Voltage vs. PWM controller & wire size
Ok, there is a recent thread out there MPPT vs. PWM and some post were a little confusing to me. Instead of hijacking his thread I started a new one. My set up is two 208 watt Sony panels with 28....
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smkettner wrote:
Bogart manual actually says up to 45 amp solar panel current rating is fine.
See technical specs page 4
This sounds great to maintain 30 amps when one panel is shaded.
Ah, this must be Trimetric monitor wizardry. This controller itself is brain-less, it's an add-on to Tri. Monitor circuits are used to control the actual controller, and will clip the amps when exceeding 31:
"Max 31A for full efficiency. May be safely used with panels up to 45A, however charging current will be reduced to protect charger".
Translation: controller in conjunction with Trimetric will handle 45A input but will clip it down to 31A.
Ex, you have 6*7.25A panels for total 43A, two are shaded, the remaining 4 run 29A. When #5-#6 clear out, they won't add anything over 31A because the rest will be clipped by Trimetric.
IMO, this clipping gives an advantage in low light, similarly to oversizing an array on MPPT. 45A array in overcast will drop to 20A, while 24A array - "normal maximum" for 30A PWM - would drop to 10A.
With 45A array makes sense getting 45A MPPT rather than 31A Bogart. Then you could have 45A output.
