Electric.ie May/June 2021

6 ELECTRIC.IE • The Magazine & Website for the Irish Electrical Industry • Phoenix Contact Surge Protection Device (SPD) Technology – Benefits & Best Practice! P hoenix Contact is a global leader in surge protection and is one of the largest manufacturers of surge protective devices (SPD’s) worldwide. The office in Ireland offers local support for design and applications and is backed up by significant resources from its headquarters in Blomberg, Germany. The IS10101 Standard The latest revision of the national wiring rules, I.S 10101:2020 has seen a welcome update to replace the ET 101:2008. Given that it has been 12 years in the waiting, and electrical installations have changed in the meantime, it is not surprising that there have been major updates. This is very welcome when we think about lightning/surge protection as the new standards offer a lot more clarity on the topic. Twelve years ago, a typical installation may not include Photovoltaics, LED lighting, LED televisions, home automation, heat pumps etc. etc. and while these are all very welcome advances in technology. They also bring with them new challenges due to the more widespread use of electronics which may make equipment are more sensitive. Important updates included in standard IS 10101 From a surge protection point of view, here are the main changes. • Part 443 – The main update to this section is the inclusion of a risk assessment method to establish a CRL (calculated risk level) for your installation. Good news is that you can avoid carrying out this calculation by installing an SPD. • Part 534 – the section has been significantly expanded and has a much-improved section on the selection of SPD’s according the installation location with more detail around practical issues such as the OCPD installation. • Part 712 – the section about PV systems, now includes requirements for protection against overvoltage’s and the selection of same. Practical tips regarding the installation: Surge protection is simple. Its function as a device is to control transient overvoltage’s in your electrical system and therefore keep your electrical supply voltage within the limits to which the electrical equipment was designed for. To select the correct SPD, you need to consider the following: • Installation location – Type 1 or Type 2 at the origin / main distribution e.g. Figure 1 - Type 2 or Type 3 at the sub distribution level and end equipment. • The voltage protection level (Up) – this is the maximum voltage measured during testing and should be less than 2kV* and never greater than the withstand voltage (Uw) of equipment it is connected to. See Figure 2. • The maximum continuous operating voltage (Uc) – the SPD must be suitable for the voltage of the supply system. • Expected short circuit current – the SCCR value of the SPD must not be less than the prospective short circuit current at its installation location. Installation: For an SPD to be most effective, proper installation is critical and the connected conductors (A+B+C) must be kept as short and straight as possible. The line length s hould be ≤0,5 mtrs. See Figure 3. • PE – Conductors used should not be less than; ¤ 6mm² copper for Type 2 SPD installed at origin ¤ 16mm² copper for Type 1 SPD installed at origin • Device protection should be installed as close as possible to the end device. Figure 2 : Equipment withstand categories in a typical installation Figure 1 : T1 & T2 SPD