Correct location of fuse(s) in parallel solar panel connection - Page 1
Forum section: electronics / general

author: abhishekkumar1902
author_rank: Regular Contributor
timestamp: May 30, 2018, 09:13:42 am
content: I have four 150 watt Solar panels which I am planning to connect in parallel to increase the current output. The spec of the panels are:Nominal Maximum Power (Pm)150Watts/12VOpen Circuit Voltage (Voc)22.50VShort Circuit Current (Isc)8.81AVoltage at Maximum Power (Vmp)17.96VCurrent at Maximum Power (Imp)8.36AMaximum System Voltage1000VLink:https://www.microtekdirect.com/product/microtek-pv-module-150w/I am just a bit confused where the location of fuse should be.Of all the panels, should I wire all the positives and negatives respectively first, and then just drop a single fuse (may be of 35A/40A) in between the charge controller and this parallel panel connection. Or should I first drop a fuse for each panel first before making a parallel connection and then connecting it to the charge controller?, thus requiring one fuse per panel.I also wanted to know what should be the amp rating of the fuse in each of the case mentioned above?

author: fourtytwo42
author_rank: Super Contributor
timestamp: May 30, 2018, 10:48:46 am
content: PV equipment generally (panels, cables & connectors) are not designed to support more than two panels in parallel.Perhaps you could use a series/parrallel connection ?

author: abhishekkumar1902
author_rank: Regular Contributor
timestamp: May 30, 2018, 11:26:11 am
content: "PV equipment generally (panels, cables & connectors) are not designed to support more than two panels in parallel.", What? Why? Are u kidding me?

author: fourtytwo42
author_rank: Super Contributor
timestamp: May 30, 2018, 12:22:20 pm
content: The cables and connector current rating is one reason, another is the reverse current rating of panels should they become shaded and several others. The vast bulk of panels are installed as series strings and that is the connection method assumed by the standard equipment, if you want to do something completely different it is up to you to make allowances.I would suggest for example the use of Schottky diodes in series with each panel to limit fault currents and the use of higher rated cables and connectors as apropriate.

author: abhishekkumar1902
author_rank: Regular Contributor
timestamp: May 30, 2018, 02:04:44 pm
content: What happens if I don't install a blocking diode for each panel provided:1.) Each panel had a bypass diode installed2.) All the panels are in sun with no shading

author: fourtytwo42
author_rank: Super Contributor
timestamp: May 30, 2018, 06:24:08 pm
content: What happens if you stick fingers in a power socketI probably should not have said that but power systems including PV are designed for safe operation.

author: abhishekkumar1902
author_rank: Regular Contributor
timestamp: May 31, 2018, 06:25:25 am
content: In a parallel connection, is there a way to get away with the blocking diode for each panel as they add a little voltage loss?

author: fourtytwo42
author_rank: Super Contributor
timestamp: May 31, 2018, 07:46:50 am
content: It's a bit pointless asking for advice if your responce is to ask why you should take it!