Ken Woodward
New Member
Hi there, my apologies if this is already answered somewhere. I searched but could not find it.
I have a truck camper with two 100W solar panels on it. One came with the camper when it was new (it's a Northern Lite) and we had the second one (apparently identical to the first one) installed by a Northern Lite dealer. They are wired in parallel and go through the stock 30A PWM charge controller (Enerwatt EWC-30). I would like to add two more 100W panels. The original panels are 19.1V/5.23A and the two new ones are 18.0V/5.56A. I used some online calculators to compare series to parallel and it looks like parallel will only result is a slight loss (~2.5%).
I would like to connect all four panels together using two 4-to-1 harnesses and MC4 connectors to connect to the original wires that go down through the camper's fridge vent. Unfortunately, the guy who installed the second panel did not use Y harnesses with MC4 connectors to connect the panels together. He just cut the wires coming from the original panel and used butt-splice connectors and goop to make his own makeshift Y harnesses. And, he cut very close to the junction box on the original panel - so close that it will be difficult to cut those wires and add MC4 connectors. I can't undo the brackets to lift the panel for access unless I scrape away a bunch of Dicor and remove the mounting screws, and I'm not keen to do that.
So, here is my question (finally...): Is it OK to connect the two new panels in parallel using Y harnesses, and then use two more Y harnesses to connect the resulting two wires to the two wires that go through the fridge vent to the charge controller, like this:
I would use all MC4 connectors to do it. The result would be all the positive wires are connected to each other and all the negative wires are connected to each other, as desired. It wouldn't be as clean as 2x(4:1), but it should work, shouldn't it? Is there any reason why I should not do it?
Thanks!
I have a truck camper with two 100W solar panels on it. One came with the camper when it was new (it's a Northern Lite) and we had the second one (apparently identical to the first one) installed by a Northern Lite dealer. They are wired in parallel and go through the stock 30A PWM charge controller (Enerwatt EWC-30). I would like to add two more 100W panels. The original panels are 19.1V/5.23A and the two new ones are 18.0V/5.56A. I used some online calculators to compare series to parallel and it looks like parallel will only result is a slight loss (~2.5%).
I would like to connect all four panels together using two 4-to-1 harnesses and MC4 connectors to connect to the original wires that go down through the camper's fridge vent. Unfortunately, the guy who installed the second panel did not use Y harnesses with MC4 connectors to connect the panels together. He just cut the wires coming from the original panel and used butt-splice connectors and goop to make his own makeshift Y harnesses. And, he cut very close to the junction box on the original panel - so close that it will be difficult to cut those wires and add MC4 connectors. I can't undo the brackets to lift the panel for access unless I scrape away a bunch of Dicor and remove the mounting screws, and I'm not keen to do that.
So, here is my question (finally...): Is it OK to connect the two new panels in parallel using Y harnesses, and then use two more Y harnesses to connect the resulting two wires to the two wires that go through the fridge vent to the charge controller, like this:
I would use all MC4 connectors to do it. The result would be all the positive wires are connected to each other and all the negative wires are connected to each other, as desired. It wouldn't be as clean as 2x(4:1), but it should work, shouldn't it? Is there any reason why I should not do it?
Thanks!
