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APPENDIX A
Residual Current Devices (RCD’s)
Also known as Earth Leakage Protection systems an RCD is a protective device
that automatically disconnects the active conductors of a circuit when an earth
leakage current reaches a predetermined value.
Although RCD’s are mandatory in domestic installations, and in the final sub-
circuits of residential-type areas, the Australian Standards quote that the
requirement of an RCD does “not apply to a socket-outlet…..for the connection of
fixed electric cooking appliances, such as ranges, ovens or hotplates”
In installations that are neither Domestic nor Residential-type, AS/NZS 3000 2.5.3.3
states that RCD’s are needed only in situations where equipment may represent an
increased risk of electric shock to the user.
AS/NZS3000 2.5.2 gives the following warnings that should have been taken into
consideration when an RCD circuit was installed.
To avoid unwanted tripping due to leakage currents and transient
disturbances, care should be taken to ensure that the sum of the leakage
currents of electrical equipment on the load side of an RCD is less than
1/3 of its rated residual current
.
To avoid excessive leakage current causing unwanted tripping where
socket-outlets are protected by one RCD having a rated residual current
not greater than 30mA, consideration should be given to the number of
socket-outlets protected and the nature of electrical equipment likely to
be connected to the socket-outlets.
Tubular elements (such as those used in this unit) reaching temperatures greater
than 110°C are subject to moisture absorption and therefore earth leakage current
generation. Should the installation and use of this unit trip an RCD, the unit will
need to be run on a circuit without an RCD (as mentioned above) for approximately
30-60 minutes, after which time the elements should have dried out and the
appliance should function normally. If you are unable to locate a circuit without an
RCD please contact your supplier, or if you prefer you can contact Roband and
send the unit to one of our offices where we can run the appliance on a suitable
circuit free of charge (a return freight charge may apply).
