Controlled Engineering Solutions is highly skilled in arc flash analysis. Our personnel have been trained and gained extensive experience in the identification and assessment of equipment and switchboards that could potentially create an arc flash hazard.
We possess the software and tools to analyse arc flash risks, as this is just one component of power systems design.
As with all CES operations, the safety of personnel is our primary concern.
Defining Arc Flash
An arc flash is a plasma cloud of molten copper, exceeding many thousands of degrees Celcius.
An arc flash is created by the breakdown of insulation of an electrical system, either between a phase to earth or a phase to phase fault, this produces an explosive molten mixture of gases and copper.
The intensity of an arc flash is measured on the quantity of energy that can be delivered to a fault condition and for the length of time that fault condition exists.
Arc Flash incidents pose a significant risk to safety, and there are many interventions to prevent them.
Arc Flash Services for Greenfield & Brownfield Sites
A core service for CES is our power systems engineering for greenfield sites, where arc flash analysis is an inherent component of electrical design.
We also conduct arc flash studies on existing infrastructure on brownfield sites. There are sites with switchboards that have been in operation for multiple decades, they were built at a time when there was little understanding of arc flash, so many do not have appropriate safety mechanisms and pose a risk to current staff.
We assess the physical attributes of the switchboard and electrical parameters. We gather this data and input it into our software package, we then model protection settings to reduce the arc flash incident energy level. We may also look at the installation of remote switching, allowing personnel to operate devices from a remote location.
Arc flash studies are undertaken for any modifications or upgrades. This is mandated by the Australian Standards.
One change in the power system (i.e. changes with power authority network is particularly prevalent, or replacing transformers etc) will alter the potential arc flash energies and void the initial studies. As such, CES is routinely conducting arc flash studies for our clients.
Steps to Conducting an Arc Flash Analysis
Arc flash mainly depends on incident energy level, the duration the fault is present before the protection clears the fault. The injury levels could be extensive.
The overall steps to conducting an analysis are:
- Assess the switch board and related equipment in regard to its potential to house an explosion and forces that are created by an arc flash incident;
- Obtaining relevant data. This is primarily system impedances that would either enable or limit the fault conditions. We then enter this data into our software package, where we model and calculate the amount of energy that is present;
- We design appropriate protection devices. This includes analysing the settings on those protection devices to ascertain the potential duration of an arc flash incident. The quicker that we are able to isolate the arc flash using protective devices, the lower the energy level will be;
- Using the hierarchy of controls, i.e. elimination, we look for the opportunities of ARC Flash containment, Remote operation of switchgear, fast acting protection devices and finally PPE to minimise the effects of ARC Flash;
- We establish safe operating boundaries and recommend safety clothing for site personnel.
Arc Flash Analysis Outcomes
Our core deliverable is establishing safe operating locations for the operators.
The barriers or the parameters could be extensive. This service will yield the following outcomes:
- Switch buttons to automatically control devices from remote locations
- Establish safe operating boundaries
- Labelling on switchboards to warn for arc flash hazards
- Compliance with IEE1584 standards
- Identify safety workwear for each location
Arc Flash is one component of what we do, view our capabilities and immerse yourself a companywide awareness of safety and risk management.
How Arc Flash Risks are Mitigated
In terms of limiting arc flash potential, this can be achieved in various ways.
One way is to design the switchboard using double insulated busbars (copper conductor inside the switchboard that carries current) sections, and thus a higher degree of separation in between the switchboard components, so the potential for arc flash is reduced.
Certain companies make fusing blocks, which significantly lowers the amount of current that will arrive at the fault, so the energy that will be dissipated by the flash is lower.
The duration of arc flash is primarily lowered by fast-acting protective devices.
One example of this is detecting an arc flash using a light device called an arc flash sensing relay. This device looks at the wavelength of the light, and at the inception of an arc flash (changed to pressure & plasma), this device will send a signal to trip the circuit breaker to minimise the arc flash incident energy within 40 milliseconds.
Arc Flash FAQ
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Does CES help with the design of the physical enclosure around the electrical equipment?
No, this is typically handled by a switchboard builder. CES is primarily looking at the electrical design, specification and modelling, ensuring the components are specified and provide the desired safety and compliance requirements.
There are variations on the methods of how the arc flash energy is controlled, whether vented or contained. CES is experienced in collaborating with switchboard companies to achieve the necessary result.
Switchboard designers in some instances will undertake “type testing” of a switchboard design, performing real-world simulations of ARC faults (explosions), proving their design as being able to contain ARC Flash energies to a particular level, ensuring the protection of personnel operating this equipment. There are few companies in Australia that conduct this testing.
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Is CES compliant with IEE1584 standards?
Yes, these are the standards we use.
There is currently no defined Australian standards for this facet of electrical engineering, there is only international NFPA 70E standards. This may change in the future.
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Is CES aware of the changes to AS3000 in 2018?
Yes, the latest edition of AS3000 was released in 2018. There were significant changes to AS3000 in relation to arc flash, simply because there have been a lot of incidences.
Now, there is a requirement for all switchboards to use a design that will minimise the effects of an arc flash.
Additionally, in the appendix, there is information in the appendix that relates to protecting against fire hazards as a result of arc flash.
CES has many years conducting AS3000 audits and is well versed in this area.