Advertisement
If you have a new account but are having problems posting or verifying your account, please email us on hello@boards.ie for help. Thanks :)
Hello all! Please ensure that you are posting a new thread or question in the appropriate forum. The Feedback forum is overwhelmed with questions that are having to be moved elsewhere. If you need help to verify your account contact hello@boards.ie
Hi all! We have been experiencing an issue on site where threads have been missing the latest postings. The platform host Vanilla are working on this issue. A workaround that has been used by some is to navigate back from 1 to 10+ pages to re-sync the thread and this will then show the latest posts. Thanks, Mike.
Hi there,
There is an issue with role permissions that is being worked on at the moment.
If you are having trouble with access or permissions on regional forums please post here to get access: https://www.boards.ie/discussion/2058365403/you-do-not-have-permission-for-that#latest

T1 Value off the scale

  • 27-12-2009 2:40pm
    #1
    sundodger5
    Registered Users, Registered Users 2 Posts: 1,176 ✭✭✭


    hi all, somehow in the last couple of days something has happened to my solar setup.
    i now have a T1 value at -999 degrees.
    I am assuming that means no reading from the sensor. what could have caused this? also how to diagnose exactly what the problem is?
    thanks Mark....


Comments

  • #2
    quentingargan
    Registered Users, Registered Users 2 Posts: 1,627 ✭✭✭quentingargan


    sundodger5 wrote: »
    hi all, somehow in the last couple of days something has happened to my solar setup.
    i now have a T1 value at -999 degrees.
    I am assuming that means no reading from the sensor. what could have caused this? also how to diagnose exactly what the problem is?
    thanks Mark....

    Hi Mark, You are right that there is no reading from the sensor. I assume that T1 is the panel temperature? The most common cause is a loose connection and/or break in the join between the sensor in the panel and the controller. Generally the sensor comes with a 2m lead and this is joined in a junction box in the loft to an extension lead coming to the controller.

    That junction box is sometimes also a lightening protector which may also have failed. But usually at this time of the year I would ask if anyone has been chucking stuff into the loft and might have stretched the wire?

    You don't mention the brand of your controller, but on many of them the sensor itself is a PT1000 thermistor. This is a variable resistor which has a resistance of about 1,350 ohms at 0 degrees, falling to about 1K at 100 degrees (from memory). A PT100 probe goes from about 134 ohms to 100 ohms. If you have a multimeter, you could check the resistance on one of the other probes to see if it is that range. You could then work backwards from the controller along the lead in the attic. If the lead coming into the attic from the panel is out of the range then you have a problem on the roof.... Hope that isn't the case.

    Lets know how that goes.

    Q


  • #3
    [Deleted User]
    Posts: 31,118 ✭✭✭✭ [Deleted User]


    I had a similar issue with a temperature sensor a few months ago, it was water in a connecter that caused it to give crazy readings.

    The other thing to check is that the cable isn't chafed and touching an earthed piece of metal.


  • #4
    sundodger5
    Registered Users, Registered Users 2 Posts: 1,176 ✭✭✭sundodger5


    Thanks for the replies. went out to do a couple of checks and it has fixed itself.
    this to my mind is even more annoying.
    I am going to have a look at the connections etc anyway.
    The controller is an esr 21d seems fairly basic but i never got a manual.
    If things bad a gain i will let you know.


Advertisement