3 mins read
Learn how to set priorities and adjust protective devices for selective coordination to isolate faults and minimise outages in electrical systems.
2 mins read
Learn how to set and coordinate circuit breakers to meet AS/NZS 3000:2018, ensuring faults are isolated quickly and safely in electrical systems.
4 mins read
Learn about thermal analysis for HVDC submarine cables, focusing on the 2 K Criterion to minimize environmental impacts.
10 mins read
The calculation of submarine cable current ratings is different from land cables due to their complex construction and installation conditions.
5 mins read
Soil temperature affects high voltage cable and earthing systems. Equations for soil temperature calculations based on air temperature are provided.
4 mins read
Experienced electrical engineers created this reference list of standards for power systems earthing/grounding for substations, renewable energy, etc.
This article provides a timeline of the key milestones from early 19th century insulated wires through to modern innovations in high-voltage cables.
Cable Pro Web is cheaper with more features than JCalc (which is not free). Choose cable sizing software that scales with your business. This article honestly compares prices, features and ease of use.
10 mins read
Size active, neutral, and earth cables using AS/NZS 3008. The guide covers current capacity, voltage drop, and short-circuit calculations with examples.
10 mins read
Understand how software simulations enhance grid impedance tests, improving accuracy and efficiency in earthing system design and performance evaluation.
7 mins read
New methods address IEC 60287 limitations for soil drying calculations. Considers multiple circuits, load factor, and backfill installations for accurate power cable ampacity.
8 mins read
Explore the factors affecting cable ampacity in trays, including thermal and electromagnetic effects. Learn calculation methods and best practices for safe power cable installations.
Based on extensive field experience, this article recommends the best materials for cable trays for use in offshore facilities such as offshore wind, solar, and oil rigs.
All steps of a real-world arc flash calculation example of a low-voltage AC installation with transformer, main switchboard, and distribution boards are explained.
3 mins read
Miniature Circuit Breakers (MCBs) protect against overcurrent in electrical circuits. MCBs are categorised based on their tripping characteristics, represented by different device curves such as Z, B, C, K, and D. This article offers guidance on selecting the right type for your application.
5 mins read
It's difficult to decide on the thermal resistivity of soil or backfill to use for cable rating studies. The typical thermal resistivities of common native soils and engineered materials used as backfills for buried cables are provided in tables.
2 mins read
The AS/NZS 3000 Standard provides different rules in Appendix C for maximum demand with socket-outlets for domestic, commercial, and industrial electrical installations. Calculation examples are provided involving double socket-outlets.
7 mins read
We've reviewed the top 3 electrical engineering design software packages in 2024 that are designed for Australian conditions and electrical standards. We've compared the features, capabilities, pricing, and technical support.
5 mins read
The widely accepted maximum operating temperature of XLPE insulated power cables under “normal use” conditions is 90 ˚C. During emergencies, the temperature of a buried cable may be permitted to exceed this temperature. The duration considered for such emergencies ranges from 10 minutes up to 15 days. In many countries, XLPE-insulated cables are allowed to operate up to 100-105 ˚C for short durations.
9 mins read
We performed ampacity calculations for hundreds of industrial and utility power cables from Southwire. The assumptions used for modelling in the software are explained. The calculated ampacities were all within 3 % of the values given in ICEA and NEC standards.
4 mins read
The standard HV cable rating calculation methods do not cover all real-world situations. This article proposes a new method of finding the current rating for 10 cables touching in the air.
5 mins read
The features of ELEK Cable HV software and CYMCAP software are compared in detail.
10 mins read
This report explains how to perform accurate earth fault current analysis for substations connected by cable transmission lines. Earth fault currents for simple cable and overhead transmission lines are explained first. Next, two case studies involving hybrid cable transmission lines are presented.
6 mins read
The principle of economic cable sizing is to select a minimum cable size that is safe to use and the cost of the losses over the lifetime is also minimised.
17 mins read
Explains the effects of the installation conditions and the bonding arrangement on the current rating of high voltage power cables.
7 mins read
Equations for calculating conduit sizes and space factors in accordance with standards are provided. Worked examples of conduit sizing calculations are provided.
7 mins read
The AC resistance of a cable conductor is always larger than the DC resistance. The primary reasons are ‘skin effect’ and ‘proximity effect’. Equations and example calculations are provided in this article.
5 mins read
Copper is often preferred for its superior electrical properties, while aluminum and galvanized steel are chosen for cost-effectiveness. Copper-clad steel can offer a balance between cost and performance. This article demonstrates which option is best for different scenarios.
8 mins read
Accurate high voltage cable current ratings achieved - ELEK Cable HV software matches CIGRE TB 880 and performs IEC 60287 compliant calculations.
3 mins read
Explains the fundamentals of oil-filled cables current rating calculations to IEC 60287 and provides and example calculation for a 400 kV single core cable.
13 mins read
The technical guide explains the electrical systems, local WTG and combined earthing system design, touch and step voltage hazards, soil electrical resistivity measurements, earth fault currents, earthing system software modelling, and validation testing of earthing for wind farms.
4 mins read
There are two reasons, according to the standards, why crushed rock or gravel is laid in substations, as explained in this article.
11 mins read
Sheath bonding is one of the most important design aspects for high-voltage cable power transmission. Solidly, single-point, and cross-bonded systems are explained.
1 min read
During an earth fault on a substation earth grid, the flow of current to the earth will produce voltage gradients. An earth grid that is properly designed will safely dissipate current into the ground.
The fault current which flows in a power cable causes its temperature to rise dramatically. The adiabatic equations for calculating the minimum conductor size to withstand the short circuit are explained.
4 mins read
Reach touch voltages are different to touch voltages and automatically set to zero when the distance between the voltage point on the ground surface and the grid conductor which is touched exceeds a reach distance.
7 mins read
Crossing multiple cables or heat sources at a crossing angle causes a current rating reduction, calculated using IEC Standard 60287.
4 mins read
New 13 kV power circuits will be installed in an unfilled trough with ventilated covers. These new circuits will cross with existing buried 400 kV cables at approximately 90 degrees with a continuous current rating requirement of 1136 MVA (1640 A) per phase for all seasons.
8 mins read
Most power cables have a design life of between 20 to 30 years. If the cables are not fully loaded, they are expected to last beyond their design life. The insulation is the weakest part of a cable. Montsinger's Rule states: Insulation life is halved by a temperature increase of 8 to 10 ˚C. An example calculation using the Arrhenius equation is provided.
The definition of “touch voltage” is the voltage between accessible exposed and extraneous conductive parts that may lead to the risk of electric shock in the event of an electrical fault. This article covers AS/NZS 3000, BS 7671, and NFPA 70E rules concerning touch voltages and provides the equations for calculations.
This article explains how to calculate the current rating of cables in J-tubes. Typically J-tubes are the thermal bottleneck of submarine power cable routes.
8 mins read
A new calculation method based on FEM and IEC 60287 for current rating of HV cables in soils with multiple different thermal resistivities is explained with an example calculation. Modelling the different soil thermal resistivity zones (multiple backfills) is important for obtaining accurate cable current ratings.
12 mins read
DC cable sizing has significant implications on a PV system's performance, total cost, and safety. Example calculations of Current Rating and Voltage Rise have been provided.
2 mins read
One of the main factors determining the severity of an arc flash injury is the proximity of the worker to the arc flash, also known as the working distance. Working distances from AS (ENA), IEEE, NFPA and DGUV Standards and Guides have been provided.
3 mins read
The effects of lightning strikes on earthing or protection systems designed to IEC 62305 can be modelled using an equivalent single frequency from 25kHz up to 1MHz which gives similar results to a time-domain approach. This article provides the frequency and current values to be used for modelling lightning.
5 mins read
The methods for calculating the current rating of multiple cables installed in ventilated tunnels are explained with example calculations. Overall tunnel length and air velocity inside the tunnel have a significant impact on cable current ratings.
3 mins read
The calculation of current ratings for groups of (multiple) cable circuits require the quantification of the mutual heating component between the groups of circuits. This example is for multiple groups of circuits in air on the same cable ladder. This article will discuss the IEC 60287 approach.
2 mins read
A report investigated 6214 cable failures over a 14 year period. The main causes were insulation breakdown, excavation, joints or switchgear failure. The results may surprise you.
The effects of lightning strikes on earthing or protection systems designed to IEC 62305 can be modelled using an equivalent single frequency from 25kHz up to 1MHz which gives similar results to a time-domain approach. This article provides the frequency and current values to be used for modelling lightning.
This report shows the effects of a direct lightning strike to an air terminal installed on top of a building which is connected to a buried earthing system.