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Forum Index : Solar : Latronics PVE 2.5 kw
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BUGS Newbie Joined: 12/04/2007 Location: AustraliaPosts: 21 |
Hi, Can some one till how close the voltage has to be with different brands solar panels.I was wanting to put up enough string of panels.My system is a Conergy, 170 watt panels,4s X 2p = 8off. 35.9 vmpp, 44.5 voc Thanks Ivan BUGS |
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Bolty Regular Member Joined: 03/04/2008 Location: AustraliaPosts: 81 |
Hi Bugs If you look at the table from Latronics at the following link, you should be able to see similar panels. http://www.latronics.com/PVEComparison.htm You need to realize that the PVE2500 is a double voltage (and power) version of the PVE1200. Therefore your suggestion of 4 in series with 2 banks would provide an open circuit voltage of 178 volts, which would be ideal for the PVE 2500. I do know from a friend's experience with the PVE1200 that they do not like over-voltage. 110 volts is probably BANG! With the PVE2500 I would suggest 220 volts would do similar. Hope this helps! |
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BUGS Newbie Joined: 12/04/2007 Location: AustraliaPosts: 21 |
Thanks Bolty, My system is up but not turned on yet.Has to have the final inspection.I'm looking at importing 8 more panels,have found the right panel voltage now. Price (180w 44.8voc,36vmp)$2.98 watt delivered.Whating on an email for final prices. P.S.Maybe join forces an get 100'S BUGS |
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Bolty Regular Member Joined: 03/04/2008 Location: AustraliaPosts: 81 |
Hey Bugs! Glad to be of some help. I am impressed with the price at which you are getting panels. I know that they have come down recently, but that price of $2.98 is AWESOME! Did I understand you to suggest that you may do a bulk buy, and could be looking for others to be part of your order. If so, I would be very interested!! Please let me know if that is the case! |
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BjBlaster Regular Member Joined: 04/04/2008 Location: AustraliaPosts: 55 |
That is a great price! I would just like so say how awesome and reliable my latronics 1200 inverter is! I love AUSsie made and this is just KISS all over. You can't go wrong with this stuff. My pics are here for those who haven't seen it... Cheers Bj Check out my projects here in: Bj's Shed |
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GOFJ Newbie Joined: 22/12/2009 Location: AustraliaPosts: 27 |
I have the Latronics PVE2500 with 16 24V 180W panels, it normaly sits on 130V and up to 22A although I have seen 150V when it starts to go into current limiting (stinking hot days). I am so impressed with it (fit and forget) that I will be using one (with the Latronics controller and a dump load) with the F&P twin stator wind generator I am building. Once I have established the peak power there will be solar panels paralled to utilise the excess capacity. Jack |
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BUGS Newbie Joined: 12/04/2007 Location: AustraliaPosts: 21 |
Hey Jack, You have done what I'm going to do,only with 170 watt panels.The new PVE2500 has new ratings,now 3100watts max. Still haven't made my mind up yet about importing panels from China, like every one else.I was thinking of one pallet (48) first,to see how they go. Yes buy aussie first,if you can. BUGS |
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neil0mac Senior Member Joined: 26/12/2009 Location: AustraliaPosts: 210 |
Is that with or wirhout the '3500V via Toroidal Transformer' that they mention? What is the correlation, if any? |
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GOFJ Newbie Joined: 22/12/2009 Location: AustraliaPosts: 27 |
Yes, and because of that it weighs a ton when you are trying to bolt it up on the wall. The transformer provides electrical isolation from mains voltage with a breakdown voltage of 3,500 volts. It holds the voltage from the panels to 130V (the peak power point) and the current varies acording to the sun light available up to the point where it starts to limit current (thermal protection of the output transistors). I have 4 strings of 4 nominal 24V 180W panels in parallel Jack |
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GOFJ Newbie Joined: 22/12/2009 Location: AustraliaPosts: 27 |
With the hot weather we have been experiencing I have noticed a reduction in output from 15 kWh per day to 13.2 kWh. Sunday I sprung the inverter in complete shutdown with the out of range LED lit. It then started but only 15A and 150V DC. The ambient temp was 42 and inverter case 60 Deg C. The setup is pannels on the north facing roof of a east/west shed and the inverter is mounted off the internal west face (with a 75mm air gap and thermal insulation to the wall). I set up a crude evap cooler, a container of water with a teatowel in the water hanging over the side (Coolgardie safe style) and a 10W axial fan blowing across it to the inverter and its air intake. Within minutes the input current rose to 23A and 145V DC. The lesson to be learned is, if possible, locate the inverter in the house where it can enjoy the humans temperature range otherwise you could be limiting the total power output, alternativly set up some additional cooling for the stinker days. Jack |
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neil0mac Senior Member Joined: 26/12/2009 Location: AustraliaPosts: 210 |
"I set up a crude evap cooler, a container of water with a teatowel in the water hanging over the side (Coolgardie safe style) and a 10W axial fan blowing across it to the inverter and its air intake." Thanks Jack! What a shame - letting peak power production go to waste! Thanks for 'another tip' to use when putting my system together! I am presently playing with some ideas for a decent sized ground mounted 2 KW system. Plan to put a 'fish pond' where it will always be in the shade of the panels and a small pump (maybe a large 'car electric fuel pump' (or three!) - too small?) and fan to cool the 'closed in (shrouded) panels. Putting the inverter in the same location would make a whole lot of sense. The fun will come estimating the amount of BTUs to be removed and air/water volumes to do it along with finding a suitable fan. |
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GOFJ Newbie Joined: 22/12/2009 Location: AustraliaPosts: 27 |
neil0mac It would appear that the inverter is the most heat sensitive part of the system, as today at 1:00PM with a ambient of 43 deg C and hazy cloud I am still getting 22A. The pannels are mounted on a 2.4 meter high shed roof with an independent support structure, the low side is 200mm above the roof and the high side 1000 so there is plenty of air flow around them, the output does not seem to drop off significantly (now the inverter can use it). My cooler is using about 2-3 litres per day. Watch out for condensation as it could be a problem with corrosion or (even worse) flashover in the HV areas. Rather than putting water over the pannels or water jacketting them you could use a low powered fountain pump with a spray (very pretty ?) and then duct the resultant cooled air over the back of the pannels. The thermosyphon effect of the hot pannels should suck a respectable volume of cooled air through for free. There will be a significant buildup of salts in the water over time so watch out for potential corrosion points, another reason for a fountain pump rather than car pump. Run the pump with a timer only during daylight hours to advoid it pushing the RH up to dew point (and save a miniscule amount of energy at the same time). Jack |
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neil0mac Senior Member Joined: 26/12/2009 Location: AustraliaPosts: 210 |
Is the heat largely generated by the Inverter or ambient air temp? Shouldn't be a problem with a small(ish) evaporative Air Con? Plan to use of (several) timers and solenoids for switching/locking things. |
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neil0mac Senior Member Joined: 26/12/2009 Location: AustraliaPosts: 210 |
But a spray could carry unwanted droplets where you don't want them? So an evaporative type setup would be even better? Not if I use 'rainwater'? I plan to make good use of two (or more) timers. |
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GOFJ Newbie Joined: 22/12/2009 Location: AustraliaPosts: 27 |
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GOFJ Newbie Joined: 22/12/2009 Location: AustraliaPosts: 27 |
A crude (read easy) fix would be to duct a commercial evap. cooler over the back of the panels and the inverter, controlled by either a thermal switch or triggered when the inverter fan cuts in. Jack |
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neil0mac Senior Member Joined: 26/12/2009 Location: AustraliaPosts: 210 |
Much prefer the thermal switch. (It can be set to cut in earlier, plus I have another reason for using it (panel cooling) AND a 'commercial' evap. cooler (literally 'swung' off the back of the tracker frame). I actually want the pump to send water from the fish pond to the cooler. |
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neil0mac Senior Member Joined: 26/12/2009 Location: AustraliaPosts: 210 |
You need a fan to force the air through an evaporator pad because of air friction. By using a stilling (a reasonable volume) chamber and large droplet size from a fountain pump, not a mister (fine droplets) the liquid droplets will remain behind to be re-pumped while allowing the (slow moving) cooled air to go and do its job without wetting things Air friction would only be a problem IF the volume per minute was high and the evaporative panels were too small. OK. So, it wouldn't be an unmodded bit of gear. |
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GOFJ Newbie Joined: 22/12/2009 Location: AustraliaPosts: 27 |
If you go for large evap. panels you will also need a large (relative) pump to prevent dry spots allowing un-cooled air through. You will also need to exclude as much light from the water as it will encourage alge growth which will choke up the evap. panels and everything else, although it can be controlled with chemicals (which they do in cooling towers). Jack |
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