Classic 250 cp Case temperature to hot to touch

[The Ugly One]

So I have 2 classic 250 cp installed and some days, well slot of days the case is to hot to touch. So one of them has 5x 270 watt talesun tp660p-270 panels connected up to it. And the other has 10 panels connected as (5x in series) (5x in series) then they are combined together in parallel. So 1 classic has 5 and the other has 10. What would be causing them to be running so hot. They are connected to 2x 48v 510ah batteries.

Thanks for any/all input with this.

[ralph day]

I'm not as well versed on the Midnite technical issues but here's my working setup. 

1 Classic 250 for 2.1kw pv, I have it's aux 2 function as, i think, "daylight"...it activates when the Classic  wakes up.  It's relay running a 55cfm muffin fan blowing on it.  The Classic's fans never run, cool to the touch.

1 classic 250 on a Bergey XL1.  No external fans as there's not that much activity.  It's fans do run sometimes, even the turbo fan has been heard to run when there's been a big windstorm.

[ClassicCrazy]

So I have 2 classic 250 cp installed and some days, well slot of days the case is to hot to touch. So one of them has 5x 270 watt talesun tp660p-270 panels connected up to it. And the other has 10 panels connected as (5x in series) (5x in series) then they are combined together in parallel. So 1 classic has 5 and the other has 10. What would be causing them to be running so hot. They are connected to 2x 48v 510ah batteries.

Thanks for any/all input with this.

What are the temperatures that the MNGP is showing for the Classic ?

Larry

[Vic]

Hi T U O,

Just to add,   The ambient temperature around the Classics can be important to how effective the  Classic's fans are,   in extracting heat.

The Classic with 2700 W of PV,  is  shown to have 90% utilization,  in the string sizer,  output  Attached,  below.

Relatively high input voltage,   high  ambient temps,  large PV arrays  and high voltage  model Classics will all increase Classic operating temperatures (to varying degrees).

FWIW,   Vic

[The Ugly One]

Charger 250 cp 1: 5x Pv talesun panels
Day 3:
173.3 v
52.4 *c
858 watts

Day 12:
Hi vPV- 169.9
58.1*c
1083 watts power

Charger 250 cp 2: 10x PC talesun panels
Day 3:
174 v
72.5 *c
2007 watts

Day 12:
Hi vpv- 166
73.9*c
2123 watts power

I choose 2 random days from the log.

[The Ugly One]

So I shouldn't be that worried? I am cutting in an exhaust fan and will have it blowing air directly on them to help with the heat.

[Vic]

Hi T U O,

It seems that MidNite is not overly concerned about CC heating,  as evidenced by the evaluation from the String Sizer.

74-ish C is about 165 F.   And,   electronics generally do not like high heat situations.   But,  you should still expect a number of years of service from the CC with 2700 W of PV (at STC).   more or less.   Other factors could change this  --  like near by lightning.

You would probably need to replace fans in the Classics with the greatest heating more often.  And ultimately,  some other electronic part may well give up due to high heat,  compared to  Classics that have lead a more sheltered life.   But   MN does not appear to be worrying all night about this.

Just guesses,   FWIW   Good Luck,  Vic

[boB]

74 degrees C  for FET temperature is starting to get up there but it's OK.  Unless there is something going on where the temps are actually much higher than this, these are not all that abnormal high-ish FET temperatures.  You've got somewhere around almost another 15 degrees C of FET temperature before the Classic starts to reduce its output level in order to keep from getting hotter.

BTW, the maximum FET die temperature inside the parts are actually rated to 175 degrees C so they are pretty cool as far as FET temperatures go, although the actual internal FET temperatures will be hotter than the Classic FET temperature reading.

Do you know what the temperature is of the case ?   

Is there a high ambient temperature there now ?   It could be that high ambient is making things a bit toasty.

But if those internal temps are accurate, this should be nothing to worry about.

[daklein]

Ugly,  what is the ambient temperature in cabinet, if these are still inside a DC solar trailer cabinet?  If the Sunny Islands are on in there also, that could be adding heat.

[The Ugly One]

They are not taken from a dc solar trailer. The systems are from all new in box equipment. Having put a fan mounted directly on them keeps them cooled down.

[KyleM]

Do you have a picture of your set up?  Maybe it is something environmental.

The airflow of the Classic runs in from the bottom of the Classic, out the top through the Turbo fan. If you have the bottom screens of the Classic blocked it will have trouble getting air across the boards thus not cooling the Classic efficiently.
-KyleM

[The Ugly One]

I will take a picture when I go back there in a couple days. I only have an incomplete picture during install. And yes the vents in the bottom are not covered fully. Each charger sits about 1 1/2 inch above the others because I have the conduit of each running out the right hand side of them to the e-panel

[boB]

I forget...  Did you measure the temperature of the outside of the Classic ?   55 degrees C can feel very hot to the touch but not so bad for the electronics.

Doesn't hurt to check it out though.