RTTZ(YTTW) Flexible Mineral Insulated Cable Product Introduction

The RTTZ(YTTW) cable is renamed from the original YTTW cable and a national standard has been established: GB/T34926-2017 "Cable with Mica Insulation and Copper Braid Sheath for Rated Voltage 0.6/1kV and Below." The conductor of the RTTZ cable is made of multi-strand copper braiding, the insulation is a high-temperature-resistant synthetic mica tape, and the outer insulation layer is filled with alkali-free glass fiber. The sheath is formed by wrapping and welding copper strips into a copper tube, followed by continuous rolling to create a corrugated shape. For applications where the metallic sheath cannot be exposed, a polyolefin (low-smoke, halogen-free) sheath can be added externally.

Product Name & Applicable Voltage

RTTZ(YTTW) Cable Products
Rated Voltage:

Model and Specification Range

Model Descriptions and Product Examples

1. Product Representation Examples

For example:

Copper-core mica tape mineral insulated corrugated copper sheath cable, rated voltage 450/750V, with specifications 7*1.5mm², represented as RTTZ-450/750V 7*1.5.

Copper-core mica tape mineral insulated corrugated copper sheath polyvinyl chloride outer sheath cable, rated voltage 0.6/1kV, size 4*95mm², indicated as RTTVZ-0.6/1kV 4*95.

Product Name & Applicable Voltage

1. RTTZ Cable's Performance and Advantages

Superior fire-resistant properties:

The fire resistance rating not only meets the national standard GB12666 but also withstands water spray and mechanical impact.

Continuous Length:

Whether single-core or multi-core, the cable length meets the power supply length requirements, with each continuous length exceeding 1000 meters.

Cross-section large:

Single-core cables can have a cross-sectional area of up to 630mm², while multi-core cables can reach 70mm².

Flexible:

Cables can be wound on drums with a bending radius of 6-10D.

Smoke and odorless when burning:

Insulation is made of inorganic materials, which do not emit any harmful gases upon combustion and do not cause secondary pollution, making it an environmentally friendly and green product.

High overload capacity:

Cables not only have a high current-carrying capacity but also offer significant overload capability. According to wiring specifications, the cable surface temperature is typically 70°C. If the wiring is not touchable and does not come into contact with combustible building materials, the cable sheath temperature can be raised to 105°C. During overload, the long-term working temperature of fire-resistant cables can reach 250°C.

Corrosion-resistant:

Excellent shielding performance, copper sheath with good corrosion resistance; in environments corrosive to copper, a layer of low-smoke halogen-free or plastic outer sheath should be added to the copper sheath. Under the shielding of the copper sheath, there is no electromagnetic interference, which will not disturb the transmission of information through signal, control cables, or wires.

Fire-resistant cables can supply power normally in flames (power normally supplied for over 3 hours at 950℃), activate fire extinguishing devices, and reduce fire damage. The copper sheath is an excellent conductor, making it a good grounding wire, significantly enhancing the sensitivity and reliability of grounding protection.

Long service life:

Withstanding high temperatures and resistance to aging, it boasts a lifespan of over 100 years under normal operating conditions.

Simple transportation and installation:

Flexible fire-resistant cable is easy to transport, install, and has simple installation accessories, similar to standard cables.

Economic efficiency:

Flexible fire-resistant cables, due to their advanced manufacturing process and easy installation, are more cost-effective than mineral insulated cables under the same conditions.

2. RTTZ Cable Laying and Installation Precautions

1) RTTZ cables can be laid without personnel, and no installation training is required. If necessary, the manufacturer will send technical staff to assist with installation. For terminal heads and intermediate connectors, please follow the video tutorial:

2) The cable drum can be directly transported to the site for laying, and the laying operation should be performed according to the laying direction marked on the cable drum.

3) Cable Laying Supports and Fixings

a. Horizontal hangers allow span: Cable OD 20mm, span up to 400mm; Cable OD >20mm, span up to 800mm; b. Vertical brackets allow span: Cable OD 20mm, span up to 1500mm; Cable OD >20mm, span up to 1000mm; c. For cable trays, the allowable span for fixed cables can refer to the above; d. It is strictly forbidden to use magnetic materials, such as wire, for fixing single-core cables; e. Single-core cables must not pass through magnetic material pipes or any closed magnetic components individually; in such cases, consider using plastic or resin pipes and components, such as glass fiber trays.

4) Cable accessories, such as intermediate connectors installed on-site, have fire resistance equivalent to the main body. When making field terminations, strip the conductor insulation at the end for about 300mm, crimp the cable lug, and use an ohmmeter to test the insulation resistance between the copper sheath, conductors, and between conductors. After passing, cover it with a heat-shrink tube or wrap it securely with insulating tape to protect the fire-resistant insulation layer.

5) When laying cables on-site and encountering turns, they should be bent in a circular arc; twisting and 90-degree bends are strictly prohibited.

6) Ensure the cable is drawn smoothly; strictly prohibit pulling the cable hard if it gets snagged, to avoid damaging the copper sheath.

4. RTTZ Cable Terminal Heads and Intermediate Connectors

Cautionary Notes:

The RTTZ cable series utilizes a prefabricated branch tree trunk distribution method, with both single-core and multi-core cables capable of being made into prefabricated branch cables. Typically, cable manufacturers measure on-site to determine the connection points, as well as the lengths of the trunk and branch cables, which are then directly formed at the factory. Field installation and laying are convenient and simple.