Discuss clearline v210 in the Solar PV Forum area at ElectriciansForums.net

Status
Not open for further replies.

oldtimer

Regular EF Member
Messages
4,313
Location
Edinburgh
Hi guys
Looking for a bit advice here I have just moved into a flat that has a Clearline V210 solar system that is meant to heat up the water in the immersion but on a day like today the return from the panels is very hot ie hot enough so you cannot hold on to it suspect 65oC now the water going into the cylinder is hot coming out is cold or ambient thing is I dont appear to be getting a good heat exchange.

Now to give a bit of background on me I have worked with HVAC /BMS controls for the past 25 years only thing is I have never been exposed to this type of technology so my thinking is is this system meant to raise the water above ambient and if so what should it be ?

thanks for any help
 

Gavin A

Electrician's Arms
Solar Guru
Messages
4,238
Location
Leeds
bit more info needed please

what size cylinder is it?

is it a dual coil cylinder with the solar input to the lower coil, and a second coil for the gas / oil boiler?

or

Seperate solar cylinder with solar flow and return to a coil, but just an immersion heater for the back up heating?

Or standard gas / oil heated tank, but the solar input goes in via the immersion heater boss? (there are such retrofit systems)

or something else?

How many panels, and are they flat panels or evacuated tubes (if so how many tubes?)

any idea if the solar fluid is flowing correctly?

What's the pressure in the system when it's cold?

erm... that should do for now.


tbh, as long as it's been sized correctly originally, my money would be on a partial airlock restricting the flow, unless it's seriously old and the coils are all scaled up.

It does take quite a while for solar water heating set ups to heat the entire tank mind - they're designed to heat the whole tank over most of a day generally, rather than heating it all in an hour then switching off like a boiler would.
 
OP
O

oldtimer

Regular EF Member
Messages
4,313
Location
Edinburgh
bit more info needed please

what size cylinder is it?

210litres

is it a dual coil cylinder with the solar input to the lower coil, and a second coil for the gas / oil boiler? YES

or

Seperate solar cylinder with solar flow and return to a coil, but just an immersion heater for the back up heating?

Or standard gas / oil heated tank, but the solar input goes in via the immersion heater boss? (there are such retrofit systems)

or something else?

How many panels, and are they flat panels or evacuated tubes (if so how many tubes?) Dont know I ie cannot see them on the roof

any idea if the solar fluid is flowing correctly? Dont think so if it is its one hell of a temperature drop across the coil

What's the pressure in the system when it's cold? dont know but it was 2.2bar when I wrote the post its now 0.5 bar

erm... that should do for now.


tbh, as long as it's been sized correctly originally, my money would be on a partial airlock restricting the flow, unless it's seriously old and the coils are all scaled up.2 years old

It does take quite a while for solar water heating set ups to heat the entire tank mind - they're designed to heat the whole tank over most of a day generally, rather than heating it all in an hour then switching off like a boiler would.
thanks for your help also I wrote this post about 16:00 so yep it has had a whole day plus I whats the best way to bleed it
 
Last edited:

The Solar King

Electrician's Arms
Solar Guru
Messages
911
Location
Edinburgh
I fit Viridian Solar kit as it is just about the best on the market. I am close by. Pm me and I'm more than happy to come and have a look.
 
OP
O

oldtimer

Regular EF Member
Messages
4,313
Location
Edinburgh
A Canmore Dunedin house in Gilmerton by any chance?
No comment respect my privacy I can and probably will get the landlord out to look at it but I must admit I have covered a lot in my years but PV just seem to fly bye me also I am not a fiddiler as they say just curious so I wont be stripping thing down any time now.

Thanks again
 

The Solar King

Electrician's Arms
Solar Guru
Messages
911
Location
Edinburgh
Sorry oldtimer, didn't mean to intrude. Reason for mentioning it is I saw these go in and was less than impressed with the standard of workmanship on the internal plumbing. I always use mechanical joints (compression fittings), but pipes had been soldered. System specification says this can be OK to use solder but only if it is high temperature silver solder. Personally I would never risk it.

On a good day your tank can be full of hot water at 65deg C by 11.00am. The system then shuts down until any hot water is run off or the tank temperature falls. The temperature in the panel can then rise to more than 200deg C. (this is called stagnation). When water is drawn off and the system restarts to heat the cold from the mains that is now in the bottom of the tank, you can end up with a burst of super heated circulation fluid or vapour scooshing down from the panel, hence the expansion vessel. If you have joints with normal solder, it can be softened. Repeated doses of high temperature fluid can lead to leaks.

It sounds like you have a pressurised system as opposed to a drain back. A great number of Viridian systems have the drain back configuration because of its simplicity. With a pressurised system there is no way of bleeding it without a filling pump which is a bit of external kit that is attached to the solar circuit at the controller. Older designs of other make of system used to have a bleed valve at the panel. Viridian systems do not require that, but do need to be filled correctly in the first place.

System pressure when not running should be 1 Bar. Your 0.5 Bar suggests there may be an issue. Pressure when running will alter with fluid temperature. With the size of hot water cylinder you have I would expect you to have 4SqM of panel. There is a flow rate indicator on the left hand pipe in the bottom right hand corner of the controller. When running this should show a flow rate of 3.5Ltrs/Min. It is not unusual to get a high temperature drop between the inlet and outlet of the solar coil. If it is a half decent tank this should be a high efficiency finned job with a large surface area to maximise heat exchange within the tank.

The solar system should turn off when tank temperature reaches 60deg C. If you have an unvented cylinder there is also a high limit stat on an interlock to the solar controller at around 65deg C to prevent it getting any hotter. There should also be a thermostatic mixing valve on the tank outlet set to no more than 45Deg C or TMVs at every tap. This can make you wonder if the thing is working properly as hot tap outlet temperature is never more than this (this still feels pretty hot).

Don't know if all this helps, but feel free to ask anything else.
 

Gavin A

Electrician's Arms
Solar Guru
Messages
4,238
Location
Leeds
With a pressurised system there is no way of bleeding it without a filling pump which is a bit of external kit that is attached to the solar circuit at the controller. Older designs of other make of system used to have a bleed valve at the panel. Viridian systems do not require that, but do need to be filled correctly in the first place.
oh really?

I hope I never have to service one of them then... although I guess we do have the pump to pump the air through, I'm always a bit suspicious of that, and like to have a bleed valve at the top as well personally.
 

The Solar King

Electrician's Arms
Solar Guru
Messages
911
Location
Edinburgh
Understand your point but it has never been an issue. Before fitting Viridian systems we would always fit an Air Scoop (air seperator) in to the the solar circuit. This makes life very easy and there is no fooling around on roofs during commissioning or servicing. You can get them from Secon Solar. We have gone one better by fitting an Air Scoop to the outlet of the filling pump so fluid is de-airated before it enters the system. If we get called to a system we didn't install, the chances are we can leave the roof alone.

Incidentally, the Viridian system is specifically designed to have no roof side plumbing interevention. The panels are roof integrated with high temp flexys on the back. They are quick and a doddle to fit. There is no need to schedule roofers and plumbers on the same day giving greater flexibility in installation. This is one of many resons why Viridian is so popular for new build.
 
Last edited:

eamonn1983

EF Member
Messages
6
Am I right in saying that the supply to the pumping station needs to through the high limit stat on the tank so if the tank is too hot it cuts off the electrical supply to the pumping station? If this is the case what happens the water being heater in the panel if supply is interrupted ??
 

The Solar King

Electrician's Arms
Solar Guru
Messages
911
Location
Edinburgh
Yes it must be wired through the high limit stat. When the tank cools due to draw off or standing loss, electrical supply will be restored when the stat closes.


As described earlier in this thread, if the system is fully filled and pressurised, the fluid in the panel becomes very hot. The fluid and the system are designed to cope with this. This is what is called stagnation. It is also why there is an expansion vessel. As soon as the system starts up, fluid circulates and the heat is removed from the panel and placed in the tank.

In a drain back system, just the panel gets hot. The advantage of this kind of system is much slower degradation of the circulation fluid and general simplicity.
 
Status
Not open for further replies.

Permanent unswitched live colour?

  • Brown

    Votes: 64 66.0%
  • Black

    Votes: 33 34.0%

Electrician Talk

Top