Aluminium Busbar joints & supports

[gauravv]

Dear all,

We manufacture LT switchboards & use both aluminium & copper busbars in our panels. Aluminium being the most preferred. At present we make bolted connections by drilling holes in busbars but some manufacturers (elsteel, rittal,cubic,modis etc) promote busbar joints without drilling holes in busbar.
What i can make from their catalogues is they follow 2 or more busbar/ phase, use u type clamps along with 8.8 grade bolts, bellivile washer & plain heavy washer. Similarly they are constructing busbar supports using them. I've attached a file showing various application.

In this case the contact area is greatly reduced, steel bolt passing through busbar & use of sheet steel/stainless steel clamps.

Is this method feasible, what should be the clamp material, bolt material. Does less area of contact is countered by higher joint pressure. Kindly help to clarify.

 

[Lakey]

For comparison, you could evaluate the voltage drop across each type joint at a selected load (constant current). The clamping force should be sufficient to handle the peak current and other environmental issues, such as the Amb. Temp. and shock & vibration.

Test is best.

Regards,