Proper Ring terminal hole sizing verses connection stud or screw size.

[powerscol]

This may sound like a strange posts, but I have run into a dilemma. How critical is matching the ring terminal hole size to the connection size. Example #10 size ring on #8 screw, or using a 3/8" ring on a 5/16" stud. Will 5/16" ring fit an M8 stud (some include it in their description, others do not)? I have yet to find an #M8 stand alone ring in 2/0 and 4/0 (all labeled 5/16 (M8).

I want to use 8/3 cable with my future Go Power 3000w inverter (25 AMP Amp output) Maybe I am nuts. The best route gives me a 15' run (one direction) The inverter has #8 screws from what I can tell, and the transfer switch has #8 screws too. I am putting the inverter through a transfer switch. The switch can also turn off the WFCO converter when disconnecting shore power and powering the distribution panel.

I am also using 8 AWG PV cables on the solar due to run length and future expansion. I found 8 AWG PV wire and 8 AWG MC4 fittings at Continuous Resources. So I save a little bit buy using the same size connectors.

The Dilemma is finding good insulated 8 AWG #8 ring terminals - I can find 8 AWG #8 non-insulated terminals and use heat shrink I guess.

I have been searching the following recommended brands. Ancor, FTZ, Sta-Kon, AMP/Tyco, Panduit, Morris Products. Amazon has some of the brands, but prices are steep due to multi piece packs that contain more than I need. Pkys.com carry's Ancor and has the best pricing for small quantity but does not carry all the sizes in 8 AWG that I think I need. I have used PKYS before with good service.

First - is there any reason not to use non insulated terminals in the smaller wire sizes 8 AWG-14 AWG ten heat shrink. I have had issues in the past breaking the sheeting on pre-made heat shrink terminals during crimping.

Second - some sources say you can us a #10 hole size ring terminal on a #8 screw connection - is that true? Hole dimensions appear a bit big for the #8 screw and I don't want pull through.

Last - should I solve my problem by going 10/3 cable from the inverter (25 amp AC) to transfer switch and then to the distribution panel??? I'm guessing the 30 AMP service cable will be 10 AWG too. Then there is no issues on finding the terminals I need. Its AC so the 10/3 should be fine as I was told before. Any downside I might be missing?

Sometimes I think I over engineer my projects (wanting 8/3 cable for extra safety and measure).

Thanks for any answers or comments. Yes you can say I am nuts for wanting to use 8/3 cabling when 10/3 should work and easily solve my problems.

[NASCAR9]

When I did my conversion I dealt with Amazon and Mouser
https://www.mouser.com/?utm_source=b...Brand%20Mouser

[xrated]

Using the proper size ring connector is just as important as using the correct size wire for the current being carried. The current that flows through the wire also flows through the ring connector. Using a larger hole on a smaller stud simply limits the surface area that makes contact with the base of the stud terminal. The less surface area that contacts the stud base translates into less conductor surface for the amount of current that is flowing. If the surface gets to the point that it not enough to carry the current that is flowing, it will start heating up. Any connection that heats up enough will expand and contract and can contribute eventually to a loose connection.

[Wicked ace]

Using the proper size ring connector is just as important as using the correct size wire for the current being carried. The current that flows through the wire also flows through the ring connector. Using a larger hole on a smaller stud simply limits the surface area that makes contact with the base of the stud terminal. The less surface area that contacts the stud base translates into less conductor surface for the amount of current that is flowing. If the surface gets to the point that it not enough to carry the current that is flowing, it will start heating up. Any connection that heats up enough will expand and contract and can contribute eventually to a loose connection.

In addition to the good guidance Xrated gives the purpose of the stud and nut is to give a solid GAS TIGHT connection just as proper crimps do. The more surface area sandwiched between a nut and the buss the better and more enduring the connection.
Also note I said proper CRIMP. One thing novices do is to try a belt and suspenders approach to fasten connectors. A crimp using a proper tool provides a good mechanical gas tight connection. The foundation of a good solder connection is a good mechanical connection which a crimp is not. Soldering will only serve to loosen a crimped connection by expansion and contraction due to heating.