Does Vertical Busbar Trunking Need to be Seismic Proof

The forces generated by short circuit currents are vastly greater than seismic forces. Thus any bus bar system is already total overkill for seismic loads, which belong to the building in the first place. Claiming seismic compliance for bus bars is just "gilding the lily" = useless hype. (Unless the bus bars are supposed to hold up the building during an earthquake.)

That was worth 3 laughs--

Also note IEC 60439-2 i.e "Verification of structural strength" and "Verification of crushing resistance" are relevant tests that verify the ability of the bus way system to withstand mechanical load and impact with level of force stipulated by the standard

If things get to the stage of withstand seismic mechanical load and impact I think we've got to the point where electrical integrity is irrelevant. Just hope the protection survives intact and works.

In India (i am sure in California and elsewhere also) switchboards and similar electrical equipment meant for nuclear power stations need to satisfy seismic requirement.

Here is an extract from an Eaton publication:

Seismic Application:
Bus run assemblies are designed
to meet Uniform Building CodeT
(UBC) and California Building Code
Title 24 for Seismic Zones 4.3.2a.2b.1.
and 0. Completed guidelines for
proper supports are provided
on each seismic specified order

Here is the complete publication http://www.eaton.com/ecm/idcplg?IdcService=GET_FILE&dID=269816

While the sinusoidal force on the busbar is quite high as has been mentioned, seismic force is closer to a shock i have been given to understand.

I haven't worked much with this, but from what I understand, seismic forces even within Zone 4 are about 0.25g. So if a bus bar weighs 1 lb, it has to resist a seismic force of 4 ounces. Any damn bus bar can do that, for crying out loud. So what's the problem? (I admit that there might be some problem with flimsy enclosing structures such as a tinfoil cover, but is that really in question?)

(hell, I'm getting tired of inserting these things)

i don't doubt your numbers tornado, but i had to do a test on a motor-control centre once at the CPRI Lab in Bangalore for the Bhabha Atomic Energy Commission. The normal MCC failed by distorting, and we had to re-inforce the bottom-most structure by gussets. 3 mm sheet formed into channels for the foundation structure. i don't now remember the test levels, but it was quite severe.

http://www.cpri.in/testing/evrc/seismic_evrc.html