Medium voltage cable 33kv

Introduction

33KV medium voltage cables are fundamental in modern electrical distribution, especially in industrial applications, urban infrastructure and renewable energy projects. These cables are designed to operate nominal tensions up to 33KV and must comply with international regulations such as IEC 60502-2 and the Bs 6622.

What is a medium voltage cable 33kv?

And medium voltage cable 33kV It is an electric conductor designed to transport electricity in the range of 1kv to 35kv, being the 33KV one of the most common tensions in industrial applications, Urban electric distribution networks and infrastructure projects.

This type of cable is usually used for the connection between substations, feeding large industrial facilities and connection of wind farms or solar with the electricity grid. Its construction must meet strict security requirements, Mechanical insulation and resistance.

General structure of the 33KV cable

A typical 33KV cable consists of the following layers:

Conductor: It covers the aluminum, generally wiring for greater flexibility.
Internal semiconductor screen: Minimizes electrical stress in insulation.
Isolation: XLPE (cross-linked polyethylene), resistant up to 90 ° C in continuous operation.
External semiconductor screen: Ensures a uniform distribution of the electric field.
Metal screen: Copper threads or tapes for potential control and short -circuit protection.
inner cover: Provides a separation layer between the metal screen and the armor.
Armor: Steel threads (SWA) For tripolar or aluminum cables (AWA) For unipolar cables.
External cover: PVC, OR of LSZH, according to environmental conditions and security requirements.

33KV cable types: Copper vs. Aluminum, Unipolar vs. Tripolar

Los medium voltage cable 33kv are available with drivers of copper o aluminum, as well as in versions unipolares (A single driver) o tripolares (Three integrated conductors).

Copper: Best conductivity, more compact, greater weight and cost.
Aluminum: cheaper and light, but with greater diameter for the same capacity.

Advantages of 33KV cable with XLPE or EPR insulation

Medium voltage cables at 33KV are usually isolated with XLPE (cross-linked polyethylene) o EPR (Ethylene rubber propylene):

XLPE: Excellent thermal resistance (90–130°C), lower weight, Simple installation.
EPR: High flexibility, Ideal for areas with pronounced curves.

Both types are suitable for air facilities, directly buried or in ducts.

Technical specifications of copper cables

Copper properties

High electrical conductivity (~57 MS/m).
Excellent mechanical resistance.
Greater weight and cost compared to aluminum.

Technical data for copper unipolar cables (33kV)

Next, Specifications for medium voltage cable 33KV copper unipolar with XLPE insulation are presented:

Section (mm²)	Approximate outer diameter (mm)	Approximate weight (kg/km)	Nominal current in air (A)	Nominal current on land (A)
25	29	1000	140	120
35	30	1100	170	145
50	31	1250	200	170
70	33	1500	250	210
95	34	1800	300	250
120	35	2150	350	290
150	37	2400	400	330
185	38	2800	460	380
240	42	3400	540	440
300	43	4000	620	500
400	44	4950	720	580
500	46	6050	820	660
630	50	8150	950	760
800	53	9600	1100	880