Arc-flash calculations improve safety
Everyone deserves to go home without injury at the end of the (working) day.
During the course of any kind of work on a power grid there is a risk of short circuits and arc flash hazards occurring. Arc flashes are rare, but the consequences are disastrous. Mechanics, installers and bystanders are at great risk from the massive explosion triggered by an arc. Optimal arc flash protection is an absolute necessity. Predicting the behaviour of the arc flash will increase safety. It will provide insight into risks and how to manange these risks best. Knowing the electrical energy in every distribution board determines the right PPE for all situations.
HyTEPS provides arc flash calculations and simulations
The most recent NEN 3140 standard has an increased focus on the danger caused by electric arcs. In order to reduce risk and take appropriate protective measures, an RI&E in the field of electric arcs is required. Based on installation data, the arc energy at a specific workplace (for a specific device or part of the installation) needs to be determined. This makes it possible to specify whether arc protection is required, and what this protection would need to consist of. However, determining arc energy is complicated. A variety of factors need to be taken into account, including the duration of the fault, the level of the current and the distance between individuals and the installation.
HyTEPS provides arc flash calculations and simulations
For every cabinet, HyTEPS can provide you with labels, listing the most important safety data such as short circuit power, and information on which PPMs should be worn for different situations, based on simulations. This simplifies LMRA (Last Minute Risk Assessment) making it efficient to carry this out for each individual cabinet. If desired, this can be linked to a management system, which provides central data allowing you to know which PPMs are necessary at your plant. This increases awareness and supports a safer work culture.
What is an arc flash?
An arc flash is a sustained electrical arc that can result from switching or a failure within an installation. Often, an arc flash will have a negative incremental resistance. This means the arc will grow until a component elsewhere in the installation fails due to overcurrent. Only then will the arc die out.
Characteristics of an arc fault
- Extreme temperatures in excess of 19,000 degrees Celsius
- Flying (heated or melted) fragments of the installation
- A pressure wave with a deafening bang (arc blast)
- An intense bright light, in both the visible and invisible spectrum (infrared)
Risks for your employees
- External burns
- Internal burns due to inhaled ionized gases
- Blindness (temporary or permanent)
- Hearing damage (temporary or permanent)
- Copper poisoning (the inhaled copper fumes will solidify in the lungs, resulting in the permanent presence of copper residue in the lungs.)
In extreme cases the arc fault can mean direct, or indirect (due to the reasons mentioned above) employee loss.
The three most important parameters governing the extent of an arc fault are arcing time, fault current and the distance between operator and installation.
Causes of an arc flash
Most arc flashes are produced by human error. In about 70% of all cases, the cause is careless operation of the installation. Furthermore, faults in the installation can also result in a dangerous arc flash:
- Incorrectly sized switching gear
- Decayed or lacking insulation material
- Bad joints
- Conduction between phases due to objects such as tools, parts or rodents
Standard for arc flash calculations
Many standards have been developed to calculate arc-flashes. Every standard has its own application domain and method. Some of the most common rules and regulations are summarized in the table below.
|IEEE-1584 2018||International standard for calculating arc flashes. This version is extended with additional circumstances.|
|IEEE-1584 2002||International standard for calculating arc flashes. Main method for calculating arc flashes.|
|NFPA 70E||National fire protection agency guides concerning arc faults.|
|NEN 3140||Dutch standard concerning operation of electrical installations|
|EN 50110||European standard for safe operations on and around electrical installations|
But also regulations on protective clothing:
|ISSA||Guidelines about thermal effect of arc flash on PPE|
|DGVU203-077||Guidelines about thermal effect of arc flash on PPE|
|IEC 61482-1-1||Test method for PPE against thermal effects and electrical energy|
|IEC 61482-1-2||Test method for PPE against thermal effects and electrical energy|
It is vital to select the right guidelines and regulations for your installation. HyTEPS can advise you in making these decisions.
Dangerous arc flashes: an expensive case
As described, the effects of unwanted arc flashes can be severe. An arc flash can harm people, but also cause major damage to installations such as distribution boards. Due to damage from the arc flash, an installation could be out of service for several days or weeks. Replacing entire cabinets such as feeder systems might be necessary. This leads to direct financial damage - the cost of replacement parts - but also indirect damage resulting from decreasing production capacity. This could also negatively affect market position and business results.
By means of simulations and arc flash calculations, HyTEPS supports you in protecting your employees, and reducing unnecessary risks and unwanted downtime and costs.
HyTEPS is expert in simulating arc faults
We would like to inform you about the possibilities in the area of simulating and reporting arc faults. We strive to deliver tailored solutions, reports and advice, which can be directly applied in order to increase safety and continuity. This improves your knowledge of your own installation, correct operation and security, and answers the question whether the installation has been properly designed for normal as well as emergency operation!