What is a safety switch?
A Safety Switch is an RCD
(Residual-Current Device) that protects your home and family members
from fire and electric shock.
a safety switch is a life-saving device which is designed to
prevent you from getting a fatal electric shock if you touch something
live, such as a bare wire. It can also provide some protection against
The Australian Standards
states that all power and lighting circuits must be protected by a RCD
and that there can only be 1 light and 1 power circuit on one RCD.
Parkers Electrical NQ recommend that you
install 2 poll or 1 poll RCCB
, these are a CB & RCD in one
unit, Parker's electrical NQ can install or upgrade your safety switches
for you and to the current Australian Standards. We use all RCCB on
Power and lighting circuit in our
There are many types of safety switches, we are going to cover the most common ones and
recommend what type is best today.
This is a 2 Poll RCD and is often used to
protect 1 or many circuits, the use of this type of RCD is out of date as
regulations have changed.
The disadvantages are
1) If one circuit is faulty then you lose all your circuits.
2) If protecting 1 circuit this is a more expensive way of doing this.
This is a 4 Poll RCD and is often used to protect 3 phase circuits
or many single phase circuits, the use of this type of RCD is out of date
as regulations have changed.
The Advantages are:
1) Often the only way of protecting 3 Phase circuits.
1) If one circuit is
faulty then you lose all your circuits.
This is often a more expensive way of protecting your circuit.
This is a 2 Poll RCCB, it looks the same as the 2 poll RCD but it is a
RCD and a CB in one unit, This is one of the recommended ways of
protecting your circuits and complies with the Australian standards. All
Lights & Power circuits must be protected with one of these.
1) If a circuit is faulty only
that circuit is effected.
2) This is often
the cheapest way to protect your house.
This is a 1 poll RCCB this
is a same as the 2 poll RCCB that only takes up 1 spot instead of 2. This
is one of the recommended ways of protecting your circuits and complies
with the Australian standards. All Lights & Power circuits must be
protected with one of these.
The Advantages are:
1) If a circuit is faulty only that circuit is effected.
2) This is often the cheapest way to protect your house.
3) You can fit more circuits in the switchboard which means a smaller
How they work:
|| A RCD measures the deferent between the current on
the active and neutral wire, if the deferent is greater then a set amount
usually 30 milliamps (0.003 Amps) the RCD will trip out. The missing
current cold be leaking of to earth by a fault in a device or through a
person being in contact with the active cabile. The RCD will trip in less
then 30 millisecond (0.003 seconds)
A RCD has a amperage
rating, A RCD will not trip out at its maximum amperage, infect if the
draw on the RCD is greater then the amperage rating it will damage the RCD
and may not work correctly.
A RCCB is the same as a RCD
with one big deference it is also a Circuit Breaker, this means that the
amperage rating is the same as having a CB or fuse, this means that the
RCCB will trip if their is a current leak or the circuit is over loaded.
Parkers Electrical NQ can install or test RCD's in you're house for you.
In the AS/NZS 3000-2016
||Clause 188.8.131.52 stats RCD's are recognized as a means of
providing automatic disconnection of supply in accordance with
184.108.40.206 Protection by automatic
disconnection of supply
||Disconnection times. The maximum disconnection time
for 230/240 V supply voltage SHALL NOT
exceed the following.
||0.4 s for final subcircuits that supply:
||socket-outlets having rated current
not exceeding 63A (lighting is classed
as a socket outlet)
||hand-held Class 1 equipment; or
||portable equipment intended for
manual movement during use.
||5 s for other circuits including submains
and final subcircuits supplying fixed or
Clause 220.127.116.11 stats RCD's for the limitation of earth leakage
current SHELL be capable of interrupting the part of the circuit
protected by the RCD when an earth leakage current reaches a
RCD's shall be installed for additional protection of the
|| All Socket Outlets, Lighting Points
& Hand Held equipment.
|| Some Wiring systems as specified in Clause
18.104.22.168, we will not go into this.
|| Electrical heating cables as
specified in clause 4.10.5, usually not used in north Queensland.
|| Electrical equipment, including socket outlets, installed in damp
|| Installation requirement for deluge showers
|| Showers Zone 1 further
clarified for different shower head
|| Fixed water container size of 40L.
|| Spa pools and tubs water capacity clarified
per applicable standards.
electrical installations as specified in AS/NZS 3001, AS/NZS 3002,
AS/NZS 3003, AS/NZS 3004, AS/NZS 3012 & AS/NZS 4249.
in areas where excessive earth leakage current
could present a significant risk in the event of failure of other
measures of protection or carelessness by users, RCDs are designed to
provide additional protection against the effects of electric shock by
automatically disconnecting supply before serious physical injury can
Written by Gary Parker
25 December 2016
©Parker's Electrical NQ. You have the right to use any part of this
article as long as you credit it to Parker's Electrical NQand
link back to this article using this link SAFETY
SWITCHES BY PARKER’S ELECTRICAL NQ