Where to get 2awg to 6awg pin adapters?

copec

Solar Enthusiast
Joined
Jan 23, 2021
Messages
77
I’m getting ready to move all my breakers to a subpanel, to properly have grid power go to my Growatt 12000t and then to the subpanel.

I’m going to use a 100A breaker from the main panel and 2awg wire to the inverter, and then 2awg wire from the inverter to the subpanel. The inverter has a 80A breaker for input and a 63A breaker for output, and calculating full charge current plus full bypass load is ~75A, anyways I plan on putting a 100A transfer switch to bypass the inverter for maintenance too, so 2awg for the possible 100A is proper anyways.

The largest wire the inverter accepts is 6awg and I wanted to minimize losses, plus it is breakered for 80A which I believe is above the 6awg max anyways.
 

copec

Solar Enthusiast
Joined
Jan 23, 2021
Messages
77
Have you compared the losses between 2awg and 6awg?
Let me see:

At 25C
2 awg is ~1.59*10^-4 ohm per foot
6 awg is ~4.03*10^-4 ohm per foot

I would say the wire run is 10ft, so 20ft round trip

0.000159 * 20 = 0.00318
0.000403 * 20 = 0.00806

So at 75A (18kw) it is going to be burning ~18W in the 2 awg wire, which is 0.1% loss, and in 6 awg wire it would be burning ~45W, which is 0.25% loss. I've gotten my daily usage average in the non-AC season to 25kw/h a day, so with an average ~1kw power load it is even more negligible.

During the summer there will be times with the AC and Drier running when we are talking about 8-10kw load during intervals a few minutes at time, but still negligible I suppose.
 

snoobler

Solar Honey Badger
Joined
Jul 10, 2020
Messages
8,430
Location
HBR, AZ
I ran some estimates with a voltage drop calculator and saw a similar ratio.
 

copec

Solar Enthusiast
Joined
Jan 23, 2021
Messages
77
I realized that it would be cheaper and easier to do an interlock in the secondary panel, and I can use 2awg for the grid inverter bypass breaker and 6 awg for the inverter breaker.
 
Top