As mentioned in the previous edition, the next few blogs will address the safety aspects relating to installation of the distribution board.
The focus of this blog is to highlight some of the regular “wobblies” which I have witnessed in my many years of service in the electrical industry.
All too often, when property has “changed hands”, one of the first points of action is to carry out renovations to support the desires of the new landlords.
Regrettably, finances tend to limit the available budget and that is when “short cuts” become a problem – particularly regarding the safety aspect.
Location of the Distribution Board
It is prudent to have the electrical distribution board located in a central position in relation to the respective electrical outlets.
The boards are available in either metal or a non-flammable material.
It is preferable for the distribution board to be enclosed with a metal, hinged
door.
Regrettably, most distribution boards are not very attractive and are
usually hidden behind a wall hanging.
The board must be readily accessible and installed between 1.2 and 2.2 metres above the floor level.
In several installations, I have witnessed the distribution board “tucked away” between the shelves in a cupboard.
To gain access to the circuit breakers, the shelves have to be cleared and in some
cases removed in order to open the distribution board cover.
Imagine the unnecessary stress created in the event of an electrical emergency!
A distribution board is not allowed to be installed in a bathroom and must be at a minimum distance of one metre from a water outlet.
In the case where distribution boards are installed externally and are exposed to the elements, weather-proof distribution boards complete with a suitable door must be employed.
Furthermore, in the case of surface-mounted distribution boards, all electrical conduit wireways and cables must be installed so that the entry into the distribution board is via the base of the unit.
Any cable entry via the top or the sides of this distribution board renders the installation non-compliant with the required weatherproof safety standard.
The use of water-resistant sealant’s do not make the installation compliant – the only way is to install the cable entries correctly!
The distribution board is not allowed to be installed above a fixed cooking appliance or in a position where a stationary cooking appliance could be put below it.
This requirement makes a lot of sense as the ingress of cooking oil will
ultimately render the circuit breakers non-operational.
Imagine the stress and difficulty experienced in the event of something catching alight on the stove!
Recently I have witnessed a certified electrical installation where a gas stove
is installed immediately beneath a distribution board! So much for safety.
Distribution Board Circuit Labelling
Unfortunately, this is one vital aspect of electrical safety that is all too often over-looked.
Over the years I have developed a simple and very practical method of circuit labelling which I will now share with you.
Start off by drawing a simple plan view of your dwelling and label the respective rooms.
Draw up a simple symbol legend that relates to each of the electrical elements – these are the light switches, plug points, shaver plug point and stove isolator.
Insert on the plan the symbol of each electrical device in every room.
Label all the circuit breakers in the distribution board numerically from left to right 1, 2 … to the last circuit breaker.
On a sheet of paper, draw up a table of the circuit breakers from the first “1” to the last number.
With the co-operation of a family member, set about identifying the control of each circuit breaker.
For the plugs, use a portable appliance – switch it on and then switch off the respective circuit breakers, one at a time, until you identify the circuit breaker controlling that particular plug point.
Record the number of the circuit breaker.
Using a marker and masking tape, label the plug point with the number that relates to the circuit breaker concerned.
Record the circuit breaker number on the plan view of the dwelling.
Identify the light switch circuit breaker by switching on the light switch in a particular room and then switching off the various circuit breakers at the
distribution board to determine the controlling circuit breaker. Repeat
this procedure for each light switch.
To identify the stove circuit breaker, switch on a particular plate or the oven and ensure that the indicator light on the stove is “on”.
Then repeat the same process as in “item 8” above to identify the controlling circuit breaker.
Upon completion, append a copy of the circuit legend (item “5” above) on the distribution board.
Using a permanent marker, label each and every electrical outlet according to the legend and plan.
Note During the circuit breaker identification
process, do not switch off the main switch or the Earth Leakage Circuit
breaker.
Now the interesting point becomes apparent – look how
many plug points are on controlled by the same circuit breaker!
Well that’s all for this edition.
The next “blog” topic of concern will be a continuation of the electrical distribution board during which we will address the segregation of respective circuits, mixed circuits and the need for sub distribution boards together with the associated circuit numbering.
Cheers for now
Tony Murdoch
