help needed guys please regarding inverter choice

[wstevew]

I have 2 strings of 8 suntech STP240S in a 4000TL all is fine.

However 6 suntech panels will be about 182v (compared to my system).

Although the start up volts can be set for each tracker down to 125v I read somewhere the tracker range is 175 to 550v. Which may be a problem.

NEW SB3600TL?

 

[SpitfireW'sale]

Have I misunderstood you or got confused?

Just the highlighted bits; I though that a Power One Inverter was capable of handling two unequal inputs in a more-or-less normal way, as long as all panels in each of the two strings were in the same lighing conditions (therefore bypass diodes not involved). ?
e.g. I thought that a Power One's dual inputs had no problems with (say) a string of four which get sun in the morning and a second string of six which get sun in the afternoon.

Sorry if I've misunderstood or misinterpreted your words.

This has been covered by others since your post, but just to clarify: The Power One can handle two unequal inputs as you correctly say. The two inputs (strings) do not need to be in the same lighting conditions, as there are two MPP trackers which handle each string independently. In effect, a dual tracker inverter is similar to having two separate inverters. A problem can occur when you attach two strings, each with different light conditions, to an inverter which only has 1 X MPP tracker, as in your case. This will result in losses (and possibly significant losses depending on the difference in light conditions of each string)

 

[Shirehorse99]

hi guys after a few weeks of negotiation my installer agreed to a power-one 3.6 and had agreed to install in a couple of weeks at no cost to me . Today however after a phone call today he can only get a PVI-3.6-OUTD outdoor version.
When using the online string tool the inverter efficiency is now only 83.1% compared to 90.6% of the PVI-3.6.
is this OK ?

thanks again for your help - i'll be bloody glad to get this sorted!!

 

[babba]

try 3.0 OUTD

 

[Shirehorse99]

i looked at the 3.0 OUTD - but is 99% utilisation a bit too much - inverter working at full capacity?

 

[babba]

I would use 3.0 but its your install.

 

[Shirehorse99]

I would use 3.0 but its your install.

Will a 3.6 be no good then as he has ordered it now.
And why is the outdoor one different in efficiency to the indoor one

 

[babba]

If he has ordered it he can change the order. Look at the data sheet for 3.6 and 3.6 OUTD they are the same minus a fan.
People tend to go for the OUTD, never heard of anyone buying a 3.6...but I on a forum so we may get someone.

 

[Earthstore]

I think you may have answered the questions asked.
If the 3.6 OUTD does not have a fan, then it stands the potential to run hotter, which is why there must be a difference in output.
Now the 3.6 with a fan, is designed for indoor use to cool the inverter therefore giving better performance and probably longevity also.
This is not my field of expertise, however I think that makes sense.

 

[Shirehorse99]

If he has ordered it he can change the order. Look at the data sheet for 3.6 and 3.6 OUTD they are the same minus a fan.
People tend to go for the OUTD, never heard of anyone buying a 3.6...but I on a forum so we may get someone.

Although the 3.0 is optimum for the system - will there losses with the 3.6 given that they start at 120v

 

[babba]

They can all kick in at 120v but normal setting is 200v, as for losses I have heard so..what you gain at the bottom you loose at the top (never done tests). Im sure you could fit a 3.6 and it would work but not as well as 3.0

 

[babba]

I think you may have answered the questions asked.
If the 3.6 OUTD does not have a fan, then it stands the potential to run hotter, which is why there must be a difference in output.
Now the 3.6 with a fan, is designed for indoor use to cool the inverter therefore giving better performance and probably longevity also.
This is not my field of expertise, however I think that makes sense.

Only problem is they all go in the loft and lofts and fans..??...Plus if you have a south facing roof full of panels the loft will be a lot cooler as the panels are taking the heat not the roof tiles.

 

[SolarCity]

Okay, I'm getting a bit confused here to say the least.

He was going to get you a 3.6 but now he is getting you a 3.6 OUTD? A 3.6 is a 3.6 OUTD. There is no such thing as an indoor only model. There is a PVI 3600 which is an indoor model and presumably the model you are talking about?

If this is the case then I wouldn't worry. The 3.6 OUTD is more efficient anyway - it's a better model.

3.6 OUTD may be oversized but I don't think that this will result in loss of yield.

 

[Shirehorse99]

Solar thats what I like to hear , but if you use the string tool on p1's website they do give differing results

 

[babba]

Okay, I'm getting a bit confused here to say the least.

He was going to get you a 3.6 but now he is getting you a 3.6 OUTD? A 3.6 is a 3.6 OUTD. There is no such thing as an indoor only model. There is a PVI 3600 which is an indoor model and presumably the model you are talking about?

If this is the case then I wouldn't worry. The 3.6 OUTD is more efficient anyway - it's a better model.

3.6 OUTD may be oversized but I don't think that this will result in loss of yield.

just to add more confusion..the 3.6 indoor..I hope this link works..

PVI-2000, PVI-3600 | Power-One