Solar tubes temperature issue

peter65

Hi folks

I have a SMT100 solar control panel connected to HP200 vacuum tubes. I had the tubes replaced, 12 months ago, as the old ones got damaged during the bad frost, hence the older control panel. Anyway, I'm now starting to get some strange temp readings. For example, This morning at 8am it displayed -16C. During the day it'll rise to well above the daily temp and this causes the pump to kick in which then sends cooler water into my tanks!

I was told that the control panel may be faulty. The panel is being sent the wrong info from the temp probe in the collector and I don't want to have to replace the control panel unnecessarily. Again, I was given a price of several hundred pounds.

My thinking is the probe got damaged during the hard frost it wasnt replaced with the new tubes.
Sorry for the essay!!!

Any ideas/help

freddyuk

How did the tubes get damaged by frost? They do not contain water so I wonder what that problem was? And all 12 !!?? Sounds odd.
The controller I think has been discontinued but try resetting back to factory setting? That should give you basic operating programme that will pump only at correct temperature. The manual should explain this?
The probe should not get damaged by frost either.
Either the controller has the wrong programme operating and needs resetting or it has malfunctioned and needs replacing. It will not cost 100's to replace with a decent controller either. PM me if you need some help with this.

shane0007

peter65 wrote: »

Hi folks

I have a SMT100 solar control panel connected to HP200 vacuum tubes. I had the tubes replaced, 12 months ago, as the old ones got damaged during the bad frost, hence the older control panel. Anyway, I'm now starting to get some strange temp readings. For example, This morning at 8am it displayed -16C. During the day it'll rise to well above the daily temp and this causes the pump to kick in which then sends cooler water into my tanks!

I was told that the control panel may be faulty. The panel is being sent the wrong info from the temp probe in the collector and I don't want to have to replace the control panel unnecessarily. Again, I was given a price of several hundred pounds.

My thinking is the probe got damaged during the hard frost it wasnt replaced with the new tubes.
Sorry for the essay!!!

Any ideas/help

It sounds like the probe is faulty. If you look at the data sheet on the manual, it will list the correct resistance reading at a given temperature. With a multimeter, check the resistance of your probe (this can be done by disconnecting the wires within the controller rather than at the roof (but they must be disconnected) and compare with the required resistance. If the resistance is correct, then it could be the pcb board within the controller.

peter65

I have the plumber coming out today and i'll put that idea to him. Even without looking at the panel he wants to replace it so I'll see what he says and get back to you. thanks

peter65

Update - Changed the probe yesterday but found that the problem hasn't gone away. For some reason it drops into the minus figures once the sun goes down but during the day it seems to give the correct reading? Does anyone know how much a new control panel for HP200 tubes would be?

Thanks

sas

peter65 wrote: »

Update - Changed the probe yesterday but found that the problem hasn't gone away. For some reason it drops into the minus figures once the sun goes down but during the day it seems to give the correct reading? Does anyone know how much a new control panel for HP200 tubes would be?

Thanks

The best of the Kingspan ones (SC300) can be bought online for €280 inc vat. I'll pm the site I found it on. The cheapest one (SC100) is about €143 on the same site.

SC300 has the data logging facility.

shane0007

sas wrote: »

peter65 wrote: »

Update - Changed the probe yesterday but found that the problem hasn't gone away. For some reason it drops into the minus figures once the sun goes down but during the day it seems to give the correct reading? Does anyone know how much a new control panel for HP200 tubes would be?

Thanks

The best of the Kingspan ones (SC300) can be bought online for €280 inc vat. I'll pm the site I found it on. The cheapest one (SC100) is about €143 on the same site.

SC300 has the data logging facility.

The SC300 is over-kill unless you need it, i.e. you need additional relays, a built-in time clock or run more sophisticated systems. The SC100 is an excellent choice for most installations and very easy to use.

sas

shane0007 wrote: »

The SC300 is over-kill unless you need it, i.e. you need additional relays, a built-in time clock or run more sophisticated systems. The SC100 is an excellent choice for most installations and very easy to use.

The data logging facility is the reason I'd like the 300. I don't believe the 200 has it.

I'd personally like to be able to monitor the performance of my system using proper recorded data.

peter65

Cheers for the advice I rang kingspan and the control model they recommend is the sc400. Checked around and its priced at £90+vat. Was thinking of going for it seeing its the same price as the older models? Sas thanks for the pm

shane0007

peter65 wrote: »

Cheers for the advice I rang kingspan and the control model they recommend is the sc400. Checked around and its priced at £90+vat. Was thinking of going for it seeing its the same price as the older models? Sas thanks for the pm

Yes they are replacing the SC100 with the SC400 as their standard kit component. I personally prefer the SC100 over the SC400 for one reason only, and that is the initial set up. The 400 is never ending, whereas the 100 is very straight forward. Both are equal in their perameters.

peter65

Thanks for the tip Shane. I'm trying to make it fit into an older system set up. My tank doesn't have a temp probe point at the top of the buffer tank so will have to use the probe on the return flow pipe. So less complicated is good!!! I was advised to drill new probe holes as the SMT probes are a different size from the SC models. Ineed to buy an extention cable for the collector probe as it only comes with 5m cable. Anyone any experience of this?

shane0007

peter65 wrote: »

Thanks for the tip Shane. I'm trying to make it fit into an older system set up. My tank doesn't have a temp probe point at the top of the buffer tank so will have to use the probe on the return flow pipe. So less complicated is good!!! I was advised to drill new probe holes as the SMT probes are a different size from the SC models. Ineed to buy an extention cable for the collector probe as it only comes with 5m cable. Anyone any experience of this?

Why are you using the sensor at the top of the buffer?
Also if it is a buffer it is very easy to retrofit a tank sensor pocket.
Any two core cable will suffice (speaker wire is standard). Use a small Obo box to make the connections.

peter65

Kingspan tech explained that the third probe should go to the top of the tank if possible but failing that it can go on the return pipe where the smt one currently is.

shane0007

peter65 wrote: »

Kingspan tech explained that the third probe should go to the top of the tank if possible but failing that it can go on the return pipe where the smt one currently is.

Ah, ok. I thought it was one of the other sensors was at fault as it seems by your description that it affected the controller functionality. T3 only has a display information only function and plays no part in the function of the system itself.

peter65

It was the collector probe that I thought was faulty but it's the controller itself that's faulty.

championc

I got an SC300 with my system purely for the data logging. Worth every cent I feel. I can tell everything that's happening on the system and even compare one month or year against another.

I have a probe for the top of the buffer purely to know how hot water is being heated to. It's no good having the bottom probe only because if you have a shower or whatever, the bottom temp will naturally fall to the temp of the incoming re-filling water.

Yes, the SC300 is overkill but I decided to also use the 3 remaining temp sensor links for other PT1000 sensors which I simply connected to the controller and ran to places on the house. So I am now reading and storing the temperature for the hall / landing and sitting room.

In case some don't know, the Kingspan Controllers are re-badged Steca controllers and the Steca software for displaying saved data is on their website. The SC300 is the Steca TR0603mc

Dozz

Hi, sorry to repost on an old issue. I'm having a similar problem as discussed at the start of the thread. Kingspan have said that either the probe needs to be replaced or the controller (100 series). I can find a replacement 100 controller and the new Kingspan one is between €3-400 euro. Can anyone recommend a cheaper basic controller that will do the same job?