What is Ripple Control or Off-Peak Supply ?
Ripple control is the most common form of load control, and is used in many countries around the world, including Australia, New Zealand, the United Kingdom, Germany, the Netherlands, and South Africa.
How does it work ?
Ripple control involves superimposing a higher-frequency signal (usually between 100 and 1600 Hz) onto the standard 50–60 Hz of the main power signal. When receiver devices attached to non-essential residential or industrial loads receive this signal, they shut down the load until the signal is disabled or another frequency signal is received.
How to recognize Ripple Control and other flickering problems ?
The easiest way to find out if the ripple control is causing the disturbance in the fans, LED's and other electrical equipment in the house is to find if out if this disturbance occurs at same time everyday. Ripple control comes on at the same time day.
If you are seeing the flickering at random times of the day, your electrical supply may be affected by other harmonics; a power fluctuation that is not part of the normal electricity supply or ripple control signal output. Harmonics are caused by an interference created by other equipment on the network, such as inverter type air conditioners and switch mode power supplies for computers.
Ripple Control in Australia
Electricity suppliers in particular areas of Australia such as NSW and QLD are injecting an off-peak ripple control signal onto their distribution networks in order to remotely control devices such as off-peak hot water systems and street lighting. In QLD this signal is 1050 Hz and in NSW it could be 750 Hz or 1050 Hz depending on your location.
Effects of Ripple Control
The unfortunate consequence of this control system is that electrical equipment connected to the mains supply is also subjected to this higher frequency signal and can have an adverse effect.
Such effects can present themselves as electrical noise or equipment malfunction, flickering or dimming of lighting circuits, and less commonly, audio noise induced in electric motors (e.g. ceiling fans) and audio/radio equipment.
In most situations this superimposed voltage level is low enough not to noticeably cause any problems.
In other areas where this voltage level is high (but still within the electricity supply parameters), the effects can be intolerable.
Solutions to Ripple Problem
The most cost effective solution is to buy an inline filter to block the designated frequency. Please note the filter would not completely block the frequency but will reduce the signal by 1/30th of the original level.
If the problem still persists, the consumer should check the strength of the signal being sent through their energy suppliers.
Other alternatives can be investigated if a filter is not enough..