September 4, 20232 yr Hi All. Apologies if this has been asked before. I Tried searching for content but could not find it. Inv Spec: 4500w PV 120V Min DC 450V Max DC 18A Max Current. The last is the concern I have many installations but never have I pushed limits so close. would like your input, please. The subject inverter currently has 9 x 335w panels in a single string ( VOC 416 DC) The client requested 12 Panels ( VOC 555 single string too high so split string 277vDC) But the amps will now go up 17.7 A(Imp) Is this safe / recommended? Your Thoughts?
September 4, 20232 yr 20 minutes ago, Tokolosh said: Hi All. Apologies if this has been asked before. I Tried searching for content but could not find it. Inv Spec: 4500w PV 120V Min DC 450V Max DC 18A Max Current. The last is the concern I have many installations but never have I pushed limits so close. would like your input, please. The subject inverter currently has 9 x 335w panels in a single string ( VOC 416 DC) The client requested 12 Panels ( VOC 555 single string too high so split string 277vDC) But the amps will now go up 17.7 A(Imp) Is this safe / recommended? Your Thoughts? You should be fine your total wattage then 12 x 355 =4260watts you within the 4500w of your Mppt. Important part is that your Voc won't exceed Mppt max voltage input. I assume the 17.7A is the Imp of the panels. Edited September 4, 20232 yr by TaliaB
September 4, 20232 yr I was just wondering how you got to 17.7A if you are doing 6s2p with identical panels either 17.6A or 17.8A meaning 1 string either 8.8A or 8.9A. Edit ok 8.85A/ string. Edited September 4, 20232 yr by TaliaB
September 4, 20232 yr 1 hour ago, Tokolosh said: Hi All. Apologies if this has been asked before. I Tried searching for content but could not find it. Inv Spec: 4500w PV 120V Min DC 450V Max DC 18A Max Current. The last is the concern I have many installations but never have I pushed limits so close. would like your input, please. The subject inverter currently has 9 x 335w panels in a single string ( VOC 416 DC) The client requested 12 Panels ( VOC 555 single string too high so split string 277vDC) But the amps will now go up 17.7 A(Imp) Is this safe / recommended? Your Thoughts? Nothing wrong and no risk.
September 4, 20232 yr Author Thanks All for your input .. I've seen too many inverters POP due to miscalculations. and more so because of amps. but if you say this is the done thing.. Then so be it .. Thanks again.
September 4, 20232 yr 45 minutes ago, Tokolosh said: Thanks All for your input .. I've seen too many inverters POP due to miscalculations. and more so because of amps. but if you say this is the done thing.. Then so be it .. Thanks again. You will normally not see 17.7A as per the NMOT values on the spec sheet.2P. This is about 80% of the Imp in the STC specs
September 6, 20232 yr On 2023/09/04 at 11:43 PM, Scorp007 said: You will normally not see 17.7A Yes, but some limits are quite hard, like the Voc limit. I used to think that the 18 A limit was very hard, and pointed to a burned out solar charger as an example, but that's since been explained away as an issue of the case causing arcing from too-close high voltage studs or nuts. So I think that this will be OK.
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.