Changeover switch to allow use of either mains or wind power?

 


Hi, can anyone help me please?

I'm connecting a 2.5 kW WT to my domestic hot water immersion element
as its primary load, but need to switch the immersion over onto mains
power if there's no wind. The HW tank has a single immersion heater
element and no opportunity to add another (so I cannot have the easy
solution of one mains, one WT element). I reckon I need a double pole
changeover switch (i.e. double pole double throw) so that I can do
this; ideally I'd like to do this automatically with a relay, so if
there's no wind it switches to mains, but if there's windpower it uses
that as the default. I can see the diagram for it in my mind's eye,
electro-magnet and all, but my question is: is such a device available?

I'm in the UK where we use no-nonsense 240v mains electricity. (I
electrocuted myself when I was a wee boy, but fortunately lived in the
US at the time so I'm still here to ask this question.) The WT is
nominally 240V, but of course less than that at low wind speeds.

I've just dipped in to the NG, so apologies if this topic has already
been done to death.

 

Pig Sick wrote:

you can buy a double element i.e two elements brazed into one fitting .
there made for economy 7 systems with a single boss cyl . this allows
for the use of boost on old systems with separate white meter .
I think sadia heater make them .
also if in doubt consult a qualifyed electrician !
240 vac is dangerous and 240v dc is extreamly dangerous !

 



samc wrote:


AC is normally considered more dangerous since it tends to make ppl 'freeze'.

Graham

 

Pooh Bear wrote:


on a lighter note shorly you meen fry ?
my baseis for makeing the above statement is that grid ac passes though
0 volts reguly (all thought the peak is of cause higher than the nom
r.m.s value) of cause I may stand corrected . do I have evidence to back
my asertion up ? urr no . the above statement was more of a warning
about the dangers of high voltage equipment .

 





I wonder when it will freez ya ROYAL NASTY ASS cauz you definately deserve
it most