buss bar sizes, don't add up

[US1Fountain]

Have purchased a 600A and a 250A Blue Seas buss bar, and also the B/S's 150 SafetyHub fuse block, rated 350A.

The 600 buss measures 3/4" x 1" x 5 1/2"
The 250 buss measures 1/4" x 1" x 6 1/2"

The 350A fuseblock has a (+) buss of 1/8" x 1"x 5"
(-) buss of 1/8" x 3/4" x 5"

I can understand the 600A being so big, but how does the 350A SafetyHub rate higher than the 250A buss and do so with busses that are half the size, and even less considering the neg buss diminsions?

[delmarrey]

Are the materials the same too? Check the studs as well.

Different materials carry different loads. One maybe copper coated steel for corrosion resistance.

[US1Fountain]

The 2 buss bars are tin plated copper. 600 uses 3/8" SS studs.
250 and Safetyhub both use 5/16"

Not sure on material of the Safetyhub, other than non magnetic. So either tin plated copper or SS. No description that I can find. Just assumed B/S 's would be consistant thruout their line.

[CDunc]

or nickle plated copper

[delmarrey]

Originally Posted by US1Fountain

Just assumed B/S 's would be consistant thruout their line.

Good luck! Most everything is made in china now.

[GordMay]

Ampacities and Mechanical Properties of Rectangular Copper Busbars
Here ➥ Copper.org: Electrical: Busbar

[US1Fountain]

Originally Posted by GordMay

Ampacities and Mechanical Properties of Rectangular Copper Busbars
Here ➥ Copper.org: Electrical: Busbar

That certainly confuses the required bus size now.
The 250A is rated 400A, by dimensions. The 600A is somewhat several times underrated (no matching dim. listed). While the neg bus of the 350A Safetyhub is only good for 200A.