Safely Testing Large Solar

[Pelagic]

I am ready to test-install my 4 large 327 Watt Sunpower Solar panels on the Bimini rack.
This is for final adjustment prior to painting the racks and detailing the Bimini material.

Each Panel’s Rated Voltage=54.7 V; Rated Current= 5.98 A; Voc 64.9 V.

I also wanted to individualy test each panels output, in case there is a bad panel that would still be covered under warranty…
Each panels junction box comes with 1m of output cable MC4 Connectors

My working Plan is to mount 2 panels on each rack in shade…. Tape output cables secure…. Then physically mount on Bimini and confirm fit and output of each panel

My Solar newbie questions:
1… Any dangers or concern with that plan?
2… Using my AC/DC Clamp meter what is the best way of measuring each panels output?

[Pelagic]

Some Photos of the instalation design

[sailorboy1]

Would seem to me that all you need to do to check the panels is to check the open circuit voltage as I don't understand how in your plan you are going to check amperage.

[svlamorocha]

Originally Posted by Pelagic

I am ready to test-install my 4 large 327 Watt Sunpower Solar panels on the Bimini rack.
This is for final adjustment prior to painting the racks and detailing the Bimini material.

Each Panel’s Rated Voltage=54.7 V; Rated Current= 5.98 A; Voc 64.9 V.

I also wanted to individualy test each panels output, in case there is a bad panel that would still be covered under warranty…
Each panels junction box comes with 1m of output cable MC4 Connectors

My working Plan is to mount 2 panels on each rack in shade…. Tape output cables secure…. Then physically mount on Bimini and confirm fit and output of each panel

My Solar newbie questions:
1… Any dangers or concern with that plan?
2… Using my AC/DC Clamp meter what is the best way of measuring each panels output?

This is what I have done to test panels:

- Start with all panels disconnected
- Cover one of the panels with something
- Connect that panel to the controller but insert an amp meter in one of the wires just before the controller and another one just after the controller. (In your case the panel makes more than 140W so it will make more than 10A after the controller, hence don´t insert a regular 10A series ammeter in there and use a clamp instead) . Set the series ammeter to the 10A scale.
- Connect enough DC loads to consume more watts than your panel´s rating. This is to make sure battery voltage will stay low to prevent the controller from constraining the power output of the panel. If you have difficulty in lining up enough load then it is time for the "inverter plus hair dryer" combo.
- Uncover the panel and read volts and amps before and after the controller.

I do not use a current clamp because I have never found one that is precise for loads of a few amps. I like to install a permanent A and Ah meter like the US$59 Watts Up downstream of the controller.
For one-off testing , the amp meter of most multitesters (that works in series) should be fine because they are precise enough (say to a few percentage points of scale) . Your panels are so big that a clamp may be good enough at least for after the controller.

Cheers
C