Electrical help needed, DIY, dimmaer wicthes blowing relays on my solar setup.

[sblezza]

Hi All,

I wonder if you can help me....

I've been designing my own solar solution recently and built a small example that worked really well. I've taken it into production and working with an electrician friend of mine, here is what we setup:

I have a solar panel connected (through a DC isolator) to an MPPT Solar controller charging 2 deep cycle batteries. I also have a Grid Tie inverter connected to the Solar panels after the isolator so when the batteries are full the excess goes to my house grid. This means while I'm out at work through the day the solar feeds my home grid and reduces the need for requiring power from my supplier.

The load out of the Charge Controller is always on and connects through another DC isolator to a 1.5Kw Inverter.

The Inverter connects to a double relay circuit on a time control circuit.

When the timer (230v mains) is "on" (ie. switch on within timer hours) it enables power on the 1st relay circuit which closes a 12v DC circuit which the inverters connects through and provides the 12v DC power to the input of the inverter, therefore turning it on.

The inverter when turned on outputs 230v to the 2nd relay circuit which switches my power from mains supply to the supply of the inverter.

The output of the timed controlled circuit and relays is connected directly to my Lighting circuits in my house.

So I'm basically running all my house lighting from batteries charged up by solar power and flick between mains power and battery power providing the 2nd relay has an input of 230v. If the batteries get low or the timer shuts off, we return to mains supply.

Everything was working fine and all wiring complete, then during the test phase we came across an issue. Everything worked in the house until it came to the main living room which has some standard B & Q dimmer switches.

When we turned them on we heard the 2nd relay vibrated or buzzed and then it stopped working. It looks like the 2nd relay was damaged by the dimmer switches.

I cant find anywhere as to why this would happen so was hoping someone on here would have some advice. My friend reckoned it could be something to do with the Phase control of dimmers but didn't understand enough to explain why because he works on big industrial stuff, not household.

Any advice would be much appreciated.

Thanks
Simon

 

[Wilko]

Hi Simon,
I have not seen this before, but as the dimmer is chopping up the incoming AC waveform to dim the house lights it may well be spooking the control circuitry in your invertor. Next step would be to bypass them. If that fixes it, then find some old fashioned rheostat based dimmer to use, if you must. When I want mood lighting I fire up the candles . Sounds interesting BTW, have you got a cot diag you want to share?
Cheers, David.

 

[Dan]

Don't mind me while I bump some threads in the solar PV forum. If they're not current or applicable topics, just ignore the threads; they'll drop off the page. If they are, feel free to chip in and chat solar stuff in the solar panels forum.