January 2, 20242 yr Hi, i need some opinions on a pv array. I am using a 48v system and i have six 270W panels that produce an average of 30volts & 7amps on avarage per panel. Now the question i have is what is the best way to connect them? Do i connect them 2, 2, 2 in series to make 60volts and 21amps Or should I connect 3, 3 to make 90volts and 14amps? Obviously this is not a constant output, but i guess the people who would answer me already know that. Thanx in advance.
January 2, 20242 yr 48 minutes ago, SetoKaiba said: Hi, i need some opinions on a pv array. I am using a 48v system and i have six 270W panels that produce an average of 30volts & 7amps on avarage per panel. Now the question i have is what is the best way to connect them? Do i connect them 2, 2, 2 in series to make 60volts and 21amps Or should I connect 3, 3 to make 90volts and 14amps? Obviously this is not a constant output, but i guess the people who would answer me already know that. Thanx in advance. It will depend on the type of inverter you are using or planning to use. You have 6 x 270w panels. By using a JA 270w panel as example the VOC-38v VMP-31.13v and Imp- 8.67A. Now connecting 6 panels in series 6S1P your Vmp will be 187v @ 8.67A.This method normally used on Mppt charge controllers. If you connect 6 panels in parallel 3S2P you will have 93v @ 17.34A or 2S3P you will have 62v @ 26A. Normally used on Pwm charge controllers. Edited January 2, 20242 yr by TaliaB
January 2, 20242 yr 46 minutes ago, SetoKaiba said: Hi, i need some opinions on a pv array. I am using a 48v system and i have six 270W panels that produce an average of 30volts & 7amps on avarage per panel. Now the question i have is what is the best way to connect them? Do i connect them 2, 2, 2 in series to make 60volts and 21amps Or should I connect 3, 3 to make 90volts and 14amps? Obviously this is not a constant output, but i guess the people who would answer me already know that. Thanx in advance. You have to give more info on the inverter's MPPT PV input requirements, or better, give the make and model of the inverter. Also, give the full specs, or make and model, of the 270W panel. You can't work on averages, you have to plan for worst-case or peak scenarios or some day something may blow.
January 2, 20242 yr 39 minutes ago, GreenFields said: You have to give more info on the inverter's MPPT PV input requirements, or better, give the make and model of the inverter. Also, give the full specs, or make and model, of the 270W panel. You can't work on averages, you have to plan for worst-case or peak scenarios or some day something may blow. ...or when you have sun-up, Mppt may not power up because the voltage is too low as well, which is, I guess better than having "something blow up".😁 Edited January 2, 20242 yr by Moffat
January 3, 20242 yr Author Here is a pic of the inverter label. The panels i will check when i get home tonight.
January 3, 20242 yr 33 minutes ago, SetoKaiba said: Here is a pic of the inverter label. The panels i will check when i get home tonight. Your panel connection configuration will be 3S2P. First calculate the Voc of 3S2P of your panel specs. I am using JA 270W for this exercise you need to substitute these values with your panel specs, label in the back of your panel. Voc- 37v x 3panels in series = 111v + 7.5%(0°C@STC)= 119.32v well below your inverter Voc of 145v. This model according to model name uses a MPPT Solar charge Controller 3000W 60Amp so above configuration would be the most efficient 3S2P.
January 3, 20242 yr Author Wow! Fast and on point. Thank you for that answer. Now i know for sure that the 3S2P connection is best. Someone told me to use inline fuses between the panels in series. Is that really necessary? I have a (4 in 1 out) combiner box with fuses and surge protector
January 3, 20242 yr 5 hours ago, SetoKaiba said: Wow! Fast and on point. Thank you for that answer. Now i know for sure that the 3S2P connection is best. Someone told me to use inline fuses between the panels in series. Is that really necessary? I have a (4 in 1 out) combiner box with fuses and surge protector If the short curcuit current(Isc) of the entire array is greater than the series fuse rating listed on the panel spec sticker then MC4 fuses must be used between each panel rated at the fuse on the spec sticker, otherwise if the short curcuit current(Isc)of the entire array is less that the maximum fuse rating on the panel spec sticker then fuses between panels are not needed but a solar disconnect is always needed. Care must be taken with panels in parallel and i will always install Mc4 fuses in any array that has a parallel configuration even if you have fuses in the combiner box.
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