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Hard wired surge protection Protection against equipment damage Home / Products / Hard wired surge protection

Hard Wired Surge Protection

A complete protection system for your home, business or building

lightning can deliver a surge that can literally blow electrical equipment apart

If you run or work in an industrial premises then a hard wired surge protector or transient voltage surge suppressor is the first layer of protection when it comes to protection against power surges and lightning strikes.

Transient surge protector for business and industrial premises

The amount of damage that can be created by a power surge or lightning strike is quite startling to most business owners. When a comparison of the cost of a surge voltage protection system compared to the cost of replacing electrical equipment and the lost hours within your business filling out insurance claims, waiting for equipment delivery etc.

Imagine losing all the equipment within your business for a moment. Not only do you lose the equipment, you can also lose the data that’s stored within it. Server information, emails, photos, business documents etc. Scary thought isn’t it?Call us today on 1300 795 160 to find out how we can help you with building surge voltage protection.

Whole House Surge Protection

More and more households are realising that the amount of electrical equipment they have is growing. With computers in almost every home, televisions, home theatre systems and the growing level of complexity of household electrical items, it makes sense to protect these from power outages and electrical surges.

Types of Power Surges

There are typically two types of power surges that can cause damage to household and industrial electrical items. These are:-

Direct Strikes

Whilst these are the most damaging, they’re also the least common. This is where lightning directly strikes a structure or cable feeding into that structure with the resulting energy finding its way to earth through the structure or equipment contained within.

Indirect Strikes

The effects of an indirect lightning strike can be more devastating as it may not be as obvious as a direct strike to the structure. This is where lightning will strike an object and the resulting EMF induces into all cable within a certain distance from the impact point. The induced surges travel down the cable until they reach an earth. This is normally through sensitive electronic equipment.

Remember, it does not have to be a direct strike to cause a major problem!

It is recommended that where there is a possibility of lightning strikes or industrially generated surges, that you contact Queensland Power Protection to evaluate your power protection needs. Queensland Power Protection will inspect your site, and offer recommendation on how to reduce and eliminate the risk of all lightning and surge problems and safeguard your technology. Our power quality testing service is also available at a nominal cost, this includes a comprehensive report to help in the selection of the best methods of protection for your site.


Many surges are caused by man, with industrial switching accounting for approximately 60% of all surges and transients. Lightning accounts for approximately 20% of surges and is by far the most spectacular.

Man made events

These include:-

  • Substation faults,
  • Internal "plant' equipment failure causing surges to other areas of the factory,
  • Inductive loads such as the starting of motors, generators and compressors. This has the potential to cause catastrophic PLC failure and transformer burnout.
  • Being located at the end of the grid which opens you up to large voltage variances, over and under voltage situations and general interference.

Natural events

These include all weather related events, earthquakes and tremors etc.

Other events

These are those events with no real known cause.

Surges and transients can gain access to your equipment via the following:-

  • Power Lines - Main power feed to the structure
  • Data/Signal Lines - Any RS232/422/485, 4-20mA loop, LAN cables
  • Telecommunication Lines - Phone lines, MATV, Satellite, etc
  • Poor earthing.


Power Lines

There are two types of protection available for the protection of Power Lines:-

  • Diverters
  • Filters


The Surge Diverter is the basic form of protection designed to divert to earth a large portion of the energy out of the incoming surge. Diverters can be mounted on the main switchboard or at distribution boards.

How do Diverters work?

A surge diverter main component is a Metal Oxide Varistor or MOV. These are connected in series with high-energy fuses. The MOV has a limited capacity and once that capacity is achieved, the MOV will move into a short circuit mode. The inline fuse senses this and blows taking the diverter into an open circuit or safe mode. The LED on the diverter extinguishes and the alarm, where fitted, will trigger. As with all of our product, this unit when it completes its job, will fail safe. As a diverter is connected in parallel, your equipment will not suffer a loss of power. All our diverters are rated for multiple pulse surges. This is where the incoming lightning surge is followed by up to 12 identical or smaller surges in a matter of milliseconds. Our 40KA diverter has been tested to withstand 17 40KA surges, 5 10KA surges and 2 2KA surges before finally reaching its capacity and going off line.

surgediverterInstallation: The Surge Diverter is connected in Parallel, which means that it is connected across the Active and Neutral lines. In the case of a Three-mode diverter, it is connected across the Active, Neutral and Earth lines.

Important Note: When installing a surge diverter, it is imperative to ensure the cable leads between the switchboard and the diverter must be as short as possible. The reason for this is that for every extra millimeter of lead length, an extra volt is added to the let through voltage due to the inductance of the cable. Therefore the normal let through voltage for a diverter is between 600 and 700V, and if the installation has lead lengths of 2 meters then the let through voltage will be 2600 to 2700 volts.


As a diverter is a parallel device, a filter whose first and third stages are diverters is known as a series device. This is where you have to cut the incoming cable and wire it through the filter. Due to this, the filter is rated to reflect the load rating of the equipment.

Earlier we explained that a diverter removes the energy from the incoming surge. The filter then modifies the waveform of the surge to a point that allows the power supply of the protected equipment to easily convert to its DC output without interference.

Surge filters should be used where sensitive electronics is to be protected such as:-

  • Computers
  • PLC's and control equipment
  • Audio and visual equipment
  • Telecommunications equipment


The filter is a three-stage filter:-

1.First stage: This comprises of either the LPI EDIN or LPI EMOV surge diverters which diverts to earth a majority of the energy from the incoming surge.
2.Second Stage: This comprises of a low pass series LC network that further attenuates the let through voltage and modifies the waveform.
3.Third Stage: This comprises of another diverter, which provides a final clamping function and cleans up any small transients generated by the load.

Normally a diverter is placed onto the main switchboard with a filter being placed onto the sub distribution board. There are three types of surge filter:-
1.Low Current
2.Medium Current
3.High Current

Low Current Filters:-

  • Available in 5, 10 and 20A versions
  • Single or three phase
  • Standard DIN rail mounted
  • Both Transverse and Common modes of protection
  • Full 3 stage filtering
  • Status indicator
  • Voltage free alarm contacts
  • Optional IP66 Enclosure
  • Standard 5 year warranty
  • Australian made and owned

Medium Current Filters:-

  • Available in 32 to 125A versions
  • Single or three phase
  • Back plane or enclosed
  • Both Transverse and Common modes of protection
  • Full 3 stage filtering
  • Status indicator
  • Voltage free alarm contacts
  • Optional IP66 Enclosure
  • Standard 5 year warranty
  • Australian made and owned

High Current Filters:-

  • Available in 200 to 2000A versions
  • Single or three phase
  • Back plane or enclosed
  • Both Transverse and Common modes of protection
  • Full 3 stage filtering
  • Status indicator
  • Voltage free alarm contacts
  • Optional IP66 Enclosure
  • Standard 5 year warranty
  • Australian made and owned

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