The intermittent flickering of LED lights


Ripple Control Explained

Ripple control is a way in which electrical companies use a superimposed frequency on standard 50Hz AC power supplies, which are commonly found in most (if not all) New Zealand households. You must be asking yourself now, “but what does this mean??”

Simply put, electrical companies are controlling and managing off-peak power load on their distribution networks. The frequency is used to control hot water heaters, street lights and water pumps through their remote receiver to control the power going to and from each utility. Ripple control may also be used to signal high network load periods for major customers to allow them to reduce power consumption.

What are its Effects?

A flickering LED light is the most common complaint arising from ripple control, which is generated when usually but not only when the light is dimmed and the ripple control frequency is in the line, usually between 300Hz and 1300Hz. The flicker is often, but not always, intermittent depending on when the ripple control signals are being transmitted. It is normally at certain times i.e. 6pm and then again at 8:30pm and will only last for 30 seconds to 2 minutes, and when the power company stops sending the signal the flicker stops. People often notice it most acutely in the night when off-peak hot water systems are turned on. ALL brands of LED drivers are affected by these ripple control signals.

How will I be Affected?

Ripple control frequencies are commonly used in NSW, south east Queensland and New Zealand, although other areas within Australia also use this technology not all properties are affected by ripple control, so just because you might live in one of these areas, does not mean that you will have these problems.

One of the only ways to confirm if the area you live in is affected by ripple control frequency is to contact your power company and ask them directly. If you have a system that uses ripple control signaling you might also see a ripple control receiver wired into the fuse box and a dual tariff meter or dual meters.

NOTE: The presence of a ripple control signal doe snot necessarily mean you will experience ripple control flicker in your LED lights.

What can be Done About the Flicker?

Ripple control signal filters are available to manage the flicker generated by affected LED lights. The ripple control filter must be matched to the local signal being output by your electrical company, usually 750Hz or 1050Hz (information of which can be acquired through your electrical company), and must be installed by a licensed electrician.

There may be extreme cases where the ripple control frequency is so strong it requires two filters to be installed to reduce the flicker sufficiently and in some locations multiple ripple control frequencies are used also requiring multiple filters.

Why Doesn't Martec have Ripple Control Filter's in their LED Drivers?

Ripple control is not the norm and in many environments. While Martec does sympathize with the few customers who do experience a problem, it is not cost effective to build an Electronic Driver that rejects all ripple control frequencies given the small proportion of people affected, a cost that would have to ultimately be borne by all customers.

It's not Ripple Control Noise. What Else Could it Be?

If you are seeing the flickering at random times of the day, your electrical supply may be affected by 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.

the offending appliances may be in your home or other premises on the local power grid. If you are being affected by network harmonics, it may be of benefit to transfer the electricity supply to your premises to a different phase in the street. This is something you will need to discuss with your electrical company.

if the flickering is cause by an issue with the dimming mechanism rather than the ripple control, the diagnosis of this issue is totally different to ripple control, as if the dimmer is causing the flickering or instability, normally this will happen when the dimmer is on a very low setting and after a while the flickering begins and does not stop, until the dimmer is adjusted to full power, sometimes this can be stopped by not going right to the minimum on the dimmer but just above it.

Will my Warranty Cover Ripple Control or Harmonics?

Ripple control and electrical harmonics flickering is not the result of a fault with your LED light or dimmer fan. As such we do not cover either occurence under out warranty. Where ripple control flickering is found to be at fault, the customer will have to acquire a filter and have it installed by their electrician at their expense.

If you make a warranty based service call and ripple control or electrical harmonics flickering is diagnosed as the problem you may be charged the call-out fee for the electrician. Ripple Control affects all brands and types of dimmable LED lights.