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Excess solar to heat water


viper_za

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4 minutes ago, superdiy said:

I LOVE that heatsink, but how many watts does that thing dissipate? More than your daily PV generation?:D:D

Works very well in winter and now I know why last year was so hot. :rolleyes:

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8 minutes ago, superdiy said:

Feel free to ask before you buy anything. :)

Will do thanks

My friend also just sent me a whatsapp video turning the bmv relay/contact on and off connected to multimeter showing 0 volts.

It is actually just a damn smart switch

 

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1 hour ago, The Terrible Triplett said:

Seriously, can we get consensus on what is the best relay to use on a BMV to switch on geysers, stoves, poolpumps and anything else you want, that is smaller? :D

https://www.robotics.org.za/index.php?route=product/product&search=Solid+State+Relay+&description=true&product_id=1335

And if I find ONE person using a Finder ... :D

.So a BMV driving a 230V contactor. They need to change their manual

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1 hour ago, The Terrible Triplett said:

DELETE please.

I have to agree with TTT this has been the biggest waste of time - Plonky Blue Power gets -10 points for manual inaccuracies. Mind you, I need to wind my neck in, Voltronic would be minus so many points they would not be allowed to play.

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4 minutes ago, Chris Hobson said:

So a BMV driving a 230V contactor. They need to change their manual

I did mention such to them. But, if it was me, i would keep it on 60v/1a to keep people like me away from tampering too much. :D

Must say, after all this, suffering nearly 10 near heart attacks, I am quite the happy chappy re. the BMV relay now ... and my Finder relay's. :P

Victron just builds good stuff.

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Chris, what I find very comforting is the speed at which Victron got back to me, today and on previous occasions.

That gives them +20 in my book, 10 more to contra your -10. :D

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40 minutes ago, The Terrible Triplett said:

I did mention such to them. But, if it was me, i would keep it on 60v/1a to keep people like me away from tampering too much. :D

Must say, after all this, suffering nearly 10 near heart attacks, I am quite the happy chappy re. the BMV relay now ... and my Finder relay's. :P

Victron just builds good stuff.

Okay let's see if I understand it correctly.

I think the 60v they have is correct and what it means is you can run up to 60vdc through the BMV relay

This example uses 12vdc

temp relay.JPG

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Just been reading the Victron Quattro Manual that I downloaded some time ago and there i saw the following info on the relay in question:

"5) Programmable relays which can be set for general alarm, DC undervoltage or genset start signal function
AC rating: 230V/4A
DC rating: 4A up to 35VDC, 1A up to 60VDC"

So Victron gets its 10 points back?

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Okay, finally had some time to go through this.

I decided to add a small DB to be installed next to the geyserwise controller to house the relay and the CB for manual control on bad PV days

1 Geyserwise controller + thermostat: http://www.geyserwise.com/products/geyserwise/geyserwise-tse

2 Geyserwise 1500w element: http://www.geyserwise.com/products/elements/1500w-ac-element

3 Relay: http://za.rs-online.com/web/p/non-latching-relays/7083184/

4 Relay DIN Rail socket: http://za.rs-online.com/web/p/relay-sockets/2723137/

5 Relay Isolation coil to contact: http://za.rs-online.com/web/p/products/6668019/?sra=p&r=t

56e2ad699cacc_GeyserWiring.thumb.JPG.12b

You will see that the Thermostat will always have power as this will ensure the geyserwise does not give an error.

What I can also probably do is connect the normally closed cable from the relay to the underside of the CB saving some work.

Please let me know what your thoughts are on this

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The BMV relay can handle 60V, 1A. I use relays like this to drive 220V, 5A pumps directly from an ardiuno: http://www.communica.co.za/catalog/Details/P1651500292 This one can handle a 220V, 10A load. I guess, if 10A isn't sufficient a similar PCB design can be done with a 20A relay instead. 

 

If you open up the geyserwise boxyou'll find a similar relay inside, switching the geyser element on and off. Get the product code and let's build a small PCB for it, should cost maybe R100-R200 

 

Or you can use a Solar State relay instead. It's just much more expensive. 

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Hi Guys,

I am no electrician, but... What exactly is the function of the GeyserWise? Does the geysers existing thermostat not control the temp? And can we not use a  timer to ensure it only gets power between certain times? Or am i sitting the pot miss here?

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I just discovered an interesting device:

http://ginverter.com/html/2016/01/29/20160129030223580003188.html

Growatt Solar MeBoost

The Solar MeBoost is designed to be used in conjunction with solar PV system, where surplus energy generated canbe stored within a domestic hot water cylinder in the form of hot water.

No idea of cost or anything more than I read in this page.

However tomorrow I have a meeting with these guys and I will ask more details.

Another but unrelated cool gadget:

http://ginverter.com/html/2014/01/16/2014011601132644293434.html

 

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On 2016/03/15 at 10:50 PM, MaurizioZA said:

I just discovered an interesting device:

http://ginverter.com/html/2016/01/29/20160129030223580003188.html

Growatt Solar MeBoost

The Solar MeBoost is designed to be used in conjunction with solar PV system, where surplus energy generated canbe stored within a domestic hot water cylinder in the form of hot water.

No idea of cost or anything more than I read in this page.

However tomorrow I have a meeting with these guys and I will ask more details.

Another but unrelated cool gadget:

http://ginverter.com/html/2014/01/16/2014011601132644293434.html

 

I followed up at the Solar Show.

Growatt Solar MeBoost is not in production yet. At Growatt stand they did not know much about it except it will only work for the grid-tied inverters.

"Good" I said "then they will work  with your Growatt 3000HY, Growatt 5000HY and Growatt 10000HY (which are equivalent re-branded Infinis but at double the price)" they replied they wouldn't since the hybrid are not grid-tied. I showed them their brochures stating that these are grid tied and then someone said "maybe but the Solar MeBoost is very expensive". How expensive? Nobody knew.

Upon inquiring about the "cool gadget" I received similar answer.

I gave up. These sales people have no clue.

When I have have time I will follow up by mail.

Growatt was a frustrating and depressing stand. No comment about Tesla.

Interesting stand at Must where they have released their Axpert clone with a grid-tied option. Good value for money for a 4Kw grid-tied but the 145V max PV and the 3000W solar charger are the limiting factors.

I managed to convince a friend that an agreement to stock Oliter batteries was worth a try: he will be running tests to check if those impressive specs (13 years expected life, 572 times 100% DOD) match reality. Although slightly worse than Lead Crystal those specs are still very impressive and the batteries look sexy ;)

I am happy that Oliter engineer has recommended battery values to enter in the Infini set up (which they also use in their "Energy Storage Systems"). I used them last night and they worked much better than what I had previously used (but I still have to re-calibrate the inverter battery values).

Interesting day ;)

 

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On ‎3‎/‎15‎/‎2016 at 10:37 PM, Valken said:

Hi Guys,

I am no electrician, but... What exactly is the function of the GeyserWise? Does the geysers existing thermostat not control the temp? And can we not use a  timer to ensure it only gets power between certain times? Or am i sitting the pot miss here?

Hi Valken

Yes it is like a timer but with more control and safety features.

The Geyserwise uses it's own thermostat replacing the existing one you have.

Just a few features that stand out

  • Clear display of water temperature, time, day, heating mode and malfunction conditions (nice to not guess the temperature)
  • Easy temperature setting to your requirements (30 - 65°C)  (no need to climb into the roof)
  • Four different temperature settings (different temps for different times of the day if you want to)
  • Daily programmable timer with four time settings (Not sure if the normal timer can also have 4 schedules a day)
  • Electronic thermostat with mechanical thermal cut-out at 90°C.
  • Dry heat detection - empty cylinder. (happened to me before)
  • Temperature probe failure detection for tank
  • Auto or manual heating.

+-R800 for the controller and thermostat.

Hope this clears things up a little

 

Thys

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viper_za, great  feature description.

only the obvious one is missing: can start / stop geyser manually (but next timer cycle will resume timer) or switch off geyser without going to board or isolator.

After installing heatpump (using exising geyser for storage) Kwikhot  installer put timer on 1min/day to protect magnesium rod inside geyser from quick corrosion.

Manual start / stop is useful to easily resume geyser operation should heatpump enter an error mode (example: when filter needs to be clean) and daughter starts screaming before I had a chance to resolve error because she wants HOT WATER NOW !

2 hours ago, viper_za said:

The Geyserwise uses it's own thermostat replacing the existing one you have.

... if you have certain older models of geysers. For some newer models (example: my Kwikhot) replacing is not required since GeyserWise can use existing thermostat

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