Extensive range of LV AC, PV ( Photovoltaic ) and DC Surge Diverters and Surge Filters. Din rail, panel mount, hardwired and portable, Point of entry to final sub circuit. IEC Class I, II and III. UL type 1, 2 and 3



Surge protection for most data applications. Cat 5, Cat 6, Cat 5&6 POE, RS protocols, twisted pair control signaling, RF signaling, Video signaling.



AC/DC Switch mode power supplies. Din rail and panel mount. PDUs, cables and plugs to suit most many LV electrical distribution requirements.

We also offer advice to help you assess surge risk and recommend tailored surge power and data protection to suit your exact needs.



Surge Protection Fundamentals


What is a surge ?

A surge is a short duration excess of electrical energy in a system. It is also referred to as a spike, transient or impulse. Duration is usually in microseconds but even though this is very brief it can cause significant damage to electrical equipment. Surges can be caused by outside ( supply side ) and inside ( load side ) events. Outside events can be lightning, transformer switching and other abrupt supply side events. Inside events can be caused by air conditioning, welding, lift motors and other appliances with motors that create a sudden influx of energy. A surge can produce very high and harmful instantaneous voltages and currents. Electrical systems cannot absorb and control all of this excess energy before it gets to your equipment. And remember that it does not only affect AC circuits. DC supply, data, coaxial and signaling circuits are all affected by the same events through direct conductor exposure or cross coupling.


How do you prevent surge damage ?

There are devices called Surge Protection Devices ( SPDs ), that are designed to mitigate and eliminate this excess of harmful energy. SPDs come in all shapes and sizes but they all perform the basic function of absorbing and diverting the excess energy safely to earth where it is dissipated. Applying these devices to your electrical system however is not always straight forward. The characteristics of each installation must be understood to select the right SPD for the job.


What standards are there ?

There are many standards to consider and there is a hierarchy to observe. In Australia and New Zealand we have several standards to be considered including, but not limited to,  AS/NZS 1768 Lightning Protection, AS/NZS 3000 Wiring Rules and AS/NZS 3100 Electrical Safety of Equipment. On top of that there are International standards for the certification of the SPD itself. The most common 2 world standards are IEC61643-11 ( European ) and UL1449ed3 ( North American ). In Australia we have a preference for the IEC standards. However, products that meet or exceed these 2 standards are suitable for use in our local electrical infrastructure as we have no compulsory SPD certification standard in Australia and New Zealand.


How do I implement surge protection ?

By looking at a specific electrical infrastructure, standards can determine the degree of risk it has. It’s from this degree of risk and other electrical attributes of the system that the correct SPD can be selected and positioned for the job. In terms of the SPD certification standards there are basically 3 or 4 types of SPDs that can be applied. In IEC terms there are Class I, II, III devices. In UL terms there are Type 1,2,3,4 devices. In some applications it is necessary to apply SPDs in multiple locations to ensure a good result. The main aim however, is to place the correct class or type of SPD immediately in front of the equipment you are trying to protect so it absorbs and diverts the harmful excess energy before it reaches your equipment.


Types of SPDs.  Diverter vs Filter

A surge diverter does exactly that. It DIVERTS energy. In doing so it reduces the harmful voltage level but being a parallel connected device has limited ability to control the amount of harmful current flow. A Surge Filter adds other circuit characteristics. It adds capacitors in parallel and in some cases inductors in series as well. The effect of adding these components is to REDUCE NOISE and SURGE CURRENT to the load. So a 2 or 3 stage surge filter has all the benefits of a surge diverter ( limits voltage ) plus reduces noise ( attenuation ) and current flow ( inductance ). As a general rule the surge diverter is used as a primary protection device and the surge filter is used as a secondary protection device. However it is not always possible to use both in a single installation. The risk and electrical layout of an installation will determine the correct selection of a diverter vs a filter.


Due to the varying nature of every installation it is best to seek sound advice about which SPDs to use and how they should be installed
into your system.  NXT Solutions engineering personnel can assist you here - Please Contact Us.