load shedding fix

**ians** · 01-Feb-20, 08:38 AM

I have 3 inverters installed in parallel which supplies a house with 2 outbuilding....3 geysers ...entertainment area ...pool pumps etc.

All connected to a 60 amp single phase supply.

Here's the challenge ...geysers ...pool pumps and other non essential supplies... they drain the batteries too quickly.

I need a solution to this problem... i could run control wires to each device and fit a contactor or relay ...the problem is the distance and access to the various locations...something like the old ripple relay system the municipality used back in the day.

The other thought was to fit wireless unit ...like a sonoff ...a receiver...wifi unit or even bluetooth to control the device when the power turns off.

It sounds simple however ...each item is fed via a sub DB with a pre paid meter which has other stuff like fridges etc.

What i am looking for a simple wireless solution to control these devices without having to separate them from the sub DB they are connected... there was an attempt to separate them via the main DB ...however this no longer works because the sub DBs now have prepaid meters.

Power goes off...a signal is sent to all the devices to shut down and when the power is back on... a delay staggering the power on to each device ...preventing a heavy load on the system.

**GCE** · 01-Feb-20, 09:44 AM

Hi Ians

Can you adjust the frequency output of the inverter ? if so then you could increase/decrease the frequency with mains fail and use a frequency monitor to drop a relay out
I know ACDC do a monitor at list price of R 297.00 - I am sure others do as well

https://www.acdc.co.za/pages/product...l?FR1%20230VAC

**ians** · 01-Feb-20, 06:13 PM

GCE thanks for the suggestion.

I have spoken to a few people and there were many suggestions ...but the one i am thinking of doing is the solid state relay option ...will go into more detail when i get a chance..everyone is waiting for dinner.

**adrianh** · 01-Feb-20, 07:02 PM

Why don't you faff with RaspBerry PI or ESP2866 IOT devices. You can build a IOT WiFi network with GSM backup fairly easily.

**ians** · 02-Feb-20, 11:38 AM

I was thinking wireless ...but i think it might be better to run a low voltage control wire and use solid state relays to switch the devices off.

This also brings a few challenges... solid state relays are not designed for long on/off periods more short fast switching... then we have the heating to take into consideration.

My thoughts are to use a high current rating SSR to switch the devices which will draw around 10 - 15 amps ...wired via the timer for the pool pump and the thermostat on the geysers.

**Rifrug** · 02-Feb-20, 07:19 PM

Hi Ians,
The sonoff switches are great and cheap thats if you have wifi for them, can be a bit of a challenge if distance is too far.
Sonoff could control pool pump and geysers and be scheduled to come on during the day only with good PV and set the timers so that pool and geyser does not come on say after 17H00 to save battery power.
I have mine wired in such a way that the inverter powers the sonoff, in other words only when I am off-grid do the sonoffs function because they then control my loads. When my grid power is back on the sonoffs does not have power so they then have no effect over my loads and everything work as normal.