Solic immersion diverter on grid tied solar system causing buzzing ?

[MoreWellie]

I have been helping my son install a grid tied system and the last bit that has been put in place today was a solic box to divert excess generation into an immersion heater to maximise the local use of generated energy

he now says that whilst it is working he can hear buzzing from both the hot water tank end and the fusebox which are widely separated

I can get my head around the idea that an immersion may buzz if fed with chopped up mains supply (I believe the solic only diverts the excess power not a full 240v feed) but was struggling with a reason why the fusebox would

Anybody have any experience that might suggest why the breaker might do so?

 

[brightspark]

emersion heaters sometimes hum what size breaker is it

 

[MoreWellie]

16amp

 

[brightspark]

could try transferring in db to another breaker temporary see if it still does it

 

[MoreWellie]

Good idea, definitely worth trying, thank you

 

[Gareth J]

They're very electrically noisy. I've got one, on a completely different phase, the solic unit is 50m from the house and the immersion is a bi noisy. But it also induces noise in a sorts of household stuff. Induction hob, thermostats, the voltage smoother (or whatever it is) that tidies up the electric feed in the back of the washing machine.

Have created workarounds for most of the annoyances but there must be some kind of issue. I suspect something funny is happening via earth and an induced frequency. The actual wires are completely separate from anything else in the house.

Let us know if you find a cause/solution!

 

[Martin-Sy]

We've had an Apollo GEM since 2016.

Which has (touch wood) behaved flawlessly and without troubling electrical or audible noise (see below).
It can control two loads with a settable priority. In our case first priority is the immersion heater.
Second is a 3kW convector heater in the garage/workshop.
Installation was done with a temp sensor on the hot water tank so you can set the desired temp rather than wait until the thermostat in the immersion cuts out.

When the convector heater is on at partial load you can just about hear it, but it's not really a buzzing.

 

[Islander71]

I had to get rid of the diverter I fitted - cannt remember the make. It used pulse width modulation to vary the current into the immersion heater, which I guess is firing very short and rapid bursts of current at 240v into the immerser. It caused havoc with the elderly "Windy Boy" synchronous inverters fed by a 5Kw wind turbine, quickly causing them to make a horrible buzzing noise then shutting down. I believe there was an analogue diverter made which while much more expensive, got round this problem.

 

[Gareth J]

I had to get rid of the diverter I fitted - cannt remember the make. It used pulse width modulation to vary the current into the immersion heater, which I guess is firing very short and rapid bursts of current at 240v into the immerser. It caused havoc with the elderly "Windy Boy" synchronous inverters fed by a 5Kw wind turbine, quickly causing them to make a horrible buzzing noise then shutting down. I believe there was an analogue diverter made which while much more expensive, got round this problem.

Odd, the noisy solic I have is fitted right next to a windy boy on a 5kw turbine. It suffers a bit from buzzing but nothing outrageous and doesn't seem to be a problem for the inverter. An iboost on another phase is much less noisy.