1. Surge Protection Devices
By Steve Kirby
Surge Protection Devices or SPDs are designed to protect electrical equipment from
Transient Overvoltages and they are becoming more commonly used in electrical
installations. It is important that electricians are aware of the functions of SPDs and
also the reasons for Section 534 in the current amendment of BS7671 Wiring
Regulations. http://personalsecurity.origingadgets.com/
Because of their short duration (around 350 micro seconds) transient overvoltages are
not picked up by MCBs or RCDs. They normally go unnoticed but can be a common
cause of problems which lead to a gradual degradation, faults and eventual failure of
electronic equipment. Lightning is usually the first thing that people think of when it
comes to electrical surges. A lightning strike can produce a current of around 100kA
and although it may only last for a fraction of a second can cause some serious
damage to an electrical installation. Surge Protection Devices are designed to divert
such voltages to earth very fast without interrupting the normal supply. BS 7671
Chapter 4, Section 443 covers the requirements for SPDs and where overvoltages may
occur from Lightning (Atmospheric) and Manmade (SEMPs) transients. Section 534
then gives the requirements and Appendix 16 contains diagrams of connection
methods. http://protectiondevices.origingadgets.com/
Risk assessments are the key to deciding whether Surge Protection is essential for an
installation. This may not be to do with how often overvoltages are likely to occur but
how much the user of an installation has to lose if a surge does occur. Generally SPDs
should be seen as an insurance policy against loss of valuable data, equipment and
property. http://selfdefense.origingadgets.com/
There is now an increasing amount of equipment being mounted on rooftops such as
Solar Panels, AC units and Communications Systems. Such installations may be
deemed to be vulnerable to overvoltages from lightning strikes and risk assessments
may recommend the installation of SPDs. http://electroshock.origingadgets.com/
Insurance companies could specify SPDs to protect valuable equipment and increase
premiums where they are not installed. This is why they may begin to be more
commonly used and even if electricians don't install SPDs as part of their main job,
they may come across them when carrying out inspection and testing or upgrading
existing installations. For these reasons alone it's worth being familiar with the
function and connections of surge protection devices within an installation as
specified in Section 534. http://spy.origingadgets.com/
SPDs can be fitted locally, as in computer or tv surge leads, but they are most
effective when used at the origin of an installation. For example it's not much use

2. protecting your tv from a surge if all the wiring in your house is burnt out!
http://pepperspray.origingadgets.com/
Further information about Surge Protection Devices can be found at the Surge
Protection Devices page of the UK Electrician's Blog Website
http://usb.origingadgets.com/