What type of cables are used under the sea?

What type of cables are used to resist the corrosion of seawater?

Vietnam has a coastline of more than 3,260km stretching across 28 provinces. It brings valuable resources to attract domestic and foreign tourists. Therefore, resorts near the sea are increasingly being expanded. However, projects near the sea often face difficulties in choosing power cables that are resistant to seawater corrosion and ensure a stable signal transmission.

How are beach resorts in Vietnam developing?

With a total coastline of more than 3,260km spanning 28 provinces, the entire coastline of Vietnam is a combination of more than 125 fine sand beaches and 3000 large and small islands. Therefore, modern and luxurious buildings to serve tourists are increasingly being developed by investors. Typically, beautiful beaches are concentrated with many international five-star resorts such as Ha Long, Da Nang, Phu Quoc, Nha Trang, and Khanh Hoa.

What difficulties do projects near the sea often face?

Building a project located on the coast requires a large number of power cables that can withstand the salinity of seawater. In addition, electrical cables must be watertight, especially at the joints, and resistant to corrosion and abrasion caused by ocean currents and waves.

  • Electric cable products used in coastal resort projects need to meet the following basic requirements:
  • Works well in seawater environment, withstands the salinity of seawater, limiting corrosion by sea salt.
  • Make sure the transmission line is always stable in case of underwater installation.

To understand more about the difficulties arising in the construction of cables in the most intuitive way, let's find out about the Sun Signature Show water music stage of Sun group that we, HELUKABEL Vietnam, are honored to join.

In the Sun Signature Show project, our customer encountered a problem in choosing the installation method for the electrical cable system of the water music stage. The electrical cable system is installed completely underwater, so the cables are required to have properties to withstand the corrosion of sea salt for a long time. There are 2 proposed installation options including:

  • Option 1: Install cables directly under seawater to facilitate the electrical system maintenance.
  • Option 2: Installing pipes to prevent seawater from direct contact with electrical cables. However, with this method, the maintenance process will face many difficulties.

Finally, we, HELUKABEL, have solved the investor's worries and brought an underground electric cable solution that meets the standards of direct installation in the seawater environment with the ability to withstand seawater salinity up to 3.5 % while the actual salinity of seawater is 3.2%. The product of choice is the HELUPOWER® AQUATIC cable.

In addition, in this project, we also accompany and support customers in delivery time. With the urgent construction schedule and the need to complete the project on time, we have transported all electrical cables from Germany to Vietnam by air, helping customers solve the problem. Now, the Sun Signature Show project has contributed to creating an impressive work, adorning Phu Quoc island, contributing to promoting the image of Vietnam's tourism.

HELUKABEL Vietnam has provided HELUPOWER® AQUATIC-750-BLUE cables for the Sun Signature Show project.
HELUKABEL Vietnam has provided HELUPOWER® AQUATIC-750-BLUE cables for the Sun Signature Show project.
HELUKABEL Vietnam has delivered power cables to the Sun Signature Show project.
HELUKABEL Vietnam has delivered power cables to the Sun Signature Show project.
HELUKABEL Vietnam has delivered power cables to the Sun Signature Show project.
HELUKABEL Vietnam has delivered power cables to the Sun Signature Show project.

Some control cables is applied for projects near sea


Special cable in reference to DIN VDE 0250 / DIN VDE 0285-525-1 /DIN EN 50525-1

Temperature range:

  • flexing: -25°C to +50°C
  • fixed installation: -40°C to +80°C

Temperature in water: +60°C

Permissible operating temperature at conductor: +90°C

Nominal voltage: U0/U 450/750 V

Test voltage: 2,5 kV

Minimum bending radius: fixed installation 5x outer Ø



Rubber connection cable acc. to DIN VDE 0285-525-2-21 / DIN EN 50525-2-21

Temperature range

  • flexible -40°C to +90°C
  • fixed -50°C to +90°C

Permissible operating temperature of the conductor: +90°C

Short-circuit temperature at conductor: +250°C

Nominal voltage: AC Uo /U 450/750 V

Max. permissible operating voltage:

  • Alternating current (AC) conductor/earth 476 V
  • Three-phase alternating current (AC) conductor/conductor 825 V
  • Direct current (DC) conductor/ earth 619 V
  • Direct current (DC) conductor/ conductor 1238 V

Test voltage core/core: 2500 V

Minimum bending radius:

  • flexible 6x Outer-Ø
  • fixed 4x Outer-Ø

Installing underground electric cables requires the process of researching and finding out the problems and risks that may arise during the construction process. From there, we can offer a solution to handle and choose the most suitable cable type. In addition, besides the two electric cables immersed in seawater, you can also refer to other products that can be installed near the sea, such as F-CY-JZ or outdoor power cord H07RN-F.

We, HELUKABEL Vietnam, are always ready to accompany you in choosing the optimal solution for the project. With a portfolio of more than 33,000 products and experienced engineers, we can deliver products that meet specifications and provide complete solutions for a wide variety of projects. If you need solutions for electrical connection technology, please contact our engineers for advice.

For more information, please contact:


905 Nguyen Kiem Street, Ward 3, Go Vap District, Ho Chi Minh City 700000, Vietnam

Tel. +84 28 77755578 | info@helukabel.com.vn | www.helukabel.com.vn


See more control cables for your projects at our E-store on Tiki HERE.