Does your switchboard keep you awake at night?

Did you know that New Zealand has more than 5000 house fires per year? And of those fires approximately 20% (or a 1000 of them) are caused by electrical faults. Older Auckland weatherboard houses in particular, are at risk of fire because they contain these old switchboards with re-wireable porcelain or ceramic fuses.

A switchboard that is outdated and in poor condition is not only dangerous but will lead to a compounding list of issues over time and this often leads to fires.

If your house was built before 1990 the chances of experiencing an electrical fire are significantly increased because it may contain porcelain re-wireable  fuses in your switchboard. The problem with porcelain fuses is their age and their ability to handle fault current. A wee lesson on fault current begins with a rating called the KA rating (or Kilo amps, meaning 1000 amps). This is the maximum amount of current that the fuse can handle before a complete meltdown or fire occurs. It should be noted that in a fault situation, current will increase exponentially and instantaneously. Now this is where it gets interesting. A porcelain fuse has a KA rating of 1000 kilo amps, where as a modern circuit breaker has a KA rating of 6000 kilo amps, for domestic installations that is. So essentially a circuit breaker can handle 600% more fault current than a fuse can. So, as was said before if your house contains re-wireable fuses, you’re fire risk is significantly increased ! Bear in mind the KA rating is not the amperage rating, it is the maximum amount of current that the fuse can handle before a complete meltdown or fire occurs.

A popular trick with homeowners before 1990 was to replace the blown fuse wire made of tin with a copper wire strand. The problem is that the copper wire does not melt in fault conditions, as it has a much higher melting point than tin. Using copper wire means the fuse will not blow and the problem just moves to another point, and the fault does not actually go away.

The modern home has many more appliances today, like televisions in every room, computers, phone chargers, gaming consoles (and we haven’t even reached the kitchen yet) which means modern homes have high demands on current. Switchboards before 1990 were not designed to cope with these increased demands and as a result, wiring in your home is more prone now to overheating, re-wireable fuses fail, connections become loose through over heating and fires start !

If you still have porcelain or ceramic fuses, it is likely that your switchboard has not been looked at for a very long time. This can lead to unknown issues that fester away all by themselves and you don’t even know.

Signs that your switchboard wiring may be faulty include:

  • The power keeps tripping.
  • Your lights are flickering randomly.
  • A plug socket’s are warm or even hot to the touch.
  • You smell burning particularly near the switchboard.
  • Frayed wire is a visible give away.

New switchboard technology is made with fire retardant plastics, and the phase bars (pathways for voltage) are made of metal, which helps protect against fire. In addition, modern switchboards have RCD protection which eliminates all of the old anomalies that fester away in older switchboards. RCD’s raises the bar by 10, as far as safety is concerned with modern standards.