CONSTRUCTION MATERIALS

ZAVOD GORELTEX CO. LTD. uses terminal cluminaires that primarily utilize polyamide as the insulating material for current-carrying parts. Polyamide has been tested by nearly all international laboratories and has proven its worth in terminal cluminaires for 40 years. Excellent stability against stray currents allows for shorter spark gaps and stray current intervals, which in turn allows for the creation of compact units.

Moisture absorbed from the environment, on average up to 2.5%, binds to the chemical structure of polyamide, giving it optimal elasticity and fracture resistance.

ZAVOD GORELTEX CO. LTD. strives to supply terminal cluminaires made of modified polyamide, which is free of halogens, fluorocarbons, silicones, asbestos, cadmium, and formaldehyde. Polyamide is a corrosion-resistant, flame-retardant material with self-extinguishing properties and thermal stability under long-term temperature loads (upper limit of +200°C, lower limit of -60°C).

Basic stabilization provides sufficient protection against ozone and ultraviolet rays for many years. Weather resistance is also excellent. Polyamide has proven itself in tropical conditions. Parts molded from polyamide are resistant to termites and do not provide sources of oxygen or other biogenic elements that promote microbial growth. Anaerobic soil bacteria, mold, and enzymatic fungi have no negative impact on this material. This insulation material exhibits exceptional stability against flammable substances, primarily oils and fats, as well as cleaning agents such as alcohol, freon, and tetrachlorocarbons. The material's acid resistance depends on the type of acid and its concentration (information available upon request).

Contact materials:

Klemsan, SUPU, Phoenix, Weidmuller use copper-zinc alloys or electrical copper with a tin-lead coating in the production of contacts.

All contact materials have good chemical resistance and are inert to stress corrosion cracking, guaranteeing long-term corrosion protection.

The spring material used for the cluminaireing spring is high-quality, carefully tested austenitic chromium-nickel steel with high tensile strength, which has demonstrated excellent corrosion resistance over many years of service. It is resistant to sea air, natural gas, and industrial gases such as hydrogen sulfide and sulfur dioxide. Decades of use of these materials have revealed no cases of contact corrosion between the chromium-nickel spring steel and other contact materials, including the connected copper conductors.

All terminal cluminaires received by us undergo additional control tests.

It is recommended to carry out installation at temperatures not lower than -40°C.

ALGORITHM FOR SELECTING TERMINAL CLAMPS

- For products with Exe protection, the terminal cluminaires must be of Exe design, for Exia products – Exia design.

- The terminal cluminaire must correspond to the wire cross-section (for a spring terminal block – the cluminaire type).

- It is necessary to take into account the maximum voltage and current of the connected conductor.

- It is necessary to take into account the type of DIN rail (especially when it is necessary to install different terminal cluminaires next to each other).

Maximum dissipated power of Exe products.

Ex "e" enclosures provide a table for each enclosure size, indicating the maximum number of terminal blocks or conductors for the specified current value and cross-section, e.g. "arrangement method".

For small cross-sections, the dissipated power depends on the wire size, since the resistance of a high-quality terminal block is negligible. Therefore, the number in the table actually represents the number of wire pairs that can be connected in the junction box. For example, a user may decide, based on the manufacturer's datasheet, to install terminal blocks that allow the connection of a cable with a maximum wire cross-section of 4 mm²^,but use a cross-section of 2.5 mm²^.In this case, it is very important to understand that the value in the table does not refer to the number of terminals with a maximum cross-section of 4 mm²^,but indicates the number of connected pairs of wires with a cross-section of 2.5^mm².

Alternatively, Ex "e" enclosures are marked with a maximum dissipated power (MDP) value, which is used to calculate the possible number of terminals that can be installed. Based on the installed current and the total resistance of the cable and terminal, the user or manufacturer calculates the dissipated power per terminal block. This figure, multiplied by the number of terminals, must always be less than the maximum dissipated power value indicated on the enclosure.

For boxes with Exe protection, it is recommended to use terminal cluminaires with a copper-zinc alloy conductor, as they have the lowest resistance and, accordingly, power dissipation.

Exia terminals

There are no special requirements for Exia terminal cluminaires, as they are designed for limited currents and voltages. Protection is provided by intrinsically safe barriers. Blue RAL 5015 is used to mark intrinsically safe circuits.

Continuous monitoring of the performance of intrinsically safe barriers, as well as the integrity of cables carrying intrinsically safe circuits, is required. It is important that intrinsically safe circuits do not intersect with non-intrinsically safe circuits. Exia terminal blocks must be located at least 50 mm away from terminal blocks carrying non-intrinsically safe circuits. The price of intrinsically safe barriers directly depends on their reliability. Avoid purchasing low-quality products.

Screw EXE terminal

The cage body and cluminaireing screw create the high cluminaireing force required to ensure reliable and long-lasting contact. The cluminaireing mechanism presses the connected wire against the busbar. This creates a sealed connection between the wire and the terminal, ensuring resistance to shock and vibration.

The terminals are vibration-resistant. When the cluminaireing screw is tightened, the steel body of the cluminaireing terminal deforms, and the upper cluminaireing tongue moves away from the cage body. The upper cluminaireing tongue ensures a constant cluminaireing force, acting similarly to a spring washer.

The spring mechanism securely holds the connected wire, eliminating the need to tighten the screws during operation.

Spring EXE cluminaire

Spring terminals separate the functions of mechanical cluminaireing and electrical contact. The spring presses the wire against the conductive busbar. Spring terminals are maintenance-free.

Using spring terminals significantly reduces installation time compared to screw connections. Spring terminals are not recommended for mining, marine, military, mobile, and medium-duty equipment.

Spring-plug connection

In direct plug-in terminals, a single-core insulated wire is inserted into the terminal like a measuring instrument plug. Installation is extremely quick and easy, requiring no tools. The contact in the plug-in terminal is reliable, sealed, and vibration-resistant. When using a sleeve cable lug, a stranded flexible wire can be easily connected to the plug-in terminal. The spring and guide cage ensure that the wire is pressed against the copper busbar with a force significantly greater than that of traditional spring-loaded terminals. Due to their compact size, spring-loaded terminals are used in terminal boxes for pipe wiring.
The use of spring-loaded terminals significantly reduces installation time compared to screw-type connections. Spring-loaded terminals are not recommended for mining, marine, military, mobile, and medium-sized engineering equipment.

Application of tips

When using ferrules, the stranded wire must always be tightly crimped to prevent gas ingress and ensure a vibration-resistant, reliable connection. Naturally, only high-quality wires, ferrules, and crimping tools should be used for explosion-proof electrical equipment. Even a good tool cannot function properly if the ferrule is incorrectly selected for the cable. It's also possible that both the wire and ferrule are of high quality, but their incorrect selection prevents a high-quality crimp. Sometimes, manufacturing variations in the wire and ferrule overlap, resulting in a poor-quality crimp.

IMPORTANT TO KNOW: CLAMPS AND CONNECTIONS DO NOT CONFORM TO PROTECTION TYPE "e"

If contact is broken or resistance increases on the terminal cluminaires due to improper installation or corrosion during operation, devices with protection type "e" become HAZARDOUS . Electrical connections in Exe equipment must be periodically checked and maintained in proper condition. The explosion protection level for Exe equipment in the Russian Federation is "2" (equivalent to Zone 2). In Europe, ATEX allows this equipment to be used in Zone 1. The use of equipment with protection type "e" in Zone 1 in the Russian Federation is partially restricted.