Technical Requirements for Installation of Explosion-Proof Electrical Cables in Explosion-Hazardous Locations

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Basic Requirements for Electrical Lines

1 Electrical line wire insulation should be 2 times the rated voltage, and not less than 500V.

2 Insulated wires must be laid in a steel pipe, the steel pipe should be galvanized welded steel pipe for low-pressure fluid transport, and the threaded part of the steel pipe connection should be coated with lead oil or phosphatizing paste.

In places where condensate may condense, the pipeline should be equipped with sealed joints to exclude condensate. Flexible connecting pipes should be used for connections with electrical equipment.

3 The rated voltage of PE (PEN) line insulation of electrical lines should be the same as the phase line voltage and should be laid in the same sheath or steel pipe.

4 The type and provisions of the junction box, splitter box, live joints, isolation seals, and other connectors in the distribution line shall be following the design requirements and relevant specifications.

5 Flammable and explosive places in the distribution line in the 1 zone are strictly prohibited intermediate joints, in the 2 zone there should be no intermediate joints.

6 The lines introducing explosion-proof oil-filled electrical equipment shall use oil-resistant wires or cables, or else there shall be protective measures to prevent the insulating oil from soaking the insulation layer of the wire core.

710kV and the following overhead lines are strictly prohibited across the explosive gas environment.

The horizontal distance between the overhead line and the explosive atmosphere should not be less than 1.5 times the height of the pole (tower).

In the horizontal distance is less than the provisions of the special circumstances and can not be avoided, must be under the design requirements, to take effective protective measures.

Cable transmission lines in an explosion-hazardous environment should be installed per the following requirements:

1 Cable shall not be directly connected to the other

What must be connected in the corresponding explosion-proof junction box or distribution box should be connected or split.

2 Generally armored cable

Cables without armor can be used when the following conditions are met.

a) Plastic-sheathed cables with a voltage of 1kV or less in Zone 1 locations.

b) Cables for control and lighting in Zone 1 premises.

c) Cables for power, control, and lighting in Zone 2 and Zone 11 locations where the voltage is 1kV or less.

3 Installation after sealing

Explosion-proof electrical equipment, and junction box inlets after the introduction of cable sealing, should meet the following requirements:

a) Compression nut, metal gasket, elastic sealing ring, and sealing filler, should meet the design requirements.

b) When the outer diameter of the cable is equal to or greater than 20 mm when assembling components at the isolation seal to prevent the cable from pulling off, the bolts for fixing the cable shall be tightened after the cable has been tightened or sealed.

Steel pipe wiring in explosion-hazardous locations shall meet the following requirements:

1 Generally galvanized welded steel pipe should be used.

2 The connection between steel pipe and steel pipe, steel pipe and electrical equipment, and steel pipe and accessories shall be threaded.

And shall comply with the following requirements:

a) Thread processing should be complete, and smooth, with no slippery buckles and messy wires, the connection is coated with conductive antitrust grease or phosphatizing paste, and shall not be coated with other oily paints.

b) Thread engagement should be tight, its exposed wire buckle should not be less than 2 ~ 3 buckles.

Pipe engagement effective number of buckles pipe diameter 25 mm and the following steel pipe should not be less than 5 buckles.

A pipe diameter of 32 mm and above should not be less than 6 buckles.

In connection with explosion-proof equipment, threaded connections should be lock nuts.

c) In addition to the design requirements need to make special connections, the connection is generally not welded jumper wires.

d) The electrical piping shall not be connected by an inverted buckle. When the connection is difficult, should use explosion-proof live joints, the joint surface should be closed.

e) Located in an explosive gas environment 1, 2 areas and an explosive dust environment 10 areas of steel pipe wiring, in the following places should be equipped with different types of isolation seals.

&#; Inlet without sealing device.

&#; When the wiring piping passes through an adjacent partition wall, lateral-type isolation seals shall be installed on either side of the partition wall.

The circuit installation of intrinsically safe electrical equipment and its associated electrical equipment shall comply with the following requirements:

The models and specifications of the electrical equipment used for the installation of distribution lines of intrinsically safe and associated circuits, as well as the types and methods of wiring, line direction, elevation, and wiring methods shall comply with the design requirements and the relevant provisions of the product technical documents, and the following requirements shall be met:

(a) Distribution line protection pipe shall be galvanized steel pipe.

(b) Safety circuits and associated circuits shall not share the same cable or steel pipe.

Intrinsically safe circuits are strictly prohibited to share the same cable or steel pipe with other circuits.

Two or more intrinsically safe circuit wiring shall not share the same cable or steel pipe.

© The distance between the terminals of intrinsically safe circuits, associated circuits, and other circuits in the distribution panel shall not be less than 50 mm.

The terminal rows of the distribution circuits shall be insulated with guards. Its circuit wiring should be separately bundled and fixed.

When the distance is less than 50 mm, they shall be isolated by insulated partitions above the terminals or grounded metal partitions.

(d) In addition to special requirements, generally should not be grounded.

(e) The cables, wiring steel tubes, and terminal boards in intrinsically safe circuits shall be marked with sky-blue paint.

Explosion proof cable gland is designed for cable passing and fixation for any explosion proof device, some are flame proof metal body preventing the ignition from transmitting to outer of body, some are increased safety plastic or metal body preventing the ignition arcing from occurring. Before you select the correct explosion proof cable gland, you need to understand those data as below:

1. Suitable Cable Type

explosion proof cable gland type depends on different cable type, there are normally two cable type as below:

> Armored type, extra armored layer inside the cable to prevent damage, armored layer include single wire armor, braided armor, steel tape armor for areas where exposed to potential of mechanical damages, armored cable gland should be used for armored cable.

> Non-armored type, No armored layer inside the cable for basic cable for areas under no risk for mechanical damages, non-armored cable gland should be used for non-armored cable.

2. Wiring Type

Depends on the cable layout method, there is cable wiring and conduit wiring to connect cables as below:

> Conduit wiring to connect the conduit directly and the inside cable indirectly, Cable will be probably put and passed through conduit in order to protected it from mechanical damage, explosion cable gland should have a male threaded end to thread to the conduit, in this case, explosion proof cable gland should be conduit wiring type.

> Cable wiring to connect the cable directly, no extra protection for cable sheath, explosion proof cable gland should be cable wiring type.

3. Sealing Type

Explosion proof cable gland is installed at the cable entry or gland plate of explosion proof equipment, there is single or dual sealing measure to ensure the ingress protection as below:

> Single sealing at the cable entry point

> Dual sealing both at the cable entry entering the hub and at the cable entering the enclosure

4. Cable Gland Material

Explosion proof cable gland normally have two kinds of material, polyamide or metal(nickel plated brass or stainless steel).

> Polyamide body, features in high strain relief and IP68 IP rating to installed in plastic housing for glass reinforced plastic explosion proof light, explosion proof junction box and explosion proof enclosure.

> Metal body, features in corrosive resistance and excellent thermal conductivity performance for metal housing for aluminum alloy and stainless steel material explosion proof lighting, explosion proof junction box and explosion proof panel.

5. Thread Type and Size

Explosion proof cable gland have metric and NPT thread for option:

Metric Thread: M16x1.5-M63x1.5

NPT Thread: NPT3/8 " - NPT2

               Data

Note: P means polyamide, B means nickel plated brass, SS means stainless steel 304/316.

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Basic Requirements for Electrical Lines

1 Electrical line wire insulation should be 2 times the rated voltage, and not less than 500V.

2 Insulated wires must be laid in a steel pipe, the steel pipe should be galvanized welded steel pipe for low-pressure fluid transport, and the threaded part of the steel pipe connection should be coated with lead oil or phosphatizing paste.

In places where condensate may condense, the pipeline should be equipped with sealed joints to exclude condensate. Flexible connecting pipes should be used for connections with electrical equipment.

3 The rated voltage of PE (PEN) line insulation of electrical lines should be the same as the phase line voltage and should be laid in the same sheath or steel pipe.

4 The type and provisions of the junction box, splitter box, live joints, isolation seals, and other connectors in the distribution line shall be following the design requirements and relevant specifications.

5 Flammable and explosive places in the distribution line in the 1 zone are strictly prohibited intermediate joints, in the 2 zone there should be no intermediate joints.

6 The lines introducing explosion-proof oil-filled electrical equipment shall use oil-resistant wires or cables, or else there shall be protective measures to prevent the insulating oil from soaking the insulation layer of the wire core.

710kV and the following overhead lines are strictly prohibited across the explosive gas environment.

The horizontal distance between the overhead line and the explosive atmosphere should not be less than 1.5 times the height of the pole (tower).

In the horizontal distance is less than the provisions of the special circumstances and can not be avoided, must be under the design requirements, to take effective protective measures.

Cable transmission lines in an explosion-hazardous environment should be installed per the following requirements:

1 Cable shall not be directly connected to the other

What must be connected in the corresponding explosion-proof junction box or distribution box should be connected or split.

2 Generally armored cable

Cables without armor can be used when the following conditions are met.

a) Plastic-sheathed cables with a voltage of 1kV or less in Zone 1 locations.

b) Cables for control and lighting in Zone 1 premises.

c) Cables for power, control, and lighting in Zone 2 and Zone 11 locations where the voltage is 1kV or less.

3 Installation after sealing

Explosion-proof electrical equipment, and junction box inlets after the introduction of cable sealing, should meet the following requirements:

a) Compression nut, metal gasket, elastic sealing ring, and sealing filler, should meet the design requirements.

b) When the outer diameter of the cable is equal to or greater than 20 mm when assembling components at the isolation seal to prevent the cable from pulling off, the bolts for fixing the cable shall be tightened after the cable has been tightened or sealed.

Steel pipe wiring in explosion-hazardous locations shall meet the following requirements:

1 Generally galvanized welded steel pipe should be used.

2 The connection between steel pipe and steel pipe, steel pipe and electrical equipment, and steel pipe and accessories shall be threaded.

And shall comply with the following requirements:

a) Thread processing should be complete, and smooth, with no slippery buckles and messy wires, the connection is coated with conductive antitrust grease or phosphatizing paste, and shall not be coated with other oily paints.

b) Thread engagement should be tight, its exposed wire buckle should not be less than 2 ~ 3 buckles.

Pipe engagement effective number of buckles pipe diameter 25 mm and the following steel pipe should not be less than 5 buckles.

A pipe diameter of 32 mm and above should not be less than 6 buckles.

In connection with explosion-proof equipment, threaded connections should be lock nuts.

c) In addition to the design requirements need to make special connections, the connection is generally not welded jumper wires.

d) The electrical piping shall not be connected by an inverted buckle. When the connection is difficult, should use explosion-proof live joints, the joint surface should be closed.

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e) Located in an explosive gas environment 1, 2 areas and an explosive dust environment 10 areas of steel pipe wiring, in the following places should be equipped with different types of isolation seals.

&#; Inlet without sealing device.

&#; When the wiring piping passes through an adjacent partition wall, lateral-type isolation seals shall be installed on either side of the partition wall.

The circuit installation of intrinsically safe electrical equipment and its associated electrical equipment shall comply with the following requirements:

The models and specifications of the electrical equipment used for the installation of distribution lines of intrinsically safe and associated circuits, as well as the types and methods of wiring, line direction, elevation, and wiring methods shall comply with the design requirements and the relevant provisions of the product technical documents, and the following requirements shall be met:

(a) Distribution line protection pipe shall be galvanized steel pipe.

(b) Safety circuits and associated circuits shall not share the same cable or steel pipe.

Intrinsically safe circuits are strictly prohibited to share the same cable or steel pipe with other circuits.

Two or more intrinsically safe circuit wiring shall not share the same cable or steel pipe.

© The distance between the terminals of intrinsically safe circuits, associated circuits, and other circuits in the distribution panel shall not be less than 50 mm.

The terminal rows of the distribution circuits shall be insulated with guards. Its circuit wiring should be separately bundled and fixed.

When the distance is less than 50 mm, they shall be isolated by insulated partitions above the terminals or grounded metal partitions.

(d) In addition to special requirements, generally should not be grounded.

(e) The cables, wiring steel tubes, and terminal boards in intrinsically safe circuits shall be marked with sky-blue paint.

Explosion proof cable gland is designed for cable passing and fixation for any explosion proof device, some are flame proof metal body preventing the ignition from transmitting to outer of body, some are increased safety plastic or metal body preventing the ignition arcing from occurring. Before you select the correct explosion proof cable gland, you need to understand those data as below:

1. Suitable Cable Type

explosion proof cable gland type depends on different cable type, there are normally two cable type as below:

> Armored type, extra armored layer inside the cable to prevent damage, armored layer include single wire armor, braided armor, steel tape armor for areas where exposed to potential of mechanical damages, armored cable gland should be used for armored cable.

> Non-armored type, No armored layer inside the cable for basic cable for areas under no risk for mechanical damages, non-armored cable gland should be used for non-armored cable.

2. Wiring Type

Depends on the cable layout method, there is cable wiring and conduit wiring to connect cables as below:

> Conduit wiring to connect the conduit directly and the inside cable indirectly, Cable will be probably put and passed through conduit in order to protected it from mechanical damage, explosion cable gland should have a male threaded end to thread to the conduit, in this case, explosion proof cable gland should be conduit wiring type.

> Cable wiring to connect the cable directly, no extra protection for cable sheath, explosion proof cable gland should be cable wiring type.

3. Sealing Type

Explosion proof cable gland is installed at the cable entry or gland plate of explosion proof equipment, there is single or dual sealing measure to ensure the ingress protection as below:

> Single sealing at the cable entry point

> Dual sealing both at the cable entry entering the hub and at the cable entering the enclosure

4. Cable Gland Material

Explosion proof cable gland normally have two kinds of material, polyamide or metal(nickel plated brass or stainless steel).

> Polyamide body, features in high strain relief and IP68 IP rating to installed in plastic housing for glass reinforced plastic explosion proof light, explosion proof junction box and explosion proof enclosure.

> Metal body, features in corrosive resistance and excellent thermal conductivity performance for metal housing for aluminum alloy and stainless steel material explosion proof lighting, explosion proof junction box and explosion proof panel.

5. Thread Type and Size

Explosion proof cable gland have metric and NPT thread for option:

Metric Thread: M16x1.5-M63x1.5

NPT Thread: NPT3/8 " - NPT2

               Data

Note: P means polyamide, B means nickel plated brass, SS means stainless steel 304/316.

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