by the complete equipment manufacturer or the value in Table 101.

basis.

The values in Table 101 apply when the manufacturer does not declare any RDF.

5.6 Other features

instead.

The following characteristics should be declared.

a) the function specified by the manufacturer (see 3.101);

b) shape design (see 3.3);

c) mobility (see 3.5.101 and 3.5.102);

d) degree of protection (see 8.2);

e) installation methods, such as fixed or movable parts (see 8.5.1 and 8.5.2);

f) protection against electric shock (see 8.4);

g) corrosion protection (see 10.2.2.101);

h) special conditions of use, if applicable (see 7.2);

i) Electromagnetic compatibility (EMC) rating (see Appendix J of GB/T 7251.1-2013).

6.1 Complete equipment designation identification

Instead of the title and content.

6.1 ACS Designated Logo

The complete equipment manufacturer shall provide one or several nameplates for each ACS. The nameplate shall be durable and its position shall be installed and cast in the ACS.

A place that is easy to see when running.

According to the test of 10.2.7 and by visual inspection.

The ACS should provide the following information on the nameplate.

a) the manufacturer's name or trademark (see 3.10.2);

b) the model number or marking number, or any other marking, from which the relevant information can be obtained from the manufacturer of the equipment;

c) the manner in which the date of manufacture is identified;

d) GB/T 7251.4;

e) current type (and frequency in the case of AC);

f) rated voltage (Un) (ACS) (see 5.2.1);

g) rated current of the ACS (InA) (see 5.3.1);

h) degree of protection (see 8.2);

i) Quality, if more than 30kg.

If the manufacturer's name or trademark is easily identifiable on the ACS, it does not need to be given on the nameplate.

6.2.1 Complete equipment related information

Instead of the title and content.

6.2.1 ACS related information

The following additional information, if applicable, should be provided with the ACS documentation in the kit manufacturer's technical documentation.

a) rated operating voltage (Ue) (of a circuit) (see 5.2.2);

b) rated impulse withstand voltage (Uimp) (see 5.2.4);

c) rated insulation voltage (Ui) (see 5.2.3);

d) rated current (Inc) of each circuit (see 5.3.2);

e) rated peak withstand current (Ipk) (see 5.3.4);

f) rated short-time withstand current (Icw) and duration (see 5.3.4);

g) rated short-circuit current (Icc) (see 5.3.5);

h) rated frequency (fn) (see 5.5);

i) rated dispersion factor (RDF) (see 5.4);

j) function (see 3.101);

k) all necessary information relating to other classifications and characteristics of the declaration (see 5.6);

l) short-circuit withstand strength and characteristics of short-circuit protection appliances (see 9.3.2);

m) Dimensions (including protruding parts such as handles, covers, doors).

6.2.2 Instructions for handling, installation, operation and maintenance

increase.

The ACS manufacturer shall specify in its technical documentation other types of equipment supplied with the ACS, which may be

It is connected. This information should indicate whether compatibility is based on the type of system ground used and/or based on electrical protection coordination in a complete installation.

Need.

In order to maintain the coordination of protective measures and protective equipment in a complete installation, the manufacturer shall assemble the appropriate documentation.

7.1.1 Ambient air temperature

7.1.1 of GB/T 7251.1-2013 does not apply.

Instead of the title and content.

7.1.1 Ambient air temperature for ACS installation

The ambient air temperature does not exceed 40 ° C and its average temperature of 24 h does not exceed 35 ° C.

The lower limit of the ambient air temperature is -25 °C.

7.1.2 Humidity conditions

7.1.2 of GB/T 7251.1-2013 does not apply.

Instead of the title and content.

7.1.2 Humidity conditions for ACS installation

At a maximum temperature of 25 ° C, the relative humidity is as short as 100%.

7.1.3 Pollution level

Instead of the last paragraph.

Only pollution level 3 and pollution level 4 apply.

If the enclosure has a degree of protection of at least IP5X and care is taken to avoid condensation, the microenvironment can be reduced to pollution level 2.

7.2 Special conditions of use

Add the following new column items.

m) Heavy pollution of the environment.

8.1.1 General

increase.

Suppose they are tolerant of the conditions of use of Chapter 7 and the requirements of 8.1.6 and 8.1.2, except for the exceptions mentioned in 8.101, all equipment

It should be placed in an enclosure that is equipped with a removable panel, cover or door for connection or maintenance needs.

8.1.2 Corrosion protection

instead.

Taking into account normal use conditions (see 7.1) and/or special conditions of use (see 7.2), corrosion protection of exposed surfaces should be through the use of suitable materials

Material or ensured by a protective layer. The test of this requirement is carried out in accordance with the test of 10.2.2.

8.1.4 UV radiation resistance

instead.

For exterior parts made of outer casing and insulating material, UV radiation resistance shall be verified in accordance with 10.2.4.

This is not required for external components (such as sockets, switch handles, buttons, etc.) made of insulating materials for other IEC standards.

test.

8.1.5 Mechanical strength

increase.

The structure of the ACS should be able to withstand the mechanical vibration of a half sine wave with an acceleration of 500 m/s2 and a duration of 11 ms (with normal

The equipment for long-distance transportation on the road or railway is quite).

Verification according to the test of 10.2.6.

8.1.6 Lifting device

instead.

The lifting ring and/or handle (or any other equivalent system) shall be provided by the ACS and secured to the outer casing or support frame.

Verification according to the test of 10.2.5.

8.2.1 Protection against mechanical collisions

Increase the paragraph.

The ACS should also withstand a 6 Joule energy collision generated by collisions between the construction machinery handling equipment on the site (see IEC 60068-2-27.

2008).

See 10.2.6 for protection against mechanical impact.

8.2.2 Prevent access to live parts and the entry of external solids and water

instead.

The degree of protection provided by the ACS to prevent access to live parts and the entry of foreign solids and water is specified in the IP code table in GB/T 4208.

Show and verify according to 10.3.

The ACS should have a degree of protection of at least IP44, all doors closed, and all removable panels and covers are fixed.

Ventilation and drain holes should not reduce this level of protection.

Assuming that the door can be closed under all conditions of use, the degree of protection of the working face inside the door should not be lower than IP21. Work when the door cannot be closed

The degree of protection of the face should be at least IP44.

Unless otherwise specified, the degree of protection given by the original manufacturer applies to the entire ACS when it is installed in accordance with the instructions of the original manufacturer.

Sockets that are not protected by the ACS enclosure are at least equivalent to IP44, regardless of whether the plug is pulled out or fully inserted.

When the IP ratings of the ACS are not the same, the original manufacturer shall state the IP rating of each individual part of the ACS in its technical documentation.

For example, IP44, operating surface IP21.

No IP code is required unless properly verified in accordance with 10.3.

8.4.3.1 Installation conditions

Replace the first and second paragraphs.

The ACS shall include protective measures and equipment suitable for design in accordance with GB/T 16895.7.

8.4.4 Full insulation protection

e) The items listed in GB/T 7251.1-2013 do not apply.

8.4.6.2 Relevant requirements for the access of authorized personnel in use

8.4.6.2 of GB/T 7251.1-2013 does not apply.

8.5.3 Selection of switching devices and components

Increase the paragraph.

In order to prevent connection errors, plugs of different rated current or voltage are not interchangeable (see GB/T 11918.1 and GB/T 11918.2).

The three-phase socket should be connected in the same way as the phase sequence.

Add a bar.

8.5.101 Accessible part of ACS

Without the use of a key or tool, only the socket, operating handle and control knob are accessible. Main switch actuator should be easily accessible

(See 704.536.2.2 of GB/T 16895.7-2009).

8.8 Terminals for external conductors

Increase after the third paragraph.

All connections to the external cable should be re-connectable or should be sockets. The socket shall comply with the relevant standards and its rated current shall be at least

16A.

Add a bar.

8.101 ACS support and safety equipment

In order to fix it on a vertical wall connected to the outer casing or support frame, each ACS should be equipped with a support that enables it to stand

On a horizontal plane (such as a tripod or bracket, hinged or non-hinge) and/or on the system.

These supports or safety devices should be external to the housing and securely attached to the housing. They should adapt to structural characteristics (weight, environment

Etc.) and the use characteristics of the ACS and should be tested with the ACS (Chapter 10).

8.102 cable output

The cable output should be the shortest distance from the ground and compatible with the bend radius requirements of the largest cable connected to the ACS.

Verify by inspection.

9.3.2 Information on short-circuit withstand strength

The last two paragraphs of 9.3.2 of GB/T 7251.1-2013 do not apply.

10.2.1 General

Replace the second paragraph.

When using an empty casing conforming to GB/T 20641 and not modifying it to reduce the performance of the casing, it is not necessary to repeat the test in 10.2.

Testing, unless ACS is declared to be suitable for heavily polluted environments [see 7.2m)].

Add a bar.

10.2.2.101 Corrosion proof verification in heavily polluted environments

a) Principle

This test is used for the corrosive effects of industrial environments, such as the environment contaminated with sulfur dioxide.

Completely assembled ACS should be continuously exposed to this environment for ten days.

b) Test method and test environment

The fully assembled ACS shall be tested in accordance with GB/T 2423.19.

c) Test results

Think ACS is satisfactory if

--- No traces of corrosion (except for sharp edges) and no internal or external;

--- ACS is removed from the laboratory between 24h and 36h, according to the test of 10.9.1 of GB/T 7251.1-2013,

There is no obvious damage in the ACS.

10.2.6 Mechanical collision

Instead of the title and content.

10.2.6 Verification of mechanical strength

10.2.6.1 General

a) These tests shall be applied to the ACS, and the test samples shall be arranged in the order of work but not connected to the power source.

These samples should be completely exposed.

b) The test consists of two different procedures.

--- Collision test;

--- Vibration test.

The ACS shall be tested at this temperature after 12 hours of ambient air temperature (20 +/- 5) °C.

10.2.6.2 Collision test

a) Principle

Complete ACS [all components are mounted internally and secured to suitable supports and safety equipment (see 8.101) if these components are constructed

Part of the ACS] should be able to withstand a series of 6 Joule collisions acting on the enclosure instead of its internal components.

b) Test method

In order to limit the movement of the ACS under the influence of the above collision to within 0.1 mm, the equipment to be tested should be strictly fixed to the appropriate support.

On the piece. Each face of the ACS should be subjected to 3 consecutive collisions in the following ways.

1) A steel ball with a diameter of approximately 50 mm, with a mass of (500 +/- 25) g, should allow the steel ball to be from a vertical height of 1.2 m

Free fall from rest to the same level in the surface of the outer casing. The ha...