How to wire leads with VOC

[Davis White]

I will have six conductors coming from three strings going into my future combiner. I want to transition the wires to THWN. If I pre-connect everything upstream, presumably they'll be carrying 90V Open Circuit @ 10 ADC.

How do I deal with this?

A. Do it at night?
B. Hold off connecting the MC4s at the modules until afterwards? (A pain)
C. Some brighter idea?

Thank you!

 

[gnubie]

If you are trying to reduce the risk of working on wiring with 90VDC present I think you've really covered all the options apart from putting something over the panels (or a few of them which will cut their production heavily and reduce current from the string similarly. If the panel is covered well enough the array voltage would fall too but that requires very good cover not partial shading.

If I was trying to avoid the issue I'd leave one MC4 connector pair open in the string. That'd permit me to wire up the combiner without any risk of accidental shorts drawing arcs, or if its a hot sweaty day avoid getting a bit of current flowing across me. I'm assuming its not just plug in MC4 on the inputs too. Then once everything is secured, connect the final MC4 pair in the string then finally close the breaker / isolation on each string in the combiner.