# Interest group forums > Electrical Contracting Industry Forum > Electrical Load Shedding Forum >  Ripple Control Relays

## rohor

In 1994, my new Townhouse when I lived in Midrand, had an odd "box" just outside the front door. On enquiring with the complex electrician, he advised me that it was designed for a ripple control relay. 

This was apparently a device that could be used by the Local Municipality, to switch off just the geysers in a suburb, to prevent maximum demand charges.

It might only be necessary to shed the geysers for 15 or 20 minutes, which would have absolutely no effect on hot water, but have a huge reduction on power demand, given that the average geyser is 3Kw per house.

Went back to have a look. Box still there with loose wires.

What ever happened to that simple principle of load shedding, without the need to shut down a suburb completely.

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## duncan drennan

I know that in Gauteng these are widespread and I think that it is mandatory for new installations. There are plenty of people all over the country that have them installed.

Who else has experience with these?

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## Graeme

In Durban, many years ago, the City Council fitted ripple relays to houses in Durban North.  Alas, the scheme collapsed because light aircraft wishing to land at Virginia Airport would radio in for landing instructions, the transmission would get picked up by the overhead electricity reticulation network, and the frequency was such that it would set off or on all the ripple relays.  We still have ours in our distribution box and it intrigues any electrician we may call from time to time.

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## OldGoat

> I know that in Gauteng these are widespread and I think that it is mandatory for new installations. There are plenty of people all over the country that have them installed.
> 
> Who else has experience with these?


In the far East (Benoni), we have ripple relays installed. You can hear the contactor switching on and off.
They switch the geyser off for about an hour at a time and I have never had cold water (although some have complained).

There is a drive from Eskom to have these relays installed in all houses.

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## rohor

I notice in the Star today, that the ripple control relays, are the big saviour for Gauteng.

Question is why did it take so long.

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## jacques71

Hi, i am  a South African Electrician living in New Zealand.I have been introduced to Ripple Relays when i started working in NZ and find them useful but also a pain in the you know where.They control our streetlights and hotwater (geysers)These relays get send signals from ripple plants in our substations and activate on these signals.There are areas where the signals dont activate relays and we then have to wire in a photocell or daylight switch.

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## ians

> In Durban, many years ago, the City Council fitted ripple relays to houses in Durban North.  Alas, the scheme collapsed because light aircraft wishing to land at Virginia Airport would radio in for landing instructions, the transmission would get picked up by the overhead electricity reticulation network, and the frequency was such that it would set off or on all the ripple relays.  We still have ours in our distribution box and it intrigues any electrician we may call from time to time.


I am looking for one of these ripple relays or just a picture of it.

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## Justloadit

> I am looking for one of these ripple relays or just a picture of it.


See this web page halfway down

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ians (15-Mar-20)

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## AndyD

There's more modern units available as well nowadays.FMX-500-TS.0007.02.EN-06-2017-web.pdf

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## SOLARWIND

Ripple relays were quite common in the 80's, especially in Gauteng and Vaal Triangle.
Surely, they can be introduced again, which will allow ESKOM or whoever else to turn off all geysers whenever needed. At least will this be a way to keep the lights on during load shedding! The control need not come superimposed on the power lines, but rather over the Internet.

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## Justloadit

> Ripple relays were quite common in the 80's, especially in Gauteng and Vaal Triangle.
> Surely, they can be introduced again, which will allow ESKOM or whoever else to turn off all geysers whenever needed. At least will this be a way to keep the lights on during load shedding! The control need not come superimposed on the power lines, but rather over the Internet.


Not every one has an internet connection at home.
Besides there must be a way to insert the network and pass word by the home owner, who will most probably disable the device.

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