tristar mppt60

[billi]

Do you have  the  recent  temperatures from your area in France ?  Is it getting down to -10°   during the day ?

[eabadger]

lowest so far since november was today at 8am (still dark) it was -1, by the time the sun got round to the pv, it was 8*.
does get cold here, but so far this winter very good weather, due to get down to -3 on Monday.

so chance of voltage going above 150v is slim in my opinion, and even if it did, protection? maybe i just got a dud one, dont mind as long as it is replaced, and soon, as very sunny today.

Thank for other messages, I am an electronics engineer by trade, but have been off work due to an eyesight problem, used to repair down to SMD level, now have a job seeing where the digger bucket is, perfect eyesight in right eye, but all perception of depth lost due to bad left eye, if they come the old will cost route, I will get it back and repair it myself, but thought at £590 and only 4 months old I would return it, lets see, maybe I am worrying for no reason.
Make of the panels, not sure, oem, I have monitored voltage over the last few days, and today which is cold and sunny, no more than 21v.



steve

[billi]

Morningstar have a string sizing calculator on their Website  and  at -10  it looks borderline all right,  with 6 modules in series

At 0°  it says  configuration optimal

But do not know your Modul ..... so used a standard 80 Watt one

Perhaps  it would help to indicate that there where no  such low degrees

Just a thought

Billi

[eabadger]

my last reply was to that effect, stopped working at 11*, but had no reply to this email, maybe they will post me a new unit now? i used the string calculator before going for the 6 x3 strings.
i have all the logs since fitting in late August and see no volts above 126v. but some errors saying high array current volatge, but again volts below limit, well below, in the manaul it shows the current being clipped when the array volts go above 140v, going back to my orriginal post, i ahave never seen above 1090w from a 1440w array, so maybe it was clipping to low? and then commited suicide due to being incorect?

steve

[eabadger]

Ok, company have now said a new unit will be sent, the Tristar MPPT has a over voltage safety circuit, so in theory no matter how high the array voltage it will not pop.
I think mine had been dud from new, but how do you know, when it is all new? And no comparison?

I will report back and update status of Tristar mppt output, but I am going to drop strings down from 6 to 5 by adding some extra pv, we have some that are miss sited in the winter, with very little output, so could have full 1600w, 20x 80w units.

steve

[nick disjunkt]

Sorry to hijack the thread, but I recently brought a morningstar MPPT 45a and 8 x 100w (18v vmp) panels. I had intended to run 2 strings @48v nominal (well within the 150v max) but the morningstar string calculator is saying to use 4 strings of 2 panels with 800w, or just 2 panels per string with 2 strings. Why is this? I would rather use 4 per string to keep the voltage drop down and cable size to a minimum.

[billi]

Hi  

can it be  that you used the Tristar  45  instead  in the morningstar string calculator and NOT the Tristar MPPT 45


    Billi

[nick disjunkt]

Hi  can it be  that you used the Tristar  45  instead  in the morningstar string calculator and NOT the Tristar MPPT 45
    Billi

  I hope you're not accusing someone of my intellect of making a stupid mistake like that  

On an unrelated note, I have resolved the issue.

[billi]

Stupid   is only Morningstar ......  for not giving a  new advanced/different   product  another name, than one of their  older products 

[nick disjunkt]

Stupid   is only Morningstar ......  for not giving a  new advanced/different   product  another name, than one of their  older products 

very true. The supplier initially sent me the old PWM controller by mistake so it's not just me that gets them muddled up.