Training & Industry Blogs

Current transformers normally have a single conductor as a primary winding connected in the run of the line conductors. The voltage which appears across the primary terminals is very small and therefore the voltage at…

Before starting to write a switching program, it is important to understand and use standard terminology. The table below includes some common fields found on templates.   Program Field Meaning Program number This is obtained…

High voltage switching is a high-risk task, and as such the use of switching programs is critical. A switching program is a written list of sequential logical operations to permit isolation and re-energisation of electrical…

Ring main units (RMU) are widely used in industry and for distribution systems. RMUs operate independently, which means that it is possible to earth an incoming supply cable while it is still energised from the…

The standard power transformer is “on-load tap changing” (OLTC) to ensure that the secondary distribution voltage is within limits although the primary voltage may change. Tap changer range is usually from 15% above normal to…

Voltage transformers carry full system voltage but no significant current.  They have a fine wire of many turns on the primary winding (very high resistance and inductance) connected between the phase conductor and earth, and…

Earthing switches are usually installed in combination with an isolator and the two should be interlocked electrically or mechanically to ensure that the isolator is open before the earthing switch is closed, and conversely that…

Isolators are simple devices with contacts invariably comprising a moving blade going into two parallel fixed contact faces. The fixed contact faces are usually made up of a number of spring-loaded fingers. The best isolators…

The following basic types are available, typically rated at 350 or 500 MVA at 11 or 22 kV respectively: bulk oil minimum oil air break vacuum SF6 Circuit breakers are designed to deliberately create an…

The main four different switches used in a power system are: Circuit breakers are designed for controlled closing and controlled or automatic opening of load and fault current. Their duties are to close onto a…

The incident energy determined at each assessable location will fall within a defined arc flash/arc blast PPE category, as defined in the table below. Incident Energy PPE Category Cal/cm2 >1.2 to 4 1 >4 to…

Arc flash/arc blast hazard labels inform personnel of the arc flash/arc blast hazard and the required PPE at each switchboard or arc flash/arc blast hazard location. The labels should present the following information: electrical hazard…

The likelihood of an arc flash/arc blast event is dependent upon the type of activity being undertaken at the time. It is generally accepted that the greatest likelihood occurs when there is direct interaction by…

Arc faults are potentially fatal to any personnel in the vicinity. The intense heat of the arc flash/arc blast can severely burn human skin and ignite the clothing of anyone within several feet of the…

The safe approach distance (SAD) is based on an “exclusion zone” principle. This principle defines an area around an exposed conductor into which no part of the person, mobile plant or object (other than approved…

An arc flash/arc blast is a dangerous electrical plasma explosion created by a short circuit through air that causes electric current to flash over from one exposed conductor to another or to ground. An arc…

The main considerations of safe working procedures on electrical equipment are to ensure safety of workers and safety of the general public. In addition to this, the continuity of supply, and the welfare of plant…

Power systems are effectively earthed by the neutral points being connected directly to earth. The only resistance being the inherent resistance of the connections and the earth itself. A system fault comprises either one or…

Most high voltage distribution equipment has four basic ratings – service voltage; basic insulation level; rated current carrying capacity; and fault capacity. Service voltage The IEC sets standards for manufacturers to produce cables and switchgear…

Substations, switchyards and switch rooms are hazardous areas but only become dangerous if procedures are not strictly followed. The safety of personnel is the paramount consideration in the operation of any power system. Substations are…

When an alternating current is made to flow across multiple conductors of a transmission line where its spacing is large compared to their diameters, the air surrounding the conductors (composed of ions) is subjected to…

A question our Technical Specialists get asked regularly on the high voltage courses is: “Do I need to use a switching program every time I operate high voltage equipment“ The short answer is no. The…

Watch the video below to hear High Voltage Specialist Craig Hagan go through the course.    Coex Training’s High Voltage Switching Courses cover everything from basic electrical theory all the way through to physically conducting…

Even when work is not being conducted, caution is needed when entering a hazardous area. Regardless of whether work is to be actioned the following actions should be taken before you enter a hazardous area:…

Permit to work systems are fundamental to ensuring that work is safely actioned. The purpose of the permitting system is to ensure that all work to be performed will not adversely affect plant operations, and…

The plant owner has numerous responsibilities related to hazardous areas. These responsibilities are stated in AS/NZS 60079.2017 book 14 and 17, and include: Ensuring that systems are in place so that all hazardous areas are…

Faulty hazardous area electrical installations have the potential to cause a major catastrophe on a facility. Each state and territory have their own Occupational Health and Safety Act. As of 2019 the legislation is administered…

In this blog, we expand on what the Electrical Equipment in Hazardous Area (EEHA) course covers.  The EEHA course is designed to provide you with the practical skills and knowledge to undertake electrical work in…

A basic knowledge of the nature of fire is needed to assist in the understanding of how explosion-protection techniques make electrical equipment safe for use in hazardous areas. For an explosion or fire to occur…

Many people are unaware of the combustible nature of dust and the issues that it can create. Many organic dusts are combustible such as: wheat flour sugar wood coal some metals & more The best…

Under the Electrical Safety Act (QLD) the requirement is for all “new” Hazardous Area installations to have a Hazardous Area audit completed by an accredited Hazardous Area auditor and the installation found “compliant” prior to…

Hazardous Areas are present on many sites and are often overlooked, from our experience it has been noted that companies treat hazardous areas differently. Some examples; Do not know what hazardous areas are People equate…

Hazardous Areas. Not only are they dangerous, they’re increasingly common. And with Australia outsourcing more projects overseas, regulation has become challenging. So how do we ensure the next generation have the knowledge to work safely…

Do you need skills that are applicable to the real world? It’s one thing to learn new theories, but another to apply them in a practical scenario. At Coex Training, we utilise active training systems…

What can you expect from our Hazardous Area Installation and Maintenance course? Coex Training’s Hazardous Areas courses provide the knowledge and skills to report, inspect, install, maintain and attend breakdowns of electrical equipment in a…

Coex Training is now in partnership with SynergenOG, an independent engineering consulting company headquartered in Kuala Lumpur, Malaysia.   SynergenOG specialises in Process Safety, Technical Risk Management and Operational Safety services in a variety of…

Under the Electrical Safety Act (QLD) the requirement is for all “new” Hazardous Area installations to have a Hazardous Area audit completed by an accredited Hazardous Area auditor and the installation found “compliant” prior to…

Hazardous Areas are present on many sites and are often overlooked, from our experience it has been noted that companies treat hazardous areas differently. Some examples; Do not know what hazardous areas are People equate…

Coex Training is partnering with The Apprenticeship and Traineeship Company (ATC) Bunbury to increase the delivery portfolio of post-trade electrical training in the South West region.   The ATC facility now includes dedicated training equipment…

When an alternating current is made to flow across multiple conductors of a transmission line where its spacing is large compared to their diameters, the air surrounding the conductors (composed of ions) is subjected to…

Mining boom or massive skills shortage? AMMA’s 2019 report revealed Alt. Combatting the skills shortage: 21,000 new mining workers needed by 2024 According to a recent report, the Australian mining industry will need 21,000 new…

Hazardous Areas. Not only are they dangerous, they’re increasingly common. And with Australia outsourcing more projects overseas, regulation has become challenging. So how do we ensure the next generation have the knowledge to work safely…