Purpose of an insulator is to prevent the unwanted flow of current from the energized conductor or conducting parts. Electrical insulation plays a vital role in every electrical system. An electrical insulator provides very high resistance so that practically no current can flow through it.

Insulating Materials

Basically, an insulating material or insulator contains a very small amount of free electrons (charge carriers) and, hence, could not carry electrical current. But, a perfect insulator does not exist, because even insulators contain a small number of charge carriers which may carry leakage current (negligibly small). In addition, all insulators become conductive when a sufficiently large voltage is applied. This phenomenon is called as insulation breakdown and the corresponding voltage is called as breakdown voltage.

An insulating material must have high resistivity and high dielectric strength. Additional desirable properties of an insulating material depend on the type of applications. The insulating material used for manufacturing insulated cables/wires must be flexible such as rubber or PVC. On the other hand, insulator used to support overhead power lines must be mechanically strong, such as porcelain or glass insulators.

Important Properties Of Insulating Materials

  • Resistivity (specific resistance) is the property of a material that quantifies how strongly the material opposes to flow of electric current. The resistivity of a good insulator is very high.
  • The dielectric strength of a material is the ability to withstand electric stresses without breaking down. Dielectric strength is usually quoted in kilovolts per millimetre (kV/mm).
  • Relative permittivity (or dielectric constant) is the ratio of the electric flux density produced in the material to that produced in a vacuum.
  • Electrical dissipation factor (dielectric loss) is the ratio of the power lost in the material to the total power transmitted through it. It is given by the tangent of the loss angle and, hence, also known as tan delta

Some of the commonly used electrical insulating materials are paper, mica, Teflon, rubber, plastic, polyvinyl chloride (PVC), glass, ceramic, porcelain etc.

Types Of Electrical Insulators

  • Pin insulators
  • Suspension insulators
  • Strain insulators
  • Shackle insulators

The above types of insulators are commonly used in overhead power lines.

Some more types of insulators are as follows

Post Insulators

A post insulator is more or less similar to a pin insulator. It has a relatively higher number of petticoats and rain sheds. Post type insulators are mostly used in substations, but in some cases, they can be used for overhead lines also. Thus, there is two types of post insulators: (i) Station post insulators and (ii) Line post insulators.

A line post insulator can be used for voltages up to 132 kV (pin insulators are used for up to 33 kV). Station post insulators are used in substations for low as well as very high voltages. For higher voltage levels, multiple station post insulators are stacked together.

Glass Insulators

Pin type glass insulators were earlier used in the 18th century primarily for telegraph/telephone lines. Use of ceramic and porcelain insulators spread in the 19th century. They proved superior protective properties than glass and become widely used. However, use of toughened glass insulators is becoming popular today. Unlike porcelain or non-ceramic materials, toughened glass never ages, and thus, offers a longer lifespan. Toughened glass insulator discs can be used in suspension insulators.

Polymer Insulators

Polymer insulators are composed of a fibreglass rod covered by polymer weather sheds. Polymer weather sheds are generally made of silicone rubber. Few other materials may also be used for weather sheds, such as polytetrafluoroethylene (PTFE or Teflon), EPM, EPDM etc. Polymer insulator is sometimes also called as composite insulators or silicon rubber insulators. They are almost 90% lighter than porcelain insulators and still offer almost equal or better strength.

Long Rod Insulators

A long rod insulator is basically a porcelain rod with an outside weather shed and metal end fittings. The main advantage of long rod design is the elimination of metal parts between the units, thereby increasing the insulator’s strength. Long rod insulators can be used at suspension locations as well as tension locations.

Stay Insulators

The insulator used in a stay wire (guy wire) is called as stay insulator. It is usually made up of porcelain and is designed so that in case of breakage of the insulator, the stay wire will not fall to the ground. It is also called as egg-type strain insulator.



If you want to do a bit of DIY in the home or see what may be wrong with your wires then you will definitely need to know what the different coloured wires generally mean. Although, we do highly recommend to leave these jobs to the professionals for safety reasons it is helpful to know the differences.

In Australia, we do things a little differently and a bit more complicated. Through the years the standards for colour coding have changed so depending on the age of your home, appliance etc. means that your wires could have different colours completely- especially for imported elements.

If you are in doubt with what your colours mean then contact the manufacturer if an appliance or consult a professional like us at Camtec!

In Australia, we currently have two separate colour coding systems, one for equipment wiring and one for installation wiring.

Equipment wiring includes things such as wiring in power cords. The list below outlines what the different colour codes mean for both single and multi-phased.

Current Australian colour code- Single phase

Active – Brown
Neutral – Light Blue
Earth – Green/Yellow

Current Australian colour code- Multiphase

Phase 1 – Brown
Phase 2 – Black
Phase 3 – Grey
Neutral – Light Blue
Earth – Green/Yellow

Old Australian colour code- Single phase

Active – Red
Neutral – Black
Earth – Green

Old Australian colour code- Multiphase

Phase 1 – Red
Phase 2 – White
Phase 3 – Dark Blue
Neutral – Black
Earth – Green

Installation wiring, also known as building wiring is for things such as the wiring behind power points and walls. The list below also outlines the different colour codes for single phase and multiphase in Australia.

Current Australian colour code- Single phase

Active – Red
Neutral – Black
Earth – Green/Yellow

Current Australian colour code- Multiphase

Phase 1 – Red
Phase 2 – White
Phase 3 – Dark Blue                                                
Earth – Green/Yellow

Neutral – Black

NOTE- The Installation colour codes are quite flexible – so caution is needed – actives/phases can be almost any colour – and are sometimes the same colour.

Below we have also included some of the more common colour codes used throughout the US and Europe in case you have imported appliances and wiring.

The US:
Single phase:
Hot (Live) – Black
Neutral – White
Ground – Green
Multiphase 120/208/240V
Phase 1 – Black
Phase 2 – Red
Phase 3 – Blue
Neutral – White
Earth – Green (Green/yellow or bare)
Multiphase 277/480V:
Phase 1 – Brown
Phase 2 – Orange
Phase 3 – Yellow
Neutral – Grey
Earth – Green (Green/yellow or bare)
Single phase:
Active – Brown
Neutral – Blue
Earth – Green/Yellow
Phase 1 – Brown
Phase 2 – Black
Phase 3 – Grey
Neutral – Blue
Earth – Green/Yellow


We hope that this outline of wiring colour codes helps you out in your home or business. However, we highly recommend any work that involves electricity and electrical currents be handled by a trained and experienced professional to ensure yours and others safety.

If you liked this blog please let us know by either leaving us a comment here or letting us know through our facebook page!


If your a DIY person or just want to be a bit more up with the lingo when your local sparky drops by you might want to know some of the basic electrical terms and concepts that they may use. Below are some of the key terms that you may want or need to know next time you have an electrical issue.

Alternating Current (AC) — An electric current that reverses its direction many times a second at regular intervals.

Capacitor — A device used to store an electric charge, consisting of one or more pairs of conductors separated by an insulator. Commonly used for filtering out voltage spikes.

Circuit — A closed path in which electrons from a voltage or current source flow. Circuits can be in series, parallel, or in any combination of the two.

Circuit Breaker — An automatic device for stopping the flow of current in an electric circuit. To restore service, the circuit breaker must be reset (closed) after correcting the cause of the overload or failure. Circuit breakers are used in conjunction with protective relays to protect circuits from faults.

Conductor — Any material where electric current can flow freely. Conductive materials, such as metals, have a relatively low resistance. Copper and aluminium wire are the most common conductors.

Current (I) — The flow of an electric charge through a conductor. An electric current can be compared to the flow of water in a pipe. Measured in amperes.

Direct Current (DC) — An electric current that flows in only one direction.

Frequency — The number of cycles per second. Measured in Hertz. If a current completes one cycle per second, then the frequency is 1 Hz; 60 cycles per second equals 60 Hz.

Fuse — A circuit interrupting device consisting of a strip of wire that melts and breaks an electric circuit if the current exceeds a safe level. To restore service, the fuse must be replaced using a similar fuse with the same size and rating after correcting the cause of failure.

Generator — A device which converts mechanical energy into electrical energy.

Ground — The reference point in an electrical circuit from which voltages are measured, a common return path for electric current, or a direct physical connection to the Earth.

Hertz — A unit of measure for frequency. Replacing the earlier term of the cycle per second (cps).

Inductor — A coil of wire wrapped around an iron core. The inductance is directly proportional to the number of turns in the coil.

Insulator — Any material where electric current does not flow freely. Insulative materials, such as glass, rubber, air, and many plastics have a relatively high resistance. Insulators protect equipment and life from electric shock.

Inverter — An apparatus that converts direct current into alternating current.

Kilowatt (kW) — Equal to 1000 watts.

Open Circuit — An open or open circuit occurs when a circuit is broken, such as by a broken wire or open switch, interrupting the flow of current through the circuit. It is analogous to a closed valve in a water system.


It’s generally an easy fix when your circuit breaker trips, but what’s also important to know is why it trips so that you can prevent it happening in the future.

In very rare cases your breaker may be faulty which causes the trip but in most cases, the breaker, or fuse is just doing its job when it pops. Our circuit breakers are designed to trip and turn off power when any of the following dangerous situations occur.

An overloaded Circuit

An overloaded circuit is the most common reason for a circuit breaker tripping. It occurs when a circuit is attempting to draw a greater electrical load than it is intended to carry. When too many appliances or light fixtures are operating at the same time, the circuit breaker internals heat up. Sensing this, the circuit breaker mechanism trips, breaking the circuit and shutting off the flow of electricity.

Short Circuit

A short circuit is a more serious reason for a breaker tripping. A “hard short” is caused when the active wire (red, white, blue) touches another active wire or touches a neutral wire (black). But sometimes a short circuit occurs not because of the circuit wiring at all, but because of a wiring problem in an appliance or device plugged into an outlet along the circuit. Short circuits, therefore, can be a bit difficult to diagnose and fix unless you have the correct test equipment.

Ground fault

Another type of short circuit, a “ground-fault,” occurs if an active wire comes in contact with anything conductive which touches earth (the ground). Ground faults can be especially dangerous when they occur in areas with high levels of moisture–like kitchens or bathrooms. There are steps you can take to identify and fix a ground fault, but also essential steps you should take to prevent one from occurring in the first place.


Now that we know why a circuit trips and how to prevent it in the future we can go into what you should do when your breaker trips.

In instances where you have an overloaded circuit it is really easy to fix you just follow our steps below:

  1. Identify your tripped breaker. Open your breaker box door and look for the breaker in the off position. Most breakers come with an orange or red marker indicating a tripped breaker. If there is no indicator, look for the switch in the off position. This is normally the breaker with a switch pointing the direction opposite the others.
  2. Flip the switch. Push the switch into the on position to reconnect your circuit and restore power. Regular power disconnections could be caused by other electrical issues. Call a professional if you’re experiencing routine breaker overloads.

In more serious cases such as ground faults or short circuits, you should definitely consult with a professional electrician. If you notice that there are regular outages, smell burning or notice signs of deterioration (such as scorching, rusting or corroding around you breaker) you should contact your local electrician immediately.

Ignoring electrical failure can result in fires and other home and life-threatening problems.Electrician-1968983


Office work can be visually demanding, particularly when it involves staring at a computer screen for an extended period of time. Lighting is one of the most important features of an office as it can have a major impact on productivity and levels of absenteeism.

Here are our top tips on how to make the most of lighting in your workspace.

Reduce high levels of absenteeism with good lighting

Artificial light sources cause glare or flicker on visual display units which are linked to many ocular-related complaints such as eye strain, blurred vision, dry eyes and headaches. Health issues caused by inadequate lighting are not restricted to the eye. It can also contribute to spinal complaints and other musculoskeletal injuries which occur when people adopt awkward postures while straining to read something under poor lighting conditions.

It can also be a contributing factor in offices affected by sick building syndrome, a term that describes high levels of absenteeism in a workplace thought to be linked to various environmental factors, so don’t allow lighting to become a health hazard in your office.

It is important to get the balance of light right in order to avoid employees developing health complaints. Lighting should provide enough illumination so that staff can clearly read printed or handwritten documents but not be so bright that it causes glare.

Levels of productivity can be influenced by lighting

Lighting can influence the efficiency of your employees. A study found that people who work in artificial light are more likely to feel tired towards the end of the working day, whereas those who work in natural light are able to continue working for longer.

Researchers have also found there is a strong correlation between exposure to natural light during work hours and sleep, activity and quality of life. Workers with windows in the workplace received an extra 173% white light exposure during work hours and slept an average of 46 minutes more each night. Those without windows had higher levels of daytime dysfunction.

Both studies suggest that to get the most out of your employees it is important to utilise as much natural light in the office as possible. This will increase the productivity of the workforce meaning the business can become more efficient.

How to ensure your office is suitably lit

A good visual environment will have sufficient light that provides good, but not excessive, good contrast between the task and the background. Overhead lighting can also be adjusted to prevent glare and flicker on monitors. Make sure they are dimmed to a level so that the room is still sufficiently illuminated without being too dark. Filters can also be used to diffuse fluorescent lighting.

Maximise natural light in the office by using an open plan layout and positioning desks by windows. Adjustable blinds can be attached to the windows if employees feel the need to adjust the lighting conditions.

It’s not just lighting that can prevent illumination issues. Matte finishes should be used on walls, floors and furniture to prevent glare. Computer monitor brightness and contrast can be adjusted according to the user’s preference. The monitor itself should be angled away from lights and windows.

Taking these prevention measures into account should ensure you have a happy, healthy and efficient set of employees.

Women in Trades


Having women in trades has always been an unusual thing to see here in WA. This is very unfortunate as the need for STEM jobs (Science Technology, Engineering & Maths) are increasing. Currently “between 2006 and 2011, it was estimated that jobs requiring STEM skills grew at about 1.5 times the rate of other jobs – by 14 percent compared to nine percent – and that demand for STEM skills is anticipated to continue” (DLGC 2015)

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When you think about emergency power options for your home or business, a backup generator probably comes to mind. This provides electricity independently from the grid when the power goes out.
All wired-in generators require a transfer switch to begin delivering electricity to your lights, appliances and electronics.

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All over the world, we have seen a growing concern in the changing climate. A very large part of the world’s emissions actually come from individual homes and actively reducing your amount of emissions can help us beat climate change!

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In your home, it’s increasingly important to understand things like meter boxes, circuits and fuses, especially if for some reason your power or appliances cuts out. In Australia, the standard voltage of electricity entering a home is 230 volts. The electricity poles that you usually see on the street carry electricity into each home to a service point. A service point is where the power flows through to connect to your meter box.

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