Navitron Renewable Energy and Sustainability Forum

SOLAR PHOTOVOLTAIC => Solar Photovoltaic Systems => Topic started by: mccltd on April 01, 2020, 02:09:16 PM



Title: Solarimmersion died what should I replace it with
Post by: mccltd on April 01, 2020, 02:09:16 PM
Ok, it lasted 6 years but seems its finally given up on outputting.
what choices do I have to replace it with nowadays around the £250 mark, I see solar immersion do a mark IV for £229 but is there anything else I should look at?
I only have a 2kw solar system but it heated my hot water all through the summer ok.


Title: Re: Solarimmersion died what should I preface it with
Post by: ecogeorge on April 01, 2020, 02:32:32 PM
Got to be the Solic -google is your friend.
UK made , ONLY device that diverts 100% surplus.
Fitted 2 now -no issues.
No connection
George.
www.earthwiseproducts.co.uk


Title: Re: Solarimmersion died what should I preface it with
Post by: Fintray on April 01, 2020, 03:27:09 PM
If you're handy with a soldering iron you could buy a Mk2 PV router for half the price of your budget.


Title: Re: Solarimmersion died what should I replace it with
Post by: mccltd on April 02, 2020, 06:53:14 AM
Thanks I was looking for a dual output as in the summer once it had heated my water I was using the secondary output to run a fan.
I had seen another make that did that but can't remember what it was.


Title: Re: Solarimmersion died what should I replace it with
Post by: ecogeorge on April 02, 2020, 08:20:02 AM
How can you run a fan off a diversion controller ? surely they require a resistive load?
George


Title: Re: Solarimmersion died what should I replace it with
Post by: oliver90owner on April 02, 2020, 08:34:01 AM
Iíve seen items that turn on a device once the generated power exceeds a certain value (settable).  I expect that the load can then be of any value - even in excess of generation.  They must use grid power, I would suggest, or the load may be switched multiple times if the generation level varies around the device setting.

I think the Solic had this sort of option on early models, but soon dropped the option and made the unit a bit simpler (there were several dip switches to be set for power selection?) as Iím sure only a very small minority would have been silly enough to use it that way.


Title: Re: Solarimmersion died what should I replace it with
Post by: ecogeorge on April 02, 2020, 08:57:18 AM
I have successfully utilised 2 heaters by using a NO/NC relay/contactor.
Wire primary heater through NC contacts and secondary through NO.
Wire thermostat (needs NO connection ) to coil (a1 -a2) -when primary is satisfied thermostat closing connection on coil and contactor switches. Other heater then in circuit.
Primary heater will always take priority , coil will only consume power when heating secondary heater. 
As soon as primary heater drops below thermostat set temp it will switch back.

NO = normally open
NC= normally closed.
Its a cheap mod.
George


Title: Re: Solarimmersion died what should I replace it with
Post by: dc on April 02, 2020, 10:16:28 AM
The Solic looks good but is there any way to set it up to run with a Powervault as the priority?


Title: Re: Solarimmersion died what should I replace it with
Post by: greentangerine on April 02, 2020, 12:46:30 PM
It doesn't look like it supports a configurable export threshold; that's what I use to give my battery system charging priority over my Immersun.


Title: Re: Solarimmersion died what should I replace it with
Post by: mccltd on April 02, 2020, 01:09:38 PM
Hi George,
The secondary output on my solarimmersion was a relay contact no/nc and I could setup in the menu when it came on depending on what I was currently putting back into grid.
Could be wired/programmed for a few different things.
Found the other one I had read about but its more expensive than the IV version of the solarimmersion.
It was the Apollo Gem.
I presume your idea is like the image i have attached using a mains 5 pin relay?




Title: Re: Solarimmersion died what should I replace it with
Post by: Stig on April 02, 2020, 01:21:04 PM
That circuit would be a bad idea  sh*tfan: as you're driving an inductive load (the fan) from the inverter output.  If your relay had two independent sets of contacts you could use one (NO) as you've shown for the immersion (simple resistive load) and the other (NC) to switch the fan but directly from the mains rather than the inverter output.


Title: Re: Solarimmersion died what should I replace it with
Post by: pj on April 02, 2020, 04:27:40 PM
That circuit would be a bad idea  sh*tfan: as you're driving an inductive load (the fan) from the inverter output.  If your relay had two independent sets of contacts you could use one (NO) as you've shown for the immersion (simple resistive load) and the other (NC) to switch the fan but directly from the mains rather than the inverter output.
Stig, can I ask what is wrong with an inductive load? This is an output from a diverter (not inverter), which may be a solid state SSR or a mechanical relay. SSRs are regularly used to drive inductive loads - Solar thermal with variable pump speeds being a prime example on this forum. If it's a mechanical relay output, then it's no different to any other relay output.
What is the problem?


Title: Re: Solarimmersion died what should I replace it with
Post by: Stig on April 03, 2020, 08:15:05 AM
Sorry, misread your diagram as 'inverter' rather than 'diverter'.
No problem at all, as you were.  ;)


Title: Re: Solarimmersion died what should I replace it with
Post by: Tinbum on April 03, 2020, 10:57:42 AM
That circuit would be a bad idea  sh*tfan: as you're driving an inductive load (the fan) from the inverter output.  If your relay had two independent sets of contacts you could use one (NO) as you've shown for the immersion (simple resistive load) and the other (NC) to switch the fan but directly from the mains rather than the inverter output.
Stig, can I ask what is wrong with an inductive load? This is an output from a diverter (not inverter), which may be a solid state SSR or a mechanical relay. SSRs are regularly used to drive inductive loads - Solar thermal with variable pump speeds being a prime example on this forum. If it's a mechanical relay output, then it's no different to any other relay output.
What is the problem?

It depends on the diverter and its output. If it has an on or off output then that's OK to power an inductive load but if its like most diverters where the output varies then no you can't. Even diverters with a relay often / mostly just route the variable power through that relay. Yes an SSR can drive an inductive load but it won't be switching on and off many times a second, as solar diverters do, to vary the power output.


Title: Re: Solarimmersion died what should I replace it with
Post by: pj on April 03, 2020, 01:59:40 PM
...Yes an SSR can drive an inductive load but it won't be switching on and off many times a second, as solar diverters do, to vary the power output.
An SSR can do precisely that - switch many times a second, whereas a mechanical relay can not.
My home grown diverter has an SSR output, and switches at 50Hz - I switch on or off every mains cycle, depending on the import/export of the previous cycle.
Commercial diverters typically use either zero crossing PWM or variable phase switching, through an SSR or Triac or some other electronic device.
I'm not sure I understand what you are getting at?


Title: Re: Solarimmersion died what should I replace it with
Post by: Tinbum on April 03, 2020, 04:22:33 PM
You can't switch an inductive load on and off many times a second. You will blow it or something else in the circuit up.

Have a read of the instructions for an SSR.


Title: Re: Solarimmersion died what should I replace it with
Post by: pj on April 03, 2020, 05:14:44 PM
You can't switch an inductive load on and off many times a second. You will blow it or something else in the circuit up.

Have a read of the instructions for an SSR.

From the Fotek SSR25DA spec sheet:-
"specially suited to control resistive, capacitive and non-saturated inductive loads"

From a Crydom Whitepaper:-
"Solid State Relays (SSRs) and Solid State Contactors (SSCs) are ideally suited for
controlling dynamic loads such as motors"
http://www.crydom.com/en/tech/white-papers/ac_mc_whitepaper.pdf (http://www.crydom.com/en/tech/white-papers/ac_mc_whitepaper.pdf)

I have a Resol Controller for my Solar Thermal, and it can vary the speed of the pump - I can set it in 10% increments from 30% to 100%. It uses a Solid State output, not a mechanical relay. Can you advise how this is achieved?


Title: Re: Solarimmersion died what should I replace it with
Post by: pj on April 04, 2020, 12:46:36 PM
You're right Tinbum, high speed PWM on certain classes of electric motor will cause smoke etc. Based on what I have read, it depends on the type of motor, and power rating etc.
Seems that these motors are ok when running, and ok when stopped (duh), but inbetween can be quite lossy. PWM can keep them in this inbetween state, and the losses can lead to overheating and failure.


Title: Re: Solarimmersion died what should I replace it with
Post by: Gareth J on April 09, 2020, 09:50:47 AM
Because your panel setup is only 2kw, you will never out generate the capacity of whatever solar diverter you use (they're all 3kw+ as far as I'm aware)

With this in mind, you can simply add more resistive loads to the circuit. Nothing will go bang, the diverter doesn't care if it's heating a 3kw immersion coil or a 10kw load. Bad things only start to happen if you potentially overload the diverter and that'll only happen if you exceed 3kW diverted power.

You can then switch in/out additional loads either manually, with relays, or smartly.

Have been running a solic200 feeding an old storage heater circuit with 3heaters on it. It can never divert more than 2.5kw (due to generation limit) so I switch them on/off manually or just leave them all on sometimes.

Note; an overnight boost timer will need to be separate and pick only the one load.


Title: Re: Solarimmersion died what should I replace it with
Post by: Tinbum on April 09, 2020, 10:42:08 AM
You can't switch an inductive load on and off many times a second. You will blow it or something else in the circuit up.

Have a read of the instructions for an SSR.

From the Fotek SSR25DA spec sheet:-
"specially suited to control resistive, capacitive and non-saturated inductive loads"

From a Crydom Whitepaper:-
"Solid State Relays (SSRs) and Solid State Contactors (SSCs) are ideally suited for
controlling dynamic loads such as motors"
http://www.crydom.com/en/tech/white-papers/ac_mc_whitepaper.pdf (http://www.crydom.com/en/tech/white-papers/ac_mc_whitepaper.pdf)

I have a Resol Controller for my Solar Thermal, and it can vary the speed of the pump - I can set it in 10% increments from 30% to 100%. It uses a Solid State output, not a mechanical relay. Can you advise how this is achieved?


Thinking about it my solar thermal varies the pump speeds and there are inverters for motor speed so yes it is possible but in this this case we are talking solar power 'diverters' and these are not designed for inductive loads. Perhaps it is something to do with a minimum speed for a pump / motor and something like an immerson etc does not have this programmed in.


Title: Re: Solarimmersion died what should I replace it with
Post by: echase on April 20, 2020, 12:06:04 PM
The Intelligent Immersion I2 or I2W has 2 outputs and a variable threshold down to zero.

Most of these diverters don't have fuse to protect the output SSR/triac/transistor so, if there is some external wiring fault, it blows the device and the warranty will not cover it. Basically it's then scrap. But the I2 has a fast fuse.

I retired from the company but I did design the I2.

We never recommended motor loads.  Motors with brushes might manage it but definitely not induction motors.